Co-reporter:Zhiming Zhang, Yangguang Li, Yonghui Wang, Yanfei Qi and Enbo Wang
Inorganic Chemistry September 1, 2008 Volume 47(Issue 17) pp:7615-7622
Publication Date(Web):August 5, 2008
DOI:10.1021/ic800479k
The reaction between K12[H2P2W12O48] and CuCl2 in a NaCl aqueous solution assisted with organoamines (1,2-ethylenediamine (en), 1,6-hexamethylene diamine (hn), or both) leads to the isolation of three compounds: K4Na10[α1-CuP2W17O60(OH)]2·∼58H2O (1), Na2[H2en][H2hn]0.5[Cu(en)2]4.5[α1-CuP2W17O60(OH)]2·∼43H2O (2), and Na3[H2hn]2.5[α1-P2W17O60Cu(OH)2]·∼14H2O (3). The polyoxoanion [α1-CuP2W17O60(OH)]214− in 1 and 2 exhibits a double-Dawson-type polyoxoanion that consists of two α1-type mono-Cu-substituted Wells—Dawson anions, which can be synthesized by both the conventional aqueous solution method and the hydrothermal technique. Furthermore, the double-Dawson-type polyoxoanions in 2 are linked by the [Cu(en)2]2+ bridges to form 2-D networks, which are further packed into a 3-D supramolecular porous framework via extensive hydrogen bonding interactions, exhibiting two types of tunnels (A and B). Compound 3 possesses a 3-D supramolecular framework with 1-D tunnels constructed from the α1-type mono-Cu-substituted Wells—Dawson anion. The magnetic studies of compounds 1 and 2 indicate that weak antiferromagnetic interactions exist in these two compounds.
Co-reporter:Xin-Bao Han, Zhi-Ming Zhang, Teng Zhang, Yang-Guang Li, Wenbin Lin, Wansheng You, Zhong-Min Su, and En-Bo Wang
Journal of the American Chemical Society April 9, 2014 Volume 136(Issue 14) pp:5359-5366
Publication Date(Web):March 24, 2014
DOI:10.1021/ja412886e
A series of all-inorganic, abundant-metal-based, high-nuclearity cobalt–phosphate (Co–Pi) molecular catalysts [{Co4(OH)3(PO4)}4(SiW9O34)4]32– (1), [{Co4(OH)3(PO4)}4(GeW9O34)4]32– (2), [{Co4(OH)3(PO4)}4(PW9O34)4]28– (3), and [{Co4(OH)3(PO4)}4(AsW9O34)4]28– (4) were synthesized and shown to be highly effective at photocatalytic water oxidation. The {Co16(PO4)4} cluster contains a Co4O4 cubane which is structurally analogous to the [Mn3CaO4] core of the oxygen-evolving complex (OEC) in photosystem II (PSII). Compounds 1–4 were shown to be the first POM-based Co–Pi-cluster molecular catalysts for visible light-driven water oxidation, thus serving as a functional model of the OEC in PSII. The systematic synthesis of four isostructural analogues allowed for investigating the influence of different heteroatoms in the POM ligands on the photocatalytic activities of these Co–Pi cluster WOCs. Further, the POM-based photocatalysts readily recrystallized from the photocatalytic reaction systems with the polyoxoanion structures unchanged, which together with the laser flash photolysis, dynamic light-scattering, 31P NMR, UV–vis absorption, POM extraction, and ICP-MS analysis results collectively confirmed that compounds 1–4 maintain their structural integrity under the photocatalytic conditions. This study provides not only a valuable molecular model of the “Co–Pi” catalysts with a well-defined structure but also an unprecedented opportunity to fine-tune high-nuclearity POM clusters for visible light-driven water splitting.
Co-reporter:Hong-Fei Shi, Gang Yan, Yi Zhang, Hua-Qiao Tan, Wen-Zhe Zhou, Yuan-Yuan Ma, Yang-Guang Li, Weilin Chen, and En-Bo Wang
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 1) pp:
Publication Date(Web):December 14, 2016
DOI:10.1021/acsami.6b13009
Photocatalysis, a promising technology platform to address the environmental problems, has been attracting considerable attention. In this paper, Ag/AgxH3–xPMo12O40 (simplified as Ag/AgHPMo12) nanowires have been synthesized by a facile solid reaction route and in situ photodeposited method. The results of SEM and TEM indicate that the diameters of AgHPMo12 nanowires are about 45 ± 10 nm, and Ag nanoparticles with diameters in the range of 5–15 nm are uniformly anchored on the surface of AgHPMo12 nanowires. The Ag content in the Ag/AgHPMo12 composite was manipulated by the light irradiation time (Ag/AgHPMo12-x; x stands for the irradiation time; x = 2, 4, 6, 8 h, respectively). With increasing irradiation time, the light absorption of as-synthesized samples in the visible region was gradually enhanced. The Ag/AgHPMo12-4 exhibits the best photocatalytic performance for the degradation of methyl orange and reduction of Cr2O72– under visible-light (λ > 420 nm) irradiation. The study of the photocatalytic mechanism reveals that both Ag and AgHPMo12 can be excited by visible light. The photoinduced electrons were transferred from AgHPMo12 to metallic Ag, and combined with the Ag plasmonic holes. The Ag plasmonic electrons were trapped by O2 to form ·O2–, or directly reduced Cr2O72– to Cr3+. Meanwhile, the ·O2– species and the photogenerated holes of AgHPMo12 were used to oxidize MO or i-PrOH; thus, they showed highly efficient and recyclable photocatalytic performance for removing the organic and inorganic pollutants.Keywords: Ag; nanowires; photodegradation; photoreduction; polyoxometalates;
Co-reporter:Xin-Bao Han, Chao Qin, Xin-Long Wang, Yuan-Zhi Tan, Xin-Jing Zhao, En-Bo Wang
Applied Catalysis B: Environmental 2017 Volume 211(Volume 211) pp:
Publication Date(Web):15 August 2017
DOI:10.1016/j.apcatb.2017.04.057
•Biomimetic noble-free polyoxometalates with adjustable {Ni4O4} cubane cores for visible light-driven H2 evolution.•Develop a reliable synthetic strategy for directional synthesis of TM cubane-containing POMs.•Compounds 1−3 as the homogeneous catalysts show high photocatalytic activities.•Reveal the relationship between the number of cubanes and catalytic performance.By artificial mimic of the natural [FeFe]-hydrogenases, a series of polyoxometalate-based high-nuclear Ni clusters containing a varying number of {Ni4O4} cubane cores, K1.5Na26.5[{Ni4(OH)3(PO4)}4(A-PW9O34)4]·62H2O (1), Na28[{Ni4(OH)3(PO4)}4(A-PW9O34)2(B-PW9O34)2]·102H2O (2), and Na28[{Ni4(OH)3(VO4)}4(B-PW9O34)4]·74H2O (3), were synthesized and systematically characterized. Compounds 1−3 contain {Ni16(XO4)4(OH)12} (X = P, V) core encapsulated by the trivacant A-/B-{PW9O34} ligands. Compounds 1−3 as homogeneous catalysts for visible-light-driven H2 evolution indicate that they not only show high photocatalytic performance (High TON of 578.8, 679.1, and 931.1 for 1−3 were achieved, respectively), but also their catalytic performance was improved with the increasing number of {Ni4O4} cubanes. Multiple stability experiments confirm that compounds 1−3 maintain their structure intact under the photocatalytic conditions. The above research provides a platform for mimicking the structures of natural hydrogenases to further explore more efficient and inexpensive H2 evolution catalysts.Three bionic high-nuclear Ni clusters containing a varying number of {Ni4O4} cubane cores were oriented-synthesized by polyoxometalate isomer-regulated strategy. They not only show high photocatalytic performance, but also their photocatalytic performance was improved with the increasing number of {Ni4O4} cubanes, which provides a platform for mimicking the structures of natural hydrogenases to further explore more efficient and inexpensive H2 evolution catalysts.Download high-res image (216KB)Download full-size image
Co-reporter:Yi-Jing Wang;Wei-Lin Chen;Li Chen;Xiao-Tao Zheng;Sha-Sha Xu
Inorganic Chemistry Frontiers 2017 vol. 4(Issue 3) pp:559-565
Publication Date(Web):2017/03/14
DOI:10.1039/C6QI00570E
Sandwich-type polyoxometalates K6Na2Ni2[Ni4(H2O)2(SiW9O34)2]·30H2O(Ni4), K6Na2Co2[Co4(H2O)2(SiW9O34)2]·30H2O(Co4) and K10[Ni(H2O)2(γ-SiW10O35)2]·13.25H2O(Ni1) were doped into TiO2 separately and applied as photoanodes for dye-sensitized solar cells (DSSCs) for the first time, enhancing the current intensity and photoelectric conversion efficiency of the cells. The TiO2 and POM@TiO2 used in this paper were synthesized by a modified sol–gel method. The Jsc of pure P25 is 15.84 mA cm−2, the Voc is 0.637 V, the FF is 0.564, and the η is 5.69%. The Jsc of the prepared TiO2 is 16.48 mA cm−2, the Voc is 0.68 V, the FF is 0.537 and the η is 6.01%, which is a higher efficiency than that of pure P25, therefore the POMs@TiO2 were directly used in photoanodes without being formed into composites with P25 in this paper. The Jsc of 0.8% Ni4@TiO2 is 18.79 mA cm−2, the Voc is 0.71 V, the FF is 0.595 and the η is 7.94%, which is 32.1% higher than that of the prepared TiO2 based DSSC. 0.8% Co4@TiO2 and 0.8% Ni1@TiO2 modified photoanodes obtained power conversion efficiencies of 6.22% and 6.17%. The electron lifetimes of the self-prepared TiO2 and 0.8% Ni4@TiO2 are 13.5 ms and 28 ms respectively, calculated from a bode plot. Among the three kinds of sandwich-type POMs mentioned in this paper, the 0.8% Ni4 modified photoanode in DSSCs exhibited the best performance in enhancing light harvesting and reducing electron recombination. The energy levels of Ni4 were also investigated.
Co-reporter:Jiabo Wang, Weilin Chen, Xinlong Wang, Enbo Wang
Electrochimica Acta 2017 Volume 251(Volume 251) pp:
Publication Date(Web):10 October 2017
DOI:10.1016/j.electacta.2017.08.151
•WxC/NG-10 was synthesized via a simple two-step calcination method.•WxC/NG-10 exhibited the highly efficient and long-term stable electrocatalytic hydrogen evolution reaction.•WxC/NG-10 was firstly attempted to apply to OER.Tungsten carbides materials exhibit highly efficient activity for hydrogen evolution reaction (HER) as promising non-precious electrocatalysts. Herein, a N-doped graphene (NG) supported tungsten carbides composite material (WxC/NG-10, x = 1, 2, x is stoichiometric number of W, 10 is the mole quantity of tungsten in the precursors, mmol) was directly synthesized with a simple method by two-step calcining the mixture of sodium tungstate dihydrate (Na2WO4·2H2O), dicyandiamide (DCDA) and glucose anhydrous (GA), which was characterized by HRTEM, FE-SEM, XRD, XPS, EDX, BET and Raman, and estimated the electrocatalytic activity by the LSV, Tafel curves, and electrochemical impedance spectrum (EIS). The investigations indicate that WxC/NG-10, as an electrocatalyst for HER, achieves a lower overpotential of only 77.82 mV at the current density of 10 mA cm−2 and a Tafel slope of 45.95 mV dec−1 in 0.5 mol L−1 H2SO4 aqueous. Additionally, the WxC/NG-10 has also possessed an electrocatalytic oxygen evolution reaction (OER) activity in 1.0 mol L−1 KOH aqueous with a lower overpotential of 467.6 mV and a Tafel slope of 36.2 mV dec−1. And after 10000 cycles the electrocatalytic active of WxC/NG-10 decrease 24.63% and 19.35% for HER and OER, respectively. The modification of WxC has improved the activity of NG materials in electrocatalytic applications.A N-doped graphene supported WxC composite material is directly synthesized by a simple two-step calcination method, which enhances the electrocatalytic HER activity and firstly tries to apply to OER.Download high-res image (243KB)Download full-size image
Co-reporter:Xiang-Wei Guo;Xiao-Hong Li;Zhu-Jun Liu;Wei-Lin Chen;Xiao-Tao Zheng;Zhong-Min Su
Inorganic Chemistry Frontiers 2017 vol. 4(Issue 7) pp:1187-1191
Publication Date(Web):2017/07/11
DOI:10.1039/C7QI00160F
Photosensitizers play a crucial role in p-type dye-sensitized solar cells (p-DSSCs). In this study, we first introduced two Dawson-type transition metal-substituted polyoxometalate dyes to co-sensitize the NiO electrode and achieved an overall power conversion efficiency (PCE) of 0.0464%, which is the highest value reported for inorganic photosensitizers in p-DSSCs.
Co-reporter:Zhu-Jun Liu, Xin-Long Wang, Chao Qin, Zhi-Ming Zhang, Yang-Guang Li, Wei-Lin Chen, En-Bo Wang
Coordination Chemistry Reviews 2016 Volume 313() pp:94-110
Publication Date(Web):15 April 2016
DOI:10.1016/j.ccr.2015.12.006
The {Mn4O5Ca} cluster of photosystem II is a well-known cubane-like transition-metal (TM) cluster that plays important roles in solar energy conversion. The artificial synthesis of cubane-like TM clusters and their interesting potential applications have been widely studied. Most of them were isolated by use of organic ligands, and therefore their potential applications were essentially restricted to organic solvents because of their limited stability in aqueous solution. In recent decades, lacunary polyoxometalates (POMs) composed of WVI/MoVI centers have been used to replace organic ligands as stable and oxidative-resistant pure-inorganic multidentate ligands to construct water-soluble and water-stable molecular clusters. In the course of the mimicking of the {Mn4O5Ca} subsite of photosystem II, significant advances have already been made in POM-assisted artificial synthesis of TM cubanes. Compared with classic cubane-like TM clusters, these POM-based TM cubane clusters can not only dissolve in organic solvents by virtue of a simple phase-transfer reaction but also display excellent aqueous stability. Consequently, the synthesis of these pure-inorganic cubane clusters offers a great opportunity for expanding the applications of cubane-like TM clusters. This review focuses on the synthetic strategies for, structures of, and applications of these POM-based TM cubane clusters, particularly highlighting how POMs can be used as the inorganic ligands to construct cubane-like TM clusters. The purpose of this review is to give a representative and comprehensive overview of the work done so far in this emerging field.
Co-reporter:Zhi-Ming Zhang, Xiaopin Duan, Shuang Yao, Zhishu Wang, Zekai Lin, Yang-Guang Li, La-Sheng Long, En-Bo Wang and Wenbin Lin
Chemical Science 2016 vol. 7(Issue 7) pp:4220-4229
Publication Date(Web):09 Mar 2016
DOI:10.1039/C5SC04408A
We report the crystallization of homochiral polyoxometalate (POM) macroanions {CoSb6O4(H2O)3[Co(hmta)SbW8O31]3}15− (1, hmta = hexamethylenetetramine) via the counter cation-mediated chiral symmetry breaking and asymmetric autocatalytic processes. In the presence of low Co2+ concentrations both Δ- and Λ-enantiomers of 1 formed in the reaction, crystallizing into the racemic crystal rac-1. At a high Co2+ concentration, the polyoxoanion enantiomers showed a high level of chiral recognition via H-bonding interactions to crystallize into enantiopure crystals of Δ- or Λ-[Co(H2O)6{CoSb6O4(H2O)3[Co(hmta)SbW8O31]3}]13−. During crystallization, a microscale symmetry-breaking event and a nonlinear asymmetric autocatalysis process make the enantiomers crystallize in different batches, which provides an opportunity to isolate the homochiral bulk materials. The defined structures of the racemic and homochiral crystals thus provide a molecular-level illustration that H-bonding interactions are responsible for such high-level chiral recognition, in a process similar to the supramolecular chirality frequently observed in biology. These POM macroanions showed a high cytotoxicity against various cancer cells, particularly ovarian cancer cells. The antitumor activity of these compounds resulted at least in part from the activation of the apoptotic pathways, as shown by the flow cytometry, Annexin V staining, DNA ladder, and TUNEL assay, likely by blocking the cell cycle and complexing with proteins in cells. The POM macroanions reported herein provide promising and novel antitumor agents for the potential treatment of various cancers.
Co-reporter:Li Chen, Weilin Chen, Huaqiao Tan, Jiansheng Li, Xiaojing Sang and Enbo Wang
Journal of Materials Chemistry A 2016 vol. 4(Issue 11) pp:4125-4133
Publication Date(Web):10 Feb 2016
DOI:10.1039/C5TA10260J
Quantum dot sensitized solar cells with high theoretical conversion efficiency, low production cost and a simple production process have received great attention in recent years. For CdSe-sensitized cells, the most significant defect of CdSe is that it has the weak absorption between 550 and 600 nm and no absorption after 650 nm, so it is crucial to find a wide spectrum photosensitizer to make up for the defect. Here, wide spectrum and pure inorganic Donor–Acceptor (D–A) Type Polyoxometalate (POM) K6H4[α-SiW9O37Co3(H2O)3]·17H2O (denoted as T) is firstly introduced into QDSCs as a collaborative cosensitizer with CdSe. The T has a visible characteristic peak centering between 550 and 600 nm, and also has stronger absorption after 650 nm, which could make up for the defect of CdSe to constitute a wide spectrum of absorption. The fluorescence spectrum, surface photovoltage spectrum, ultraviolet photoelectron spectroscopy spectrum and solid diffuse spectrum were used to explore the photosensitivity of T. In addition, the D–A type POM can act as a good intermediate for the injection of electrons and improve the visible photocurrent response; meanwhile, it can obviously reduce the dark current and increase the electron lifetime, which can solve the problem about the high recombination at the QD/TiO2/electrolyte interface. In general, the best photovoltaic performance of T and CdSe cosensitized solar cells is increased to 6.59% (Jsc = 18.37 mA cm−2, Voc = 0.57 V, FF = 0.63), which is improved by 32.33% compared to those of the pure CdSe-sensitized cells (Jsc = 16.20 mA cm−2, Voc = 0.50 V, FF = 0.61, η = 4.98%).
Co-reporter:Chun-Hui Shan, Hong Zhang, Wei-Lin Chen, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2016 vol. 4(Issue 9) pp:3297-3303
Publication Date(Web):22 Jan 2016
DOI:10.1039/C5TA10601J
A pure inorganic donor–acceptor (D–A) type polyoxometalate K6H4[α-SiW9O37Co3(H2O)3]·17H2O (SiW9Co3)/reduced graphene oxide (RGO) nanocomposite was employed to dye-sensitized solar cells (DSSCs) for the first time, building up a wide spectrum for the photoanode of a DSSC. Raman, XRD, TEM, and EDS have proved that SiW9Co3 was loaded on RGO, and then the SiW9Co3/RGO doped nanocomposite in P25 was applied to be the photoanode of the DSSCs. In this paper the performance of SiW9Co3/RGO-3@P25 is the best. The Jsc of pure P25 is 13.74 mA cm−2, Voc is 0.679 V, FF is 0.598 and η is 5.37%, while the Jsc of SiW9Co3/RGO-3@P25 is 17.5 mA cm−2, Voc is 0.705 V, FF is 0.558 and η is enhanced to 6.88%, which is 28.05% higher than for a pure P25-based cell in a DSSC. OCVD indicates that SiW9Co3/RGO can delay the electron–hole recombination. In a Bode plot the electron lifetimes of SiW9Co3/RGO-3@P25 and P25 are 4.86 ms and 3.81 ms respectively, which also further clarifies that the SiW9Co3/RGO doped nanocomposite can extend the lifetime of electrons and also plays an important role in the photoanode of the DSSCs. This result is beneficial to the application of DSSCs in future industry.
Co-reporter:Lifei He, Li Chen, Yue Zhao, Weilin Chen, Chunhui Shan, Zhongmin Su, Enbo Wang
Journal of Power Sources 2016 Volume 328() pp:1-7
Publication Date(Web):1 October 2016
DOI:10.1016/j.jpowsour.2016.07.085
•Highly dispersed POM nanoparticles were synthesized by micelle directed method.•TiO2 composited with POM nanoparticles was studied as photoanodes.•Both high dispersion and nanoscale increased the active site.•POM addition accelerated electron transition and retarded electron recombination.•The composite yielded an efficiency improvement from 5.9% to 8.4%.In this work, two kinds of polyoxometalate (POM) nanoparticles with controlled shapes and structures were synthesized by micelle directed method and then composited with TiO2 via calcination to remove the surfactants owing to the excellent electronic storage and transmission ability of POM, finally obtaining two kinds of TiO2 composites with highly dispersed and small-sized POM nanoparticles (∼1 nm). The TiO2 composites were then induced into the photoanodes of dye-sensitized (N719) solar cells (DSSCs). The separation of electron-holes becomes more favorable due to the nanostructure and high dispersion of POM which provide more active sites than pure POM tending to agglomeration. The TiO2 composite photoanodes finally yielded the power conversion efficiency (PCE) of 8.4% and 8.2%, respectively, which were 42% and 39% higher than the pristine TiO2 based anodes. In addition, the mechanisms of POM in DSSC are proposed.Two polyoxometalate (POM) nanoparticles with controlled shape and structure were synthesized by micelle directed method, and then composited with TiO2 via calcination to remove the surfactant to obtain TiO2 complexes with highly dispersed and small-sized polyoxometalate nanoparticles, which were firstly applied as photoanodes for dye-sensitized (N719) solar cells with enhanced photovoltaic performance.
Co-reporter:Tingting Wang, Ying Lu, Hongli Wu, Enbo Wang
Inorganica Chimica Acta 2016 Volume 446() pp:13-18
Publication Date(Web):1 May 2016
DOI:10.1016/j.ica.2016.02.065
•The catalyst is a rare example of surfactant-encapsulated POMs formed by high-nuclear poly-{HPMo6} POMs.•The removal of sulfide could reach above 98% under the optimal conditions.•The catalyst can be reused 5 times with high recycling efficiency.Two novel surfactant-encapsulated high-nuclear polyoxometalates catalysts (DODA)20[(HPMo6O21)4(O2CCH2CO2)6]·27H2O and (DODA)10[(HPMo6O21)2(C2O4)3]·11H2O have been prepared and characterized by TG, FT-IR, 1H NMR and UV–Vis. They were used for the oxidative desulfurization of model oil containing sulfur compounds such as dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), benzothiophene (BT) with H2O2 as an oxidant under mild conditions. The removal of DBT, 4,6-DMDBT and BT could reach above 98% under the optimal conditions of n(S)/n(catalyst)/n(H2O2) = 220:1:880 at 60 °C for 2.5 h, 4.5 h and 5 h respectively, which improved to be a promising catalyst in the ODS process. The oxidative reactivity of the sulfur-containing compounds decreased according to DBT > 4,6-DMDBT > BT. We investigated the main factors affecting the process including temperature, the polymeric structures of catalysts, and O/S (H2O2/DBT) molar ratio in detail. Moreover, the catalyst can be reused 5 times with high recycling efficiency.Two new surfactant-encapsulated high-nuclear polyoxometalate catalysts composed of the poly-{PMo6} POMs, (DODA)20[(HPMo6O21)4(O2CCH2CO2)6]·27H2O (SEP-1) and (DODA)10[(HPMo6O21)2(C2O4)3]·11H2O (SEP-2), have been synthesized, and used as catalysts for the oxidative desulfurization of model oil with H2O2 as an oxidant. The removal of sulfide could reach above 98% under the optimal conditions.
Co-reporter:Ting-ting Wang, Ying Lu, Ding Liu, En-bo Wang
Inorganic Chemistry Communications 2016 Volume 69() pp:47-51
Publication Date(Web):July 2016
DOI:10.1016/j.inoche.2016.04.014
•A rare example of organic-inorganic hybrid based on [Mn2V22O64]10 − polyoxoanion has been synthesized.•A three-dimensional supramolecular structure is formed in the hybrid through hydrogen bond.•The hybrid exhibits high activity in the oxidation of sulfide.A new organic-inorganic hybrid compound constructed from [Mn2V22O64]10 − units, H6[(C6H4NO2Cu(H2O)4)]2[Mn2V22O64]·28H2O 1, has been synthesized and characterized by single-crystal X-ray diffraction, IR, powder X-ray diffraction (XPRD) and TG. Compound 1 is composed of dimeric [Mn2V22O64]10 − polyoxoanions, metal-organo fragments [(C6H4NO2Cu(H2O)4)]2 + and lattice water molecules. Moreover, a three-dimensional supramolecular structure is formed in 1 by the extensive hydrogen bond interaction among the terminal oxygen atoms of [Mn2V22O64]10 − anions, the coordinated waters of Cu2 + ions and crystal water molecules. Compound 1 exhibits remarkable catalytic activity for the heterogeneous oxidation of sulfides under mild condition.A new organic-inorganic hybrid compound constructed from [Mn2V22O64]10 − units, H6[(C6H4NO2Cu(H2O)4)]2[Mn2V22O64]·28H2O, has been synthesized and it exhibits remarkable catalytic activity for the heterogeneous oxidation of sulfides under mild condition.
Co-reporter:Xin-Bao Han; Yang-Guang Li; Zhi-Ming Zhang; Hua-Qiao Tan; Ying Lu
Journal of the American Chemical Society 2015 Volume 137(Issue 16) pp:5486-5493
Publication Date(Web):April 13, 2015
DOI:10.1021/jacs.5b01329
Three new polyoxometalate(POM)-based polynuclear nickel clusters, Na24[Ni12(OH)9(CO3)3(PO4)(SiW9O34)3]·56H2O (1), Na25[Ni13(H2O)3(OH)9(PO4)4(SiW9O34)3]·50H2O (2), and Na50[Ni25(H2O)2OH)18(CO3)2(PO4)6(SiW9O34)6]·85H2O (3) were synthesized and structurally characterized. Compounds 1–3 contain {Ni12}, {Ni13} and {Ni25} core, respectively, connected by the inorganic {OH}, {PO4} and/or {CO3} linkers and encapsulated by the lacunary A-α-{SiW9O34} POM units. Compound 3 represents the currently largest POM-based Ni clusters. All three compounds contain {Ni3O3} quasi-cubane or {Ni4O4} cubane units, which are similar to the natural oxygen-evolving center {Mn4O5Ca} in photosystem II (PSII). Visible light-driven water oxidation experiments with compounds 1–3 as the homogeneous catalysts indicate that all three compounds show good photocatalytic activities. The O2 evolution amount corresponds to a high TON of 128.2 for 1, 147.6 for 2, and 204.5 for 3, respectively. Multiple experiments including dynamic light-scattering, UV–vis absorption, catalysts aged experiments, tetra-n-heptylammonium nitrate (THpANO3) toluene extraction, and capillary electrophoretic measurements results confirm that compounds 1–3 are dominant active catalysts but not Ni2+ ions(aq) or nickel oxide under the photocatalytic conditions. The above research results indicate a new and all-inorganic polynuclear Ni-based structural model as the visible light-driven water oxidation catalysts.
Co-reporter:Jian-Sheng Li, Xiao-Jing Sang, Wei-Lin Chen, Lan-Cui Zhang, Zai-Ming Zhu, Yang-Guang Li, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 28) pp:14573-14577
Publication Date(Web):12 Jun 2015
DOI:10.1039/C5TA03259H
A strategy was developed for the first time to fabricate highly dispersed and small-sized polyoxometalate nanoparticles loaded on a TiO2 film by using MIL-101 to prevent agglomeration, and calcination to break the metal–organic framework, which can result in performance improvement of quantum dot solar cells.
Co-reporter:Dan Xu, Wei-Lin Chen, Jian-Sheng Li, Xiao-Jing Sang, Ying Lu, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 19) pp:10174-10178
Publication Date(Web):31 Mar 2015
DOI:10.1039/C5TA01578B
SiW11V/graphene nanocomposite was first prepared and introduced into TiO2 film. It showed a significant photocurrent response, which can be attributed to the photoinduced electrons of SiW11V. This work provides a promising strategy for exploring POMs sensitizers with lower energy levels than the CB of TiO2.
Co-reporter:Hongfei Shi, Huaqiao Tan, Wan-bin Zhu, Zaicheng Sun, Yuejia Ma and Enbo Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 12) pp:6586-6591
Publication Date(Web):18 Feb 2015
DOI:10.1039/C4TA06736C
A series of Cr-doped Bi4Ti3O12/Bi2Ti2O7 (BTO) heterostructure fibers have been synthesized via a one-step, facile and economical electrospinning/calcination process. SEM and TEM results reveal that the diameters of the as-prepared fibers are 100 ± 30 nm. The light adsorption of Bi4Ti3O12 and Bi2Ti2O7 in the fibers has been remarkably improved by Cr doping. With increased Cr doping, XRD and XPS show that the amount of Bi2Ti2O7 increases in the fibers. As a result, the Bi4Ti3O12/Bi2Ti2O7 heterojunction structure is enhanced, which further promotes the charge separation of photogenerated charge carriers. Photocatalytic tests indicated that the as-prepared Cr-doped Bi4Ti3O12/Bi2Ti2O7 fibers exhibit good photocatalytic activity for photodegradation of methyl orange (MO) under visible-light irradiation.
Co-reporter:Jian-Sheng Li, Xiao-Jing Sang, Wei-Lin Chen, Lan-Cui Zhang, Zai-Ming Zhu, Teng-Ying Ma, Zhong-Min Su, and En-Bo Wang
ACS Applied Materials & Interfaces 2015 Volume 7(Issue 24) pp:13714
Publication Date(Web):June 1, 2015
DOI:10.1021/acsami.5b03948
In the field of material chemistry, it is of great significance to develop abundant and sustainable materials for solar energy harvesting and management. Herein, after evaluating the energy band characteristics of 13 kinds of polyoxometalates (POMs), the trisubstituted POM compound K6H4[α-SiW9O37Co3(H2O)3]·17H2O (SiW9Co3) was first studied due to its relatively smaller band gap (2.23 eV) and higher lowest unoccupied molecular orbital (LUMO) level (−0.63 V vs NHE). Additionally, the preliminary computational modeling indicated that SiW9Co3 exhibited the donor–acceptor (D–A) structure, in which the cobalt oxygen clusters and tungsten skeletons act as the electron donor and electron acceptor, respectively. By employing SiW9Co3 to modify the TiO2 film, the visible photovoltaic and photocurrent response were both enhanced, and the light-induced photocurrent at 420 nm was improved by 7.1 times. Moreover, the highly dispersive and small sized SiW9Co3 nanoclusters loading on TiO2 were successfully achieved by fabricating the nanocomposite film of {TiO2/SiW9Co3}3 with the layer-by-layer method, which can result in the photovoltaic performance enhancement of dye-sensitized solar cells (DSSCs), of which the overall power conversion efficiency was improved by 25.6% from 6.79% to 8.53% through the synergistic effect of POMs and Ru-complex.Keywords: donor−acceptor; photovoltaic; polyoxometalate; TiO2; visible;
Co-reporter:Sha-Sha Xu, Wei-Lin Chen, Yan-Hua Wang, Yang-Guang Li, Zhu-Jun Liu, Chun-Hui Shan, Zhong-Min Su and En-Bo Wang
Dalton Transactions 2015 vol. 44(Issue 42) pp:18553-18562
Publication Date(Web):16 Sep 2015
DOI:10.1039/C5DT02992A
A di-vanadium-substituted Lindqvist-type polyoxometalate [Cu(C12H8N2)2]2[V2W4O19]·4H2O (1) was hydrothermally synthesized and characterized structurally by single crystal X-ray diffraction analysis. X-ray photoelectron spectroscopy and energy disperse spectroscopy tests further prove the existence of vanadium. Ultraviolet photoelectron spectroscopy and density functional theoretical studies indicate that the energy level of 1 matches well with the conduction band of the TiO2. Furthermore, considering the semiconductor-like nature of 1 and the introduction of transition metal element Cu synchronously extends the absorption to the visible region, which should also be beneficial to the photovoltaic device performance. 1-Doped TiO2 composites (denoted as 1@TiO2) have been successfully fabricated by a simple sol–gel method, and introduced into the dye-sensitized solar cells (DSSCs) as co-sensitizers in N719-sensitized photoanodes by mixing 1@TiO2 with P25 nanoparticles with different weight ratios to enhance the photoelectric conversion efficiency. The investigations show that the DSSC assembled with 1@TiO2/19P25 photoanode has the best performance and the overall improvement of the efficiency is 21.6% compared with pure P25. Furthermore, the electrochemical impedance spectroscopy and open-circuit voltage decay investigations show that the cosensitization of 1 and N719 can promote electron transfer and restrain charge recombinations in the DSSCs, resulting in a longer electron lifetime.
Co-reporter:Ding Liu, Ying Lu, Hua-Qiao Tan, Ting-Ting Wang, and En-Bo Wang
Crystal Growth & Design 2015 Volume 15(Issue 1) pp:103-114
Publication Date(Web):December 3, 2014
DOI:10.1021/cg500955d
A family of polyoxometalate compounds based on 1:13 polyoxoanions [MnV13O38]7–, organic molecules, and lanthanide cations, H[{La2(DMF)5(H2O)4}{MnV13O38}]·DMF·5H2O (1), H[{Ce2(DMF)2(H2O)7}{MnV13O38}]·0.5DMF·5.5H2O (2), H2[{K(H2O)2}2{Nd(DMF)(H2O)3}{MnV13O38}]·5H2O (3), H[{Ln2(C6H5NO2)3(H2O)6}{[MnV13O38}]·C6H5NO2·10H2O (Ln = La 4, Ce 5), and H2.5[{Pr(C6H5NO2)(H2O)3.5}{Pr0.5(H2O)2}{MnV13O38}]·0.5C6H5NO2·10H2O (6) (DMF = N,N-dimethylformamide; C6H5NO2 = isonicotinic acid), have been obtained utilizing a conventional method of aqueous solution and further characterized by elemental analysis, IR spectrum, UV spectrum, thermogravimetric analysis, and single-crystal X-ray diffraction. Compounds 1 and 2 exhibit a one-dimensional extended chain structure constructed by [MnV13O38]7– and lanthanide-organic coordination linkage, while compound 3 reveals three-dimensional (3D) open framework formed by polyoxoanion-lanthanide chains and potassium cations. Compounds 4–6 exhibit 3D supramolecular framework architectures based on [MnV13O38]7– polyoxoanions and lanthanide-organic coordination units. These compounds represent the first examples of extended organic–inorganic hybrids built up by [MnV13O38]7– building blocks and rare earth cations. The influences of the lanthanide contraction effect on the structural alterations from 1 to 3 and from 4 to 6 have been disscussed. The electrochemical and electrocatalytic properties for compounds 1–6 have been studied. Magnetic studies indicate that antiferromagnetic interactions exist in compounds 1–6.
Co-reporter:Hong-Li Wu, Zhi-Ming Zhang, Yang-Guang Li, Xin-Long Wang and En-Bo Wang
CrystEngComm 2015 vol. 17(Issue 33) pp:6261-6268
Publication Date(Web):19 Jun 2015
DOI:10.1039/C5CE00909J
Transition metal (TM) cations and clusters have been widely used to functionalize polyoxometalates (POMs) of tungsten, molybdenum and vanadium due to their acidic nature, which made them compatible with addendum TM cations. Together with the good understanding of their solution behavior, a number of TM-based POMs have been achieved, which exhibited potential applications in many fields. Comparably, fewer polyoxoniobates (PONs) were obtained due to the poor understanding of their solution behavior, and they could only exist in strong alkaline aqueous solutions, where most of the TM cations precipitate because of the formation of hydroxide or oxide. Recently, TM cations were introduced into PONs by protection of chelate organic ligands or via selection of alkaline-soluble TM cations. Further, lacunary POMs, composed of early TM cations, were used as polydentate ligands to isolate PONs, and they make the PON clusters stably exist in acidic solutions. The acidic nature of tungstoniobate (W–Nb) clusters allowed acid-soluble TM cations to directly functionalize the Nb–W clusters. This highlight focuses on discussing the roles of TM centers in constructing PON-based materials, including TM-cluster-containing PONs, TM–organic group-decorating PONs and niobate clusters isolated by lacunary POMs. This systematic compilation of TM-PON studies will reveal a promising direction for further functionalization of PONs, and it will disclose a richer and more diverse set of structures in PON chemistry.
Co-reporter:Shuang Yao, Jing-Hui Yan, Hui Duan, Qian-Qian Jia, Zhi-Ming Zhang and En-Bo Wang
RSC Advances 2015 vol. 5(Issue 93) pp:76206-76210
Publication Date(Web):03 Sep 2015
DOI:10.1039/C5RA16325K
A new heterometallic 3d–4f cluster-containing polyoxotungstate KNa5{K2Dy2Cu2(H2O)8(SbW9O33)2}·17H2O (1) was designed and synthesized by reaction of the preformed large cluster [N(CH3)4]10Na12[Na2Sb8W36O132(H2O)4]·26H2O ({Sb8W36}), transition-metal (TM) and Ln3+ cations. Compound 1 is the first 3d–4f heterometallic cluster-containing sandwich-type tungstoantimonite obtained by partial decomposition of a preformed large cluster. Further, the sandwich-type polyoxoanion combines with two additional 4p cations resulting in a ring-like 3d–4f–4p cluster {K2Dy2Cu2(H2O)8}-containing polyoxotungstate. The sandwich polyoxoanion {K2Dy2Cu2(H2O)8(SbW9O33)2} was structurally similar to the well-known anion {K3Cu3(H2O)10(SbW9O33)2}, in which one alkali metal cation and one TM cation were both replaced by the rare earth metal cations. Furthermore, the 3d–4f–4p cluster-containing polyoxoanions were bridged by the K+ ion located at their central metal belt into a one-dimensional (1D) wavelike chain. An electrochemical study revealed that compound 1 exhibited electrocatalytic activity for reduction of the NO2− and O2, and a direct 4-electron electrochemical reduction process of O2 was achieved in 1-containing aqueous solution.
Co-reporter:Qing Lan, Zhi-Ming Zhang, Yang-Guang Li and En-Bo Wang
RSC Advances 2015 vol. 5(Issue 55) pp:44198-44203
Publication Date(Web):11 May 2015
DOI:10.1039/C5RA08262E
Two novel transition-metal-cluster-containing arsenicniobates, [Cu(en)2(H2O)][Cu(en)2]4{AsNb9V7O44}·8H2O (1) and [Cu(en)2(H2O)][Cu(en)2]4H{AsNb8V8O44}·11H2O (2), were designed and synthesized by reaction of K7HNb6O19·13H2O, Cu(Ac)2·H2O, Na2VO3, As2O3, and en molecules. Structural analysis revealed that compounds 1 and 2 contained the structural similar [AsNb9V7O44]10− and [AsNb8V8O44]11− polyoxoanions, respectively, which are obtained by inserting a {NbV7} or {V8} ring into the tetravacant polyoxoniobate [AsNb8O36]27−. Polyoxoanions in 1 and 2 could be regarded as the Keggin polyoxoniobates [AsNb9V3O40] or [AsNb8V4O40] capped by four VO5 units. The high-nuclear vanadium clusters were firstly introduced into the Keggin-type arsenicniobates. Further, polyoxoanions in 1 and 2 were connected by the metal–organic linkers into the 1D chain and 2D layer-like framework, respectively. Photocatalytic studies indicated that compounds 1 and 2 are both active for photocatalytic degradation of organic dye in aqueous solution, and they are stable and easily separated from the photocatalytic system for reuse as well.
Co-reporter:Jian-Sheng Li, Xiao-Jing Sang, Wei-Lin Chen, Rong-Lin Zhong, Ying Lu, Lan-Cui Zhang, Zhong-Min Su and En-Bo Wang
RSC Advances 2015 vol. 5(Issue 11) pp:8194-8198
Publication Date(Web):15 Dec 2014
DOI:10.1039/C4RA13005G
The photosensitive polyoxometalate (POM) [PW11O39RhCH2CO2H]5− was first introduced into the liquid crystal material through the encapsulation of dimethyldioctadecylammonium (DODA+). The theoretical calculation was performed to simulate the distribution of DODA+ around the POM anion. The surface photovoltage spectroscopy (SPS) result indicated that the hybrid exhibits the photovoltaic effect upon optical illumination and displays the character of a p-type material, which paves a new way for their potential application in the optoelectronics.
Co-reporter:Yuanhang Nie, Weilin Chen, Zhujun Liu, Enbo Wang
Inorganic Chemistry Communications 2015 Volume 61() pp:184-186
Publication Date(Web):November 2015
DOI:10.1016/j.inoche.2015.09.015
•We report three new complexes based on Keggin-typed POMs.•The complexes exhibit photocatalytic hydrogen evolution activities.•We firstly introduce the sacrificial electron donors into the structure POMs.A series of new complexes based on Keggin-type polyoxoanions (HTEA)2{[Na(TEA)2]H[SiW12O40]}∙5H2O (1), (HTEA)2{[Na(TEA)2][PW12O40]}∙4H2O (2) and (HTEA)2{[Na(TEA)2]H[GeW12O40]}∙4H2O (3) (TEA = triethanolamine) have been designed and synthesized. Single-crystal X-ray diffraction analyses reveal that compounds 1, 2 and 3 are isostructural, which exhibit the 1D chain structures consisting of Keggin-type polyoxoanions and {Na(TEA)2} linkers. Their structures were further characterized by XRD, IR spectroscopy, UV spectroscopy, elemental analyses, and thermogravimetric analysis. Moreover, compounds 1–3 present good the photocatalytic hydrogen evolution activities, which may be ascribed to the introduction of the sacrificial electron donors TEA to their structures, further, their photocatalytic hydrogen evolution activities are compared with its homologous Keggin-type heteropolyacid to verify the effect of TEA.The conventional photocatalytic system for hydrogen evolution requires both catalyst and sacrificial electron donor. Here, we firstly introduce the sacrificial electron donors into the structures of the POM anions and synthesize 3 new complexes. Their photocatalytic hydrogen evolution activities were compared with its homologous Keggin-type heteropolyacid, which demonstrate that the introduction of TEA can improve the photocatalytic activity.
Co-reporter:Li-na Hao, Ying Lu, Zhen-Zhen He, Zhu-jun Liu, Enbo Wang
Inorganic Chemistry Communications 2015 Volume 55() pp:88-91
Publication Date(Web):May 2015
DOI:10.1016/j.inoche.2015.03.026
•1 represents a rare example of homometallic salen-based MOFs.•The synthesis method is simplified to one step without the pre-metalation process.•The fluorescence spectra prove the influence of structure on the property.Two new homometallic coordination polymers 1 and 2 have been prepared by the directly one-step hydrothermal reactions of a carboxylate-functionalized salen ligand with Zn(II) and Co(II) ions, respectively. 1 exhibits a 3D open framework built by [Zn4(μ4-O)(carboxylate)8] units and double Zn-salen ligands, while 2 shows a 1D chain structure constructed by cobalt ions and the ligand derived from the hydrolysis to one CN bond of salen ligand. The preliminary fluorescence measurements of 1–2 show the influence of structure on the property.Two new homometallic coordination polymers 1 and 2 have been prepared by the directly one-step hydrothermal reactions of a carboxylate-functionalized salen ligand with Zn(II) and Co(II) ions, respectively. 1 exhibits a 3D open framework, while 2 shows a 1D chain structure derived from the hydrolysis of salen ligand.
Co-reporter:Anqi Mu, Jiansheng Li, Weilin Chen, Xiaojing Sang, ZhongMin Su, Enbo Wang
Inorganic Chemistry Communications 2015 Volume 55() pp:149-152
Publication Date(Web):May 2015
DOI:10.1016/j.inoche.2015.03.032
•P2Mo18 was introduced into the supercapacitor electrode for the first time.•The AC/P2Mo18 composite material improves the specific capacitance of primitive AC.•An AC/P2Mo18 electrode exhibits a remarkable rate capability (89%).A supercapacitor electrode assembled from activated carbon (AC) and (NH4)6[P2Mo18O62]·14.2H2O (P2Mo18) was fabricated for the first time, and showed remarkable electrochemical performance ascribed to the synergy of the double layer capacitance of AC and the pseudocapacitance of P2Mo18. The investigations indicate that the AC/P2Mo18 electrode exhibits a specific capacitance of 275 F g− 1 at a high current density of 6 A g− 1, which is substantially larger than the 182 F g− 1 of the AC electrode. In addition, the AC/P2Mo18 electrode possesses a remarkable rate capability (89%) when the current density is increased from 2 to 6 A g− 1.An AC/P2Mo18 composite material exhibiting a higher specific capacitance (275 F g− 1) than an AC electrode (182 F g− 1) at a high current density of 6 A g− 1 and possessing a remarkable rate capability (89%) when the current density increased from 2 to 6 A g− 1 has been introduced into a supercapacitor electrode for the first time.
Co-reporter:Xiao-Jing Sang, Jian-Sheng Li, Lan-Cui Zhang, Zai-Ming Zhu, Wei-Lin Chen, Yang-Guang Li, Zhong-Min Su and En-Bo Wang
Chemical Communications 2014 vol. 50(Issue 93) pp:14678-14681
Publication Date(Web):08 Oct 2014
DOI:10.1039/C4CC06211F
Two novel open-chain carboxyethyltin decorated sandwich-type germanotungstates have been successfully synthesized. They could markedly increase the electrocatalytic activity of single-walled carbon nanotubes toward triiodide reduction when assembled into composite electrodes, which have shown a conversion efficiency of 6.32% that is comparable to that of Pt electrodes (6.29%) when used as counter electrodes in dye-sensitized solar cells.
Co-reporter:Jian-Qiang Shen, Ying Zhang, Zhi-Ming Zhang, Yang-Guang Li, Yan-Qing Gao and En-Bo Wang
Chemical Communications 2014 vol. 50(Issue 45) pp:6017-6019
Publication Date(Web):17 Apr 2014
DOI:10.1039/C3CC49245A
Two phosphoniobate-based 3D frameworks were firstly constructed using the hexa-capped Keggin polyoxoniobates [PNb12O40(VO)6]3− and copper cations. Photocatalytic studies indicated that the hybrid materials exhibit photocatalytic hydrogen evolution activity.
Co-reporter:Xiaojing Sang, Jiansheng Li, Lancui Zhang, Zanjiao Wang, Weilin Chen, Zaiming Zhu, Zhongmin Su, and Enbo Wang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 10) pp:7876
Publication Date(Web):April 23, 2014
DOI:10.1021/am501192f
A novel sandwich-type germanotungstate [C(NH2)3]10[Mn2{Sn(CH2)2COOH}2(B-α-GeW9O34)2]·8H2O (1) represents the first single crystalline polyoxometalate (POM) functionalized by open chain carboxyethyltin, which was designed and synthesized in aqueous solution and applied to a dye-sensitized solar cell (DSSC) for the first time. Its photosensitivity was explored through a fluorescence spectrum (FL), surface photovoltage spectrum (SPV), electrochemical method, and solid diffuse spectrum. 1 displays the primary features of sensitizers in DSSCs, and the efficiency of the solar cell is 0.22%. Delightedly, when 1 was employed to assemble a cosensitized solar cell configuration by preparing a 1-doped TiO2 electrode and additionally adsorbing N719 dyes, a considerably improved efficiency was achieved through increasing spectral absorption and accelerating electron transport, which is 19.4% higher than that of single N719 sensitization. This result opens up a new way to position different dyes on a single TiO2 film for cosensitization.Keywords: carboxyethyltin; dye-sensitized solar cell; photosensitivity; polyoxometalate; TiO2;
Co-reporter:Ying Zhang, Jian-Qiang Shen, Li-Hua Zheng, Zhi-Ming Zhang, Yu-Xin Li, and En-Bo Wang
Crystal Growth & Design 2014 Volume 14(Issue 1) pp:110-116
Publication Date(Web):November 15, 2013
DOI:10.1021/cg401227g
Four novel heteropolyoxonibate-based inorganic–organic hybrids {Cu(en)2}6{GeNb12VIV2O42}·20H2O (1), {Cu(en)2}3K2Na4{GeNb12VIV2O42}·23H2O (2), {Cu(en)2}6{SiNb12VIV2O42}·18H2O (3), and {Cu(en)2}3K2Na4{SiNb12VIV2O42}·19H2O (4) (en = ethanediamine), composed of polyoxoanions [TNb12O40]16– (T = Si and Ge) and [Cu(en)2]2+ building blocks, were successfully synthesized under hydrothermal conditions by reaction of K7HNb6O19·13H2O, Cu(Ac)2·3H2O, Na2VO3, Na2SiO3, or GeO2 and en molecules. Polyoxoanion [TNb12VIV2O42]12– (T = Si and Ge) can be best described as a α-Keggin core [TNb12O40] with two [VO] units capping on its two “opened windows”. Compounds 1 and 3 are both composed of the bicapped heteropolyoxonibate core surrounded by a shell consisting of twelve [Cu(en)2]2+ groups, which represent a promising structural model toward core–shell nanostructures. Compounds 2 and 4 are also composed of a bicapped polyoxoanion [TNb12VIV2O42]12– (T = Si, Ge) decorated by three metal–organic fragments [Cu(en)2]2+, forming a trisupporting polyoxoanion {[Cu(en)2]3[TNb12O42VIV2]}6–. Antitumor, electrochemical study, and UV–vis spectra indicate that compounds 1–4 exhibit effective antitumor activity against SGC7901 cells and HepG2 cells and could keep the structural integrity in this process.
Co-reporter:Yan-Qing Gao, Zhi-Ming Zhang, Jian-Qiang Shen, Yue Jia, Zhu-Jun Liu and En-Bo Wang
CrystEngComm 2014 vol. 16(Issue 29) pp:6784-6789
Publication Date(Web):27 May 2014
DOI:10.1039/C4CE00536H
Two new hexavacant germanomolybdates, (H2enMe)3K2[Ge2Mo16O58]·4H3O·9H2O (1) (enMe = 1,2-propanediamine) and Na12[Ge2Mo16O58]·30H2O (2), were synthesized through the conventional aqueous method and characterized by X-ray crystallography, elemental analysis, IR spectra and thermogravimetry (TG) analysis. The polyoxoanions in compounds 1 and 2 contain two trivacant Keggin {β-A-GeMo9O34} units fused together by two {MoO6} octahedra. This structural type is different from that of the well-known basic structural types and rarely observed in the POM chemistry. Further, DODACl was used as the surfactant to encapsulate the hexavacant polyoxoanion, resulting in the surfactant-encapsulated cluster (SEC) [DODA]12[Ge2Mo16O58]·16H2O (SEC-Mo16). Polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and transmission electron microscopy (TEM) revealed that SEC-Mo16 exhibits characteristic thermotropic liquid crystal properties.
Co-reporter:Yue Liang, Zhi-Ming Zhang, Zhu-Jun Liu, Ying Zhang, Jun Zhang and En-Bo Wang
CrystEngComm 2014 vol. 16(Issue 6) pp:1187-1191
Publication Date(Web):02 Dec 2013
DOI:10.1039/C3CE41278D
A novel pseudosandwich-type polyoxovanadate, CoII2{(VO2)CoIII(CoIIIL)2[V5O16]2}·23H2O (1) (L = 1,3-propanediamine, 1,3-pda), has been isolated using a conventional aqueous solution method and characterized by elemental analysis, IR spectrum, thermal gravimetric analysis and magnetism. Single crystal X-ray diffraction analyses indicate that polyoxoanion 1 is composed of a {CoIII3(1,3-pda)2} cluster coordinated by two lacunary Lindqvist polyoxovanadates [V5O18]. Polyoxoanion 1 contains three CoIII centers in its central metal set, which was first observed in the polyoxometalate chemistry. Further, two CoIII ions in polyoxoanion 1 are functionalized by two 1,3-pda ligands resulting in a pseudosandwich-type polyoxovanadate-based organic–inorganic hybrid material, which represents the first pseudosandwich-type polyoxovanadate decorated by two 1,3-pda ligands.
Co-reporter:Chun-Chen Yuan, Shi-Ming Wang, Wei-Lin Chen, Lin Liu, Chao Qin, Zhong-Min Su and En-Bo Wang
Dalton Transactions 2014 vol. 43(Issue 4) pp:1493-1497
Publication Date(Web):12 Nov 2013
DOI:10.1039/C3DT52676C
Two Anderson-type heteropolyanion-supported copper phenanthroline redox couples have been successfully introduced into dye-sensitized solar cells, which can significantly increase the short-circuit photocurrent, open-circuit voltage and the conversion efficiency by 2.2 times, 26.8% and 3.93 times respectively, compared to the pristine copper phenanthroline redox couple.
Co-reporter:Hong-Li Wu, Zhi-Ming Zhang, Yang-Guang Li and En-Bo Wang
RSC Advances 2014 vol. 4(Issue 82) pp:43806-43810
Publication Date(Web):28 Aug 2014
DOI:10.1039/C4RA07525K
Dimethyldioctadecylammonium (DODA+) was used as a surfactant to react with the high-nuclear transition-metal cluster-containing polyoxometalate K5Na11[Ni9(OH)3(H2O)6(HPO4)2(PW9O34)3]·52H2O (POM-1), resulting in an organic–inorganic hybrid complex (DODA)16[Ni9(OH)3(H2O)6(HPO4)2(PW9O34)3]·36H2O (SEP-1), which exhibits characteristic thermotropic liquid crystalline behavior. Here, the high-nuclear transition-metal cluster-substituted polyoxoanions were firstly introduced into liquid crystalline materials. The chemical composition of the obtained SEP-1 was determined by IR spectra, elemental analysis, and thermogravimetric (TG) analysis. Also, polarized optical microscopy, differential scanning calorimetry (DSC), and variable temperature X-ray diffraction (VT-XRD) were performed on SEP-1 to confirm its thermotropic liquid crystalline behavior.
Co-reporter:Shi-Ming Wang, Lin Liu, Wei-Lin Chen, Zhong-Min Su, En-Bo Wang, and Chao Li
Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 1) pp:150-156
Publication Date(Web):2017-2-22
DOI:10.1021/ie402074c
A new H3PW12O40 (PW12)-based interfacial layer for dye-sensitized solar cells (DSSCs) has been fabricated by the LBL method. The features of the interfacial layer were tested by IR and UV–vis spectroscopies and AFM. The cells were systemically tested by the photocurrent–voltage (J–V) curve, dark-current measurement, open-circuit voltage decay (OCVD), and monochromatic incident photon-to-photocurrent conversion efficiency (IPCE) techniques. The PW12-based interfacial layer was found to accelerate electron transfer and retard recombination, eventually leading to an efficient increase in energy conversion efficiency. The investigations indicate that the energy conversion efficiency of a (PW12/TiO2)3-based DSSC is significantly enhanced by 54% at 100 mW cm–2 compared with a DSSC with no treatment and by 20% compared with a TiCl4-treatment DSSC. Polyoxometalate was first introduced into the interfacial layer in modifying the photoanode to accelerate electron transfer and retard recombination to improve DSSC efficiency in this work.
Co-reporter:Tingting Zhang, Ying Lu, Zhiming Zhang, Qing Lan, Ding Liu, Enbo Wang
Inorganica Chimica Acta 2014 Volume 411() pp:128-133
Publication Date(Web):24 February 2014
DOI:10.1016/j.ica.2013.11.041
•The 3D framework of 1 possesses both hydrophobic and hydrophilic channels.•1 can reversibly transform to 2 upon SCSC process.•Both 1 and 2 were indicated the presence antiferromagnetic interactions.A new metal–organic framework (MOF) [Cu5(pz)2(μ3-OH)2(bdc)2(Hbdc)2]·8H2O (1) possessing both hydrophobic and hydrophilic channels has been prepared by two synthetic methods which have subtle differences. Interestingly, 1 can reversibly transform to a layered coordination polymer Na{[(Cu3(pz)3(μ3-OH)]2(bdc)2(Hbdc)}·DMF·21H2O (2) upon a single-crystal to single crystal (SCSC) process. 1 exhibits an 8-connected three-dimensional (3D) framework constructed by pentanuclear copper units and bdc linkers, while 2 shows a two-dimensional (2D) network built by triangular trinuclear copper units and bdc linkers. Furthermore, the magnetic properties of both 1 and 2 have been studied.There are two methods to implement the metal–organic framework 1 possessing both hydrophobic and hydrophilic channels, but only one way can achieve the reversible single-crystal to single-crystal transformation from 1 to a layered coordination polymer 2, which cannot be accomplished directly.
Co-reporter:Yue Jia, Jun Zhang, Zhi-Ming Zhang, Qiu-Yu Li, En-Bo Wang
Inorganic Chemistry Communications 2014 Volume 43() pp:5-9
Publication Date(Web):May 2014
DOI:10.1016/j.inoche.2014.01.015
•The Waugh- and Silverton-type-based thermotropic liquid crystal materials.•The metal-centered polyoxometalates were introduced into the POM/surfactant system•The thermotropic liquid crystal materials exhibit typical smectic mesomorphic behaviors.Waugh- and Silverton-type polyoxometalates (POMs) K3(NH4)3[MnMo9O32] and H8[CeMo12O42] are enwrapped by dioctadecyldimethylammonium (DODA+) forming the surfactant-encapsulated POMs (SEPs) (DODA)6[MnMo9O32]·16H2O (DODA-MnMo9) and (DODA)8[CeMo12O42]·9H2O (DODA-CeMo12), which exhibit typical thermotropic liquid-crystalline properties. Here, the Waugh- and Silverton-type polyoxoanions centered by metal cation were firstly introduced into liquid crystal materials. The chemical composition of these SEP complexes was determined by IR spectra, elemental analysis and TG analysis. Also, the polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and transmission electron microscopes (TEM) were performed to characterize their liquid-crystalline behavior.The metal-centered polyoxometalates were introduced into the POM/surfactant system resulting in the organic–inorganic hybrid materials with characteristic thermotropic liquid-crystalline behavior.Figure optionsDownload full-size imageDownload as PowerPoint slide
Co-reporter:Chun-Chen Yuan, Shi-Ming Wang, Wei-Lin Chen, Lin Liu, Zhi-Ming Zhang, Ying Lu, Zhong-Min Su, Si-Wen Zhang, En-Bo Wang
Inorganic Chemistry Communications 2014 Volume 46() pp:89-93
Publication Date(Web):August 2014
DOI:10.1016/j.inoche.2014.05.023
•This is the first report of a pure-inorganic-cobalt-compound redox couple for DSSCs.•Two Keggin-type POMs have been employed as a redox couple in DSSCs.•The redox potential of the {CoII/IIIW12} couple matches with dye and TiO2.•The {CoII/IIIW12} redox couple shows weak absorption in the visible light region.Two Keggin-type polyoxometalates [K6CoIIW12O40 (denoted as {CoIIW12}) and K5CoIIIW12O40 (denoted as {CoIIIW12})] were firstly employed as the redox couple in dye-sensitized solar cells. Photocurrent density–photovoltage curves, cyclic voltammetry curves, photocurrent action spectra and UV–vis spectra demonstrated that {CoIIW12} and {CoIIIW12} displayed weak absorption in the visible light region, potential matching with dye and TiO2 conducting band, and significant conversion efficiency.Two Keggin-type polyoxometalates have been successfully employed as the redox couple in dye-sensitized solar cells for the first time, which achieved relatively high values of open circuit voltage (651 mV) and fill factor (0.549).
Co-reporter:Yi-Zhen Chen, Zhu-Jun Liu, Zhi-Ming Zhang, Huan-Yu Zhou, Xiao-Tao Zheng, En-Bo Wang
Inorganic Chemistry Communications 2014 Volume 46() pp:155-158
Publication Date(Web):August 2014
DOI:10.1016/j.inoche.2014.05.012
•A group of heterometal-substituted compounds•{LnMn4} appended cubanes•Tetravacant polyoxometalate {SiW8O31}-based sandwich polyoxotungstateExploration of the reactivity of the versatile polyoxometalate precursor [β2-SiW11O39]8 − with lanthanide cations, transition-metal cations, carbonate, and morpholine, afforded a group of new appended cubanes {LnMnIII4} (Ln = HoIII, TmIII, YbIII, SmIII, GdIII, ErIII and CeIV). The appended cubanes {LnMnIII4} were encapsulated by two inorganic polyoxometalate ligands, resulting in a series of heterometallic cluster-based sandwich-type compounds: K10Na3[{LnIIIMnIII4(μ3-O)2(μ2-OH)2(H2O)(CO3)}(β-SiW8O31)2]·xH2O (Ln = HoIII, x = 24 for 1; Ln = TmIII, x = 22 for 2; Ln = YbIII, x = 21 for 3); K7Na6[{LnIIIMnIII4(μ3-O)2(μ2-OH)2(H2O)(CO3)}(β-SiW8O31)2]·xH2O (Ln = SmIII, x = 22 for 4; Ln = GdIII, x = 20 for 5; Ln = ErIII, x = 22 for 6) and K7Na5[{CeIVMnIII4(μ3-O)2(μ2-OH)2(H2O)(CO3)}(β-SiW8O31)2]·24H2O (7), which were characterized by single-crystal X-ray diffraction analyses, IR spectroscopy, and thermal gravimetric analysis. Electrocatalytic study reveals that these compounds exhibited the activity of electrocatalytic reduction of sodium nitrite.A series of Ln cations were introduced into the reaction system of [β2-SiW11O39]8 -, transition metal ions, organic ligand and CO32 − resulting in a group of {LnMnIII4} cubanes stabilized by inorganic polyoxometalate ligands.
Co-reporter:Li Chen, Xiao-Jing Sang, Jian-Sheng Li, Chun-Hui Shan, Wei-Lin Chen, Zhong-Min Su, En-Bo Wang
Inorganic Chemistry Communications 2014 Volume 47() pp:138-143
Publication Date(Web):September 2014
DOI:10.1016/j.inoche.2014.07.019
•{P2Mo18VI} and {P2Mo2VMo16VI} were first introduced into photoanode of DSSCs.•Both heteropolyacid and heteropoly blue can improve the performance of DSSCs.•{P2Mo18VI} and {P2Mo2VMo16VI} could both suppress the dark current in DSSCs.•{P2Mo18VI} and {P2Mo2VMo16VI} could both increase the electron lifetime in DSSCs.•Heteropoly blue can be a potential electron attractor for photovoltaic application.Dawson-type heteropolyacid {P2Mo18VI} and its two-electron heteropoly blue {P2Mo2VMo16VI}-doped TiO2 composites have been successfully prepared by a simple sol–gel method and introduced into the photoanode of dye-sensitized solar cells (DSSCs), which results in a significant performance enhancement of DSSCs. The electrochemical impedance spectroscopy (EIS) and open-circuit voltage decay (OCVD) curve were employed to investigate the electron transport and carrier recombination behavior in DSSCs. The results show that doping with {P2Mo18VI} and {P2Mo2VMo16VI} could both suppress the dark current and increase the electron lifetime in DSSCs. The performance of DSSCs with both {P2Mo18VI}-doped and {P2Mo2VMo16VI}-doped photoanodes is better than that with pure P25 photoanodes and the overall conversion efficiency was improved by 24.48% and 17.19%, respectively.Dawson-type heteropolyacid {P2Mo18VI} and its two-electron heteropoly blue {P2Mo2VMo16VI}-doped TiO2 composites have been introduced into the photoanode of DSSCs for the first time, which could both suppress the dark current and increase the electron lifetime in DSSCs.
Co-reporter:Chun-Hui Shan, Xiao-Jing Sang, Hong Zhang, Jian-Sheng Li, Wei-Lin Chen, Zhong-Min Su, En-Bo Wang
Inorganic Chemistry Communications 2014 50() pp: 13-16
Publication Date(Web):
DOI:10.1016/j.inoche.2014.10.004
Co-reporter:Ai-Xue Yan;Dr. Shuang Yao; Yang-Guang Li;Dr. Zhi-Ming Zhang;Dr. Ying Lu;Dr. Wei-Lin Chen; En-Bo Wang
Chemistry - A European Journal 2014 Volume 20( Issue 23) pp:6927-6933
Publication Date(Web):
DOI:10.1002/chem.201400175
Abstract
Various polyoxometalates (POMs) were successfully immobilized to the mesoporous coordination polymer MIL-101 resulting in a series of POM–MOF composite materials POM@MIL-101 (POM=K4PW11VO40, H3PW12O40, K4SiW12O40). These materials were synthesized by a simple one-pot reaction of Keggin POMs, tetramethylammonium hydroxide (TMAH), terephthalic acid (H2bdc), and Cr3+ ions. XRD, FTIR, thermogravimetric analyses (TG), inductively coupled plasma (ICP) spectrometry, and energy-dispersive X-ray spectroscopy (EDX) collectively confirmed the successful combination of POMs and the porous framework. Further, these composites POM@MIL-101 with different loading of POMs were achieved by variation of the POM dosage. Notably, the uptake capacity of MIL-101 towards organic pollutants in aqueous solution was significantly improved by immobilization of hydrophilic POMs into cages of MIL-101. An uptake capacity of 371 mg g−1, comparable to that of the graphene oxide sponges, and much higher than that of the commercial activated carbon, was achieved at room temperature in 5 min when dipping 20 mg PW11V@MIL-101 in the methylene blue (MB) solution (100 mL of 100 mg L−1 MB solution). Further study revealed that the POM@MIL-101 composite materials not only exhibited a fast adsorption rate towards dye molecules, but also possessed of selective adsorption ability of the cationic dyes in wastewater. For example, the adsorption efficiency of PW11V@MIL-101 (10 mg) towards MB (100 mL of 10 mg L−1) could reach 98 % in the initial 5 min, and it could capture MB dye molecules from the binary mixture of the MB and MO with similar size. Also, the POM@MIL-101 materials could be readily recycled and reused, and no POM leached in the dye adsorption process.
Co-reporter:Jian-Qiang Shen;Dr. Qiong Wu;Ying Zhang;Dr. Zhi-Ming Zhang; Yang-Guang Li;Dr. Ying Lu; En-Bo Wang
Chemistry - A European Journal 2014 Volume 20( Issue 10) pp:2840-2848
Publication Date(Web):
DOI:10.1002/chem.201303995
Abstract
Reactions of hexaniobate with vanadate in the presence of Ni2+, Zn2+, or Cu2+ have furnished three high-nuclear vanadium cluster-substituted heteropolyoxoniobates (HPNs): {Ni(en)3}5H{VVNb8VIV8O44}⋅9 H2O (1), (H2en)Na2[{Zn(en)2(Hen)}{Zn(en)2(H2O)}2{PNb8VIV8O44}]⋅11 H2O (2), and Na{Cu(en)2}3{[Cu(en)2]2[PNb8VIV8O44]}⋅11 H2O (3) (en=1,2-diaminoethane). Their structures have been determined and characterized by single-crystal X-ray diffraction analysis, thermogravimetric analysis (TGA), and elemental analysis. Structural analysis has revealed that compounds 1–3 contain similar {V8}-substituted [XVNb8VIV8O44]11− (X=P, V) clusters, obtained by inserting a {V8} ring into tetravacant HPN [XNb8O36]27−. To the best of our knowledge, compounds 1–3 represent the first high-nuclear vanadium cluster-substituted HPNs, and compound 1 is the largest vanadoniobate cluster yet obtained in HPN chemistry. Nickel and zinc cations have been introduced into HPNs for the first time, which might promise a more diverse set of structures in this family. Antitumor studies have indicated that compounds 1 and 2 exhibit high activity against human gastric cancer SGC-7901 cells, SC-1680 cells, and MG-63 cells.
Co-reporter:Jun Zhang;Qing Lan;Zhi-Ming Zhang;Zhu-Jun Liu;Yue Liang
Journal of Cluster Science 2014 Volume 25( Issue 1) pp:253-259
Publication Date(Web):2014 January
DOI:10.1007/s10876-013-0634-8
A new crown inorganic–organic hybrid material composed of the Keggin polyoxometalates and transition metal-amino acid coordination complexes, K2{[KCu4(gly)4(OH)2(H2O)2Cl][PW12O40]}2·19H2O (1), was synthesized and characterized by elemental analysis, IR spectroscopy, TG analysis and single crystal X-ray diffraction. Compound 1 possesses of a 1D chain structure with a crown-type monomer, which is built up from [PW12O40]3− building blocks and tetranuclear [KCu4(gly)4(OH)2(H2O)2Cl] rings. The [KCu4(gly)4(OH)2(H2O)2Cl] ring consists of four Cu2+ ions and four gly ligands, which exhibits the crown ether feature binding a potassium ion in its center. Further, two [KCu4(gly)4(OH)2(H2O)2Cl] rings linked two Keggin polyoxoanions [PW12O40]3− into crown inorganic–organic hybrid material. Magnetic study shows the existence of ferromagnetic interactions in compound 1.
Co-reporter:Tian-Zhan Zhang;Dr. Shuang Yao;Dr. Zhi-Ming Zhang;Ying Lu; Yang-Guang Li; En-Bo Wang
ChemPlusChem 2014 Volume 79( Issue 8) pp:1153-1158
Publication Date(Web):
DOI:10.1002/cplu.201402094
Abstract
Two new transition-metal (TM)-containing polytantalotungstates, CsNa2H[Cu(bpy)(H2O)3]3{[Cu(bpy)2]2[Cu(bpy)(H2O)2]3[Ta4O6(SiW9Ta3O40)4]}⋅17 H2O (1) and K4Na4H4[Ta4O6(SiW9Ta3O40)4][Cu(apy)(H2O)2]4⋅42 H2O (2) (bpy=2,2′-bipyridine, apy=3-aminopyridine), have been synthesised under hydrothermal conditions. Both compounds 1 and 2 were determined and characterised by single-crystal X-ray diffraction analysis, thermogravimetric analysis, IR spectroscopy, UV/Vis spectroscopy and elemental analysis. Compounds 1 and 2 contain W/Ta mixed-addendum nanoclusters decorated by TM–organic fragments. Compounds 1 and 2 are the first TM-containing polytantalotungstates promise a more diverse set of structures of the polytantalotungstate family. The obtained materials can harvest a wide spectrum of solar light, from UV to near-infrared (NIR) wavelength. Photocatalytic study revealed that compounds 1 and 2 exhibited UV- and visible-light-driven photocatalytic water splitting activity. Compound 1 could also be used as a catalyst for the photocatalytic decomposition of 2,4-dichlorophenol in water with NIR-light irradiation. This is the first NIR photocatalyst obtained in polyoxometalate chemistry.
Co-reporter:Yue Jia, Hua-Qiao Tan, Zhi-Ming Zhang and En-Bo Wang
Journal of Materials Chemistry A 2013 vol. 1(Issue 23) pp:3681-3685
Publication Date(Web):11 Apr 2013
DOI:10.1039/C3TC30179F
By ion metathesis reactions, the dimethyldioctadecylammonium (DODA+) was used as the surfactant to encapsulate organic–inorganic hybrid polyoxometalates (POMs) (NH4)6{Mo2VO4[(Mo2VIO6)NH3CH2CH2CH2C(O)(PO3)2]2}·10H2O (POM-1) and (NH4)8{Mo2VO4[(Mo2VIO6)CH3C(O)(PO3)2]2}·14H2O (POM-2), resulting in two surfactant-encapsulated clusters (SECs) with characteristic thermotropic liquid-crystalline behavior. The chemical composition of the obtained SECs was determined by IR spectra, elemental analysis, TG analysis and NMR spectra. Also, polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and TEM of the samples were also performed, which revealed that both SECs show thermotropic liquid crystal behavior.
Co-reporter:Ge Jin, Shi-Ming Wang, Wei-Lin Chen, Chao Qin, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2013 vol. 1(Issue 23) pp:6727-6730
Publication Date(Web):26 Apr 2013
DOI:10.1039/C3TA10814G
A spherical keplerate {W72V30} acts as the electron acceptor in a photovoltaic system for the first time. It is a promising alternative electron acceptor to the traditional electron acceptor fullerene (C60). A water-soluble PPV derivative (P2) was chosen as the electron donor. This work represents a promising strategy in designing polymer photovoltaic devices.
Co-reporter:Shi-Ming Wang, Lin Liu, Wei-Lin Chen, Zhi-Ming Zhang, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2013 vol. 1(Issue 2) pp:216-220
Publication Date(Web):15 Nov 2012
DOI:10.1039/C2TA00486K
We explore a new method to prepare polyoxometalate-based electrochromic (EC) smart windows. It is a simple and low cost process to prepare EC films by a solution-based electrodeposition method. The polyoxometalate-based EC smart windows exhibit high transparency in the bleached state, good optical contrast, long durability, and high coloration efficiency.
Co-reporter:Ding Liu, Ying Lu, Hua-Qiao Tan, Wei-Lin Chen, Zhi-Ming Zhang, Yang-Guang Li and En-Bo Wang
Chemical Communications 2013 vol. 49(Issue 35) pp:3673-3675
Publication Date(Web):15 Mar 2013
DOI:10.1039/C3CC40990B
Purely inorganic porous frameworks using catalytically active [MnV13O38]7− clusters as nodes and rare earth ions as linkers have been successfully prepared. The POM-based porous framework is a kind of multifunctional material, which exhibits selective adsorption behavior and remarkable catalytic activity for the heterogeneous oxidation of sulfides.
Co-reporter:Zhi-Ming Zhang, Shuang Yao, Yang-Guang Li, Hai-Hong Wu, Yong-Hui Wang, Mathieu Rouzières, Rodolphe Clérac, Zhong-Min Su and En-Bo Wang
Chemical Communications 2013 vol. 49(Issue 25) pp:2515-2517
Publication Date(Web):06 Feb 2013
DOI:10.1039/C3CC38981B
A polyoxometalate (POM)-based {MnIV2MnIII6MnII4} complex with single-molecule magnet (SMM) behaviour was prepared, exhibiting the largest known Mn nuclearity and the most Mn valence states in the POM-based SMM family.
Co-reporter:Shi-Ming Wang, Lin Liu, Wei-Lin Chen, En-Bo Wang
Electrochimica Acta 2013 Volume 113() pp:240-247
Publication Date(Web):15 December 2013
DOI:10.1016/j.electacta.2013.09.048
•Polyoxometalates-based smart windows have been fabricated using electrodeposition method.•The slight adjusting of the structure of the polyoxometalates influences electrochromic properties of the smart windows greatly.•The electrochromic smart windows show high performance in both visible and near-infrared region.•The maximum optical contrast of 93.1% achieved under low applied potential.Polyoxometalates (POMs) are a kind of metal oxide nanoclusters with excellent electrical properties, which have proved to be an excellent candidate for electrochromism (EC) materials. In this paper, we present a better performance POMs-based EC material on the TiO2 substrate through adjusting the structure of the Well-Dawson type POMs with the electrodeposition method, which can overcome the high cost of the traditional methods such as vacuum evaporation or sputtering. The performance of the EC smart windows was fully tested. The maximum optical contrast for the K10[P2W17O61]·20H2O (P2W17)-based EC smart window is 93.1% at the wavelength of 620 nm and for the K6[P2W18O62]·14H2O (P2W18)-based EC smart window is 48.7% at 646 nm. The coloration time extracted for a 90% transmittance for the P2W17-based EC smart window is 0.9 s and for the P2W18-based smart window is 0.97 s; the coloration efficiency for the P2W17-based EC smart window is 205.3 cm2 C−1 and the P2W18-based smart window is 176.8 cm2 C−1. Both of the P2W17- and P2W18-based EC smart windows have the feature of remarkable durability over 1000 cycles. The P2W17-based smart window has larger optical contrast and higher coloration efficiency than the P2W18-based smart window. More significantly, the near-infrared behavior of the P2W17 under different applied potentials was recorded for the first time by using the smart window. We believe the performance of the P2W17-based smart window is the state-of-the-art among the POMs-based EC smart windows.High performance polyoxometalates (POMs)-based electrochromic smart windows have been fabricated. By adjusting the structure of the Dawson-type POM, it can be found that mono-vacant lacunary Dawson-type POM-based smart window has remarkable performance. For example, the maximum optical contrast 93.1% at the wavelength of 620 nm; the coloration time extracted for a 90% transmittance is 0.90 s; and the coloration efficiency is 205.3 cm2 C−1. The near-infrared electrochromic behaviors of the POMs have been investigated for the first time.
Co-reporter:Tian-Zhan Zhang, Zhi-Ming Zhang, Ying Lu, Hai Fu and En-Bo Wang
CrystEngComm 2013 vol. 15(Issue 3) pp:459-462
Publication Date(Web):12 Nov 2012
DOI:10.1039/C2CE26400E
The sodalite-type metal–organic framework constructed from heterometallic alkali metal/V secondary building units with large internal cavity was firstly obtained. The organic amine cations within the channels can be replaced by transition metal ions through a cation exchange process, and subsequent gas adsorption measurements confirm the permanent porosity.
Co-reporter:Qing Lan, Jun Zhang, Zhi-Ming Zhang, Ying Lu and En-Bo Wang
Dalton Transactions 2013 vol. 42(Issue 47) pp:16602-16607
Publication Date(Web):10 Sep 2013
DOI:10.1039/C3DT51722E
Two new porous frameworks [Ni(bix)2][VW12O40]·(H2bix)·H2O (1) and [Co(bix)2][VW12O40]·(H2bix)·2H2O (2) (bix = 1,4-bis(imidazol-1-ylmethyl)-benzene) composed of Keggin polyoxometalates (POMs) and metal–organic coordination polymer sheets have been successfully obtained, and characterized by elemental analysis, IR spectra, thermal gravimetric analysis, and single crystal X-ray diffraction. Structural analysis reveals that the 2D metal–organic coordination polymer sheets in the two compounds are constructed from the transition-metal (TM) cations and the flexible N-donor ligand bix, which are further pillared by POM clusters into the 3D porous frameworks. Powder X-ray diffraction (PXRD) patterns of 1 indicate the structural integrity of the framework in aqueous solution with a wide pH range of 1 to 11, and in common organic solvents (methanol, ethanol and DMF). Photocatalytic studies indicate that compounds 1 and 2 are not only active photocatalysts for degradation of rhodamine B (RB), but very stable and easily separated from the photocatalytic system for reuse as well.
Co-reporter:Ding Liu, Ying Lu, Yang-Guang Li, Hua-Qiao Tan, Wei-Lin Chen, Zhi-Ming Zhang and En-Bo Wang
Dalton Transactions 2013 vol. 42(Issue 40) pp:14445-14453
Publication Date(Web):07 Aug 2013
DOI:10.1039/C3DT51250A
Three trimeric polyoxovanadate based on 1:13 anions [MnV13O38]7− with lanthanide cations Ln3+ (Ln = La, Ce and Nd) and pyridine-3-carboxylic acid: HK3{[Ln(H2O)4]6[MnV13O38]3(SO4)2}·3(C6H6NO2)·nH2O (Ln = La 1, Nd 3; n = 33 for 1, 20 for 3), H2.5K1.5{[Ce(H2O)4]6[MnV13O38]3(SO4)2}·3(C6H6NO2)·20.5H2O (2) (C6H5NO2 = pyridine-3-carboxylic acid) have been synthesized and characterized by elemental analysis, IR spectroscopy, UV spectroscopy, TG analysis, XPRD, electrochemical analyses, magnetism and single-crystal X-ray diffraction. Compounds 1–3 are isostructural and crystallized in the hexagonal system, space group P63/m. Compounds 1–3 contain an unusual trimeric polyoxoanion [{Ln2MnV13O38}3(SO4)2]7−, representing the first polyoxovanadate-based trimeric aggregate with rare earth ions. The electrochemical and electrocatalytic properties of the compounds have been investigated. Magnetic studies indicate that antiferromagnetic interactions exist in the compounds.
Co-reporter:Jian-Qiang Shen, Shuang Yao, Zhi-Ming Zhang, Hai-Hong Wu, Tian-Zhan Zhang and En-Bo Wang
Dalton Transactions 2013 vol. 42(Issue 16) pp:5812-5817
Publication Date(Web):31 Jan 2013
DOI:10.1039/C3DT32855D
An unprecedented organic–inorganic hybrid germanoniobate compound Na4[Cu(en)2(H2O)2]5[Na6Ge8Nb32O108H8(OH)4]·41H2O (1) was synthesized under the hydrothermal condition. In compound 1, the {Nb16} cage containing four {GeO4} tetrahedra in its internal cavity results in a heteropolyniobate anion [H4Ge4Nb16O54(OH)2]10− ({Ge4Nb16}), which is connected by a {Na6} cluster into the first germanoniobate-based sandwich-type structure. Further, the sandwich germanoniobates are connected by [Na2Cu(en)2O6H8] groups into a porous network with one dimensional channels along the a-axis. Photocatalytic study reveals that compound 1 exhibits good photocatalytic activity for the degradation of methylene blue.
Co-reporter:Shi-Ming Wang, Lin Liu, Wei-Lin Chen, En-Bo Wang and Zhong-Min Su
Dalton Transactions 2013 vol. 42(Issue 8) pp:2691-2695
Publication Date(Web):11 Dec 2012
DOI:10.1039/C2DT32403B
Polyoxometalate–TiO2 composites have been successfully introduced into the photoanode of dye-sensitized solar cells to reduce the recombination of the electrons, which results in a longer electron lifetime. The performance of the cells with the polyoxometalate-modified photoanode is better than the cell with a pure P25 photoanode. The effect of the polyoxometalate was studied by electrochemical impedance spectroscopy and open-circuit voltage decay measurement. The results show that the electron lifetime becomes longer following an increase in the amount of the polyoxometalate.
Co-reporter:Hai-Hong Wu, Shuang Yao, Zhi-Ming Zhang, Yang-Guang Li, You Song, Zhu-Jun Liu, Xin-Bao Han and En-Bo Wang
Dalton Transactions 2013 vol. 42(Issue 2) pp:342-346
Publication Date(Web):26 Oct 2012
DOI:10.1039/C2DT32318D
The heterometallic appended {MMnIII4} (M = Dy3+ and K+) cubanes were firstly trapped by two diamagnetic POM shells, which were robust enough to construct inorganic crystalline tubular materials. Magnetic study reveals the presence of a SMM-like slow magnetic relaxation feature in the heterometallic cluster-containing POM.
Co-reporter:Chunchen Yuan, Shuangshuang Guo, Shiming Wang, Lin Liu, Weilin Chen, and Enbo Wang
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 20) pp:6694-6703
Publication Date(Web):April 25, 2013
DOI:10.1021/ie302845z
A polyoxometalate (POM)-doped poly(3,4-ethylenedioxythiophene) (PEDOT) hybrid film counter electrode was successfully fabricated by electropolymerization in an environmentally friendly aqueous solution. The hybrid film presents a similar surface morphology to lotus leaf, the microstructure of which is a regularly distribution of mastoid shapes. As far as we know, it is the first time that POM-PEDOT hybrid film with mastoid morphology was fabricated. The application of the hybrid film counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) was studied for the first time, and the efficiency of DSSCs based on hybrid film CEs was almost as high as DSSCs with Pt CEs. FTIR results indicated that POM polyanions had already been dispersed into the PEDOT matrix. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization test results show that the electrocatalytic ability for I3– reduction of the hybrid film CE is comparable to that of a Pt CE. In addition, the SiW11–PEDOT hybrid film has good electrochemical stability.
Co-reporter:Shuang Yao;Jing-Hui Yan;Hui Duan;Zhi-Ming Zhang;Yang-Guang Li;Xin-Bao Han;Jian-Qiang Shen;Hai Fu
European Journal of Inorganic Chemistry 2013 Volume 2013( Issue 27) pp:4770-4774
Publication Date(Web):
DOI:10.1002/ejic.201300655
Abstract
Reactions of lacunary polyoxometalate (POM), transition-metal (TM), and lanthanide-metal (Ln) cations with the assistance of additional small organic molecules under hydrothermal conditions led to the formation of a group of metal–POM frameworks (MPFs) with nanospaces: [Cu(enMe)2]13{Ln(SiW11O39)2}2·xH2O [Ln = Ho3+ (compound 1), Dy3+ (compound 2), Eu3+ (compound 3), Er3+ (compound 4), Sm3+ (compound 5), Pr3+ (compound 6); x = 18 for 1, 5, 6; x = 20 for 2, 3, 4; enMe = 1,2-diaminopropane). Single-crystal X-ray diffraction analyses reveal that all the compounds are composed of two monovacant POMs, which are linked by one Ln3+ ion into a dimeric structure. The dimeric structure acts as an inorganic polydentate ligand coordinated with Cu2+ ions, which results in 3D MPFs with two channels. As the individual components integrated in the MPF materials posess fluorescent and magnetic properties, the luminescence properties and magnetic behavior of the resulting MPFs were measured.
Co-reporter:Ying Zhang, Xin-Bao Han, Zhi-Ming Zhang, Zhu-Jun Liu, En-Bo Wang
Chinese Chemical Letters 2013 Volume 24(Issue 7) pp:581-584
Publication Date(Web):July 2013
DOI:10.1016/j.cclet.2013.04.034
A {Ni7} cluster-substituted sandwich-type phosphotungstate Na10(NH4)4[{(B-a-PW9O34)Ni3(OH)(H2O)2(HAle)}2Ni]·22H2O (1) was synthesized using the conventional aqueous solution method. Compound 1 represents the first nickel-containing sandwich-type polyoxometalate functionalized by bisphosphonate ligands. Further, the sandwich-type polyoxoanions aggregated via the H-bonding interactions into a two-dimensional (2D) supramolecular framework.A {Ni7} cluster-containing sandwich-type phosphotungstate was obtained using the conventional aqueous method, which formed a 2D supramolecular structure via intermolecular H-bonding interactions.
Co-reporter:Jun Zhang, Wei-Lin Chen, En-Bo Wang
Inorganic Chemistry Communications 2013 Volume 38() pp:96-99
Publication Date(Web):December 2013
DOI:10.1016/j.inoche.2013.10.010
•For the first time, D–π–A type POMs were combined with TiO2;•The composite materials were synthesized through layer-by-layer method.•The POM@TiO2 showed excellent catalytic ability in treating organic pollutants.Donor–π-bridge–acceptor (D–π–A) type polyoxometalates (POMs) were self-assembled for the first time on the surface of titanium dioxide (TiO2) nanoparticles through the layer-by-layer (LBL) method. The obtained composite materials POM@TiO2 were characterized by Transmission electron microscopy (TEM), Fourier transform IR spectroscopy (FTIR), Raman spectrum and energy dispersive X-ray (EDX) spectroscopy. Catalytic properties of POM@TiO2 were also investigated by treating organic pollutants (typically, removal of 40 mL 20 mg L− 1 methylene blue (MB) by 10 mg POM@TiO2 was up to 99.5% within 3 min under ambient conditions and the photodegradation efficiency was obviously higher than bare TiO2 nanoparticles under irradiation).Novel composite materials based on D–π–A type polyoxometalates and TiO2 with excellent catalytic ability in treating organic pollutants
Co-reporter:Hui Duan, Zhi-Ming Zhang, Xin-Bao Han, Yi-Zhen Chen, Jian-Qiang Shen, Wei-Peng Wang, Xiao-Tao Zheng, Huan-Yu Zhou, En-Bo Wang
Inorganic Chemistry Communications 2013 Volume 33() pp:90-94
Publication Date(Web):July 2013
DOI:10.1016/j.inoche.2013.04.009
•3d–5p cluster-containing POM•Sandwich POM-based 2D supramolecular framework•Sandwich POM-based 2D frameworkA new sandwich-type tungstoantimonate (NH4)9{Cu3Sb(H2O)3(SbW9O33)2}·22H2O (1) was synthesized by reaction of the preformed large cluster [NaSb9W21O86]18 − ({Sb9W21}) and transition-metal cations. Compound 1 is a 3d–5p heterometallic cluster-containing sandwich-type tungstoantimonate, which was further connected by the H-bonding interactions into a (4, 4)-connected two dimensional (2D) supramolecular framework. Further, the introduction of the alkali metal cations into the reaction system leads to a 2D framework based on the sandwich-type tungstoantimonate by water substitution: Na(NH4)9{SbCu3Cl(SbW9O33)2}·14H2O (2).A new 3d–5p heterometallic cluster-containing sandwich-type tungstoantimonate was synthesized by reaction of the preformed large cluster [NaSb9W21O86]18 − and transition-metal cations.
Co-reporter:Ai-Xue Yan, Hua-Qiao Tan, Ding Liu, Zhi-Ming Zhang, En-Bo Wang
Inorganic Chemistry Communications 2013 Volume 29() pp:49-52
Publication Date(Web):March 2013
DOI:10.1016/j.inoche.2012.12.016
Two organic–inorganic hybrid compounds with the formula {[MnIII(Salen)(H2O)]4MoO4}·Cl2·16H2O (1) and {[MnIII(Salen)(H2O)]4WO4}·(CH3COO)2·11H2O (2) (Salen = Di-[2-hydroxyl-3-methoxyl-benzaldehyde] ethylenediamine) have been synthesized and structurally characterized by IR, UV–vis spectroscopy, TG analysis and single crystal X-ray diffraction. Structural analysis revealed that compounds 1 and 2 consist of a [MoO4]2 − or [WO4]2 − building unit and four {[MnIII(Salen)(H2O)]+ metal–organic moieties, respectively. In the crystal structure, the [MoO4]2 − or [WO4]2 − tetrahedra coordinated with four MnIII ions, resulting in the penta-nuclear heterometallic tetrahedra cluster compounds, which were rarely observed in the Mn-Salen system. Magnetic study revealed that there was antiferromagnetic coupling in the two compounds.A penta-nuclear {MMn4} (M = W and Mo) heterometallic clusters with four Mn-Salens exhibit the tetrahedron structural and a 3D supramolecular porous framework.Highlights► Two penta-nuclear {MMn4} heterometallic clusters are both tetrahedral structure. ► Compounds 1 and 2 are both based on four Mn-Salens. ► Compounds 1 and 2 both exhibit a 3D supramolecular porous framework.
Co-reporter:Jian-Sheng Li, Xiao-Jing Sang, Wei-Lin Chen, Lan-Cui Zhang, Zhong-Min Su, Chao Qin, En-Bo Wang
Inorganic Chemistry Communications 2013 Volume 38() pp:78-82
Publication Date(Web):December 2013
DOI:10.1016/j.inoche.2013.10.027
•The polyoxometalates (POMs) sensitized solar cell (PSSC) was studied firstly.•It is breakthrough to put forward that POMs export electrons under irradiation.•The energy level and band gap were investigated for the POMs base sensitizer.Keggin-type polyoxometalates (POMs) based photosensitizer [(CH3)4N]5[PW11O39RhCH2COOH]∙6H2O (PW11Rh-COOH) was firstly explored for assembling the POMs sensitized solar cells (PSSC). Electrochemical measurement, UV–vis diffuse reflectance spectrum, Surface photovoltage spectrum, and X-ray photoelectron spectroscopy demonstrated that PW11Rh-COOH displayed higher photovoltaic response than that of other POMs because of the better visible-light response, energy level matching and higher carrier separation efficiency.Keggin-type polyoxometalates (POMs) based photosensitizer [(CH3)4N]5[PW11O39RhCH2COOH]∙6H2O (PW11Rh-COOH) was firstly explored for assembling the POMs sensitized solar cells (PSSC), which displayed higher photovoltaic response than that of other POMs because of the better visible-light response, energy level matching and higher carrier separation efficiency.
Co-reporter:Qing Lan, Huaqiao Tan, Ding Liu, Enbo Wang
Journal of Solid State Chemistry 2013 Volume 199() pp:129-133
Publication Date(Web):March 2013
DOI:10.1016/j.jssc.2012.12.005
In this paper, three new extended solid frameworks based on polyoxoanion [MnV13O38]7−: K0.5Na2.5Co2[MnV13O38]·22H2O (1), K1.5Na1.5Mn2[MnV13O38] 22H2O (2) and K0.5Na2.5Ni2[MnV13O38] 22H2O (3) have been synthesized and characterized by elemental analysis, IR spectrum, UV–Vis spectrum, thermal gravimetric analysis, magnetism, electrochemical analyses and single crystal X-ray diffraction. The structure analyses reveal that the polyoxoanions in compounds 1–3 are isostructural, which can be described as two transition metal-supported {M2(H2O)10(MnV13O38)} (M=Co2+, Mn2+ and Ni2+) units connected by a K+. And then the polyoxoanions are stacked by the electrostatic interactions with other K+ and Na+ cation to form a 2D layer. The variable-temperature magnetic susceptibility of compound 1 has been studied as the example, which shows an antiferromagnetic interaction.Graphical abstractHighlights► The polyoxoanions [MnV13O38]7− has been investigated scarcely. ► A series of [MnV13O38]7−-based extended frameworks have been reported. ► The compounds are the first TM supported [MnV13O38]7−-based materials.
Co-reporter:Jiang-Hong He, Dong-Rong Xiao, Hai-Yan Chen, Dian-Zhen Sun, Shi-Wei Yan, Xin Wang, Zhong-Li Ye, Qun-Li Luo, En-Bo Wang
Journal of Solid State Chemistry 2013 Volume 198() pp:279-288
Publication Date(Web):February 2013
DOI:10.1016/j.jssc.2012.10.015
Six novel 2D metal–quinolone complexes, namely [Cd(cfH)(bpdc)]H2O (1), [M(norfH)(bpdc)]H2O (M=Cd (2) and Mn (3)), [Mn2(cfH)(odpa)(H2O)3]0.5H2O (4), [Co2(norfH)(bpta)(μ2-H2O)(H2O)2]H2O (5) and [Co3(saraH)2(Hbpta)2(H2O)4]9H2O (6) (cfH=ciprofloxacin, norfH=norfloxacin, saraH=sarafloxacin, bpdc=4,4′-biphenyldicarboxylate, odpa=4,4′-oxydiphthalate, bpta=3,3′,4,4′-biphenyltetracarboxylate) have been synthesized and characterized. Compounds 1–3 consist of 2D arm-shaped layers based on the 1D {M(COO)}nn+ chains. Compounds 4 and 5 display 2D structures based on tetranuclear manganese or cobalt clusters with (3,6)-connected kgd topology. Compound 6 exhibits a 2D bilayer structure, which represents the first example of metal–quinolone complexes with 2D bilayer structure. By inspection of the structures of 1–6, it is believed that the long aromatic polycarboxylate ligands are important for the formation of 2D metal–quinolone complexes. The magnetic properties of compounds 3–6 was studied, indicating the existence of antiferromagnetic interactions. Furthermore, the luminescent properties of compounds 1–2 are discussed.Graphical abstractSix novel 2D metal–quinolone complexes have been prepared by self-assemblies of the quinolones and metal salts in the presence of long aromatic polycarboxylates .Highlights►Compounds 1–3 consist of novel 2D arm-shaped layers based on the 1D {M(COO)}nn+ chains. ► Compounds 4 and 5 are two novel 2D layers based on tetranuclear Mn or Co clusters with kgd topology. ► Compound 6 is the first example of metal–quinolone complexes with 2D bilayer structure. ► Compounds 1–6 represent six unusual examples of 2D metal–quinolone complexes.
Co-reporter:Xiu-ping Zheng, Ying Lu, Huan Zhang, Zhi-ming Zhang, En-bo Wang
Inorganic Chemistry Communications 2013 Volume 33() pp:29-32
Publication Date(Web):July 2013
DOI:10.1016/j.inoche.2013.04.008
•Two new MOFs based on Cu12 units were synthesized and characterized.•1 and 2 represent the rare examples of MOFs constructed by cyclic type SBUs.•1 and 2 exhibit photocatalytic activity for the degradation of RhB.Two new metal–organic frameworks based on cyclic-type dodecanuclear copper units, (Me4N)6[Cu12(OMe)6(pz)6(BTC)6]·18H2O 1 and (Me4N)6[Cu12(OH)6(pz)6(BTC)6]·21H2O 2 (pz = pyrazolate, BTC = 1,3,5-benzenetricarboxylate), have been prepared by the solvothermal reactions of copper salts, Hpz and H3BTC ligands. The cyclic-type Cu12 unit in 1 and 2 is constructed by twelve CuII ions linked together by μ2-OH or μ2-OMe and unidentate carboxylate groups at the inner- and μ-pz and bidentate carboxylate groups at the outer surface of the toroid. In 1 and 2, each Cu12 unit is connected to 12 other units by BTC linkers, leading to 12-connected three-dimensional porous frameworks. The photocatalytic investigations indicate that compounds 1 and 2 exhibit photocatalytic activity for the degradation of RhB.Two new 12-connected MOFs based on dodecanuclear copper units were synthesized and characterized.
Co-reporter:Hua Lin, Yu-Wei Zhang, Yong-Li Bao, Yin Wu, Lu-Guo Sun, Chun-Lei Yu, Yan-Xin Huang, En-Bo Wang, Yu-Xin Li
Biochemical Systematics and Ecology 2013 Volume 51() pp:184-188
Publication Date(Web):December 2013
DOI:10.1016/j.bse.2013.08.010
•A pair of new isomers and ten known compounds were isolated from Juglans mandshurica.•The two new isomers belong to dibenz[cd,lm]perylene derivatives.•Structures were elucidated on the basis of spectroscopic analysis.•Chemotaxonomic importance of the isolates was discussed.A pair of new dibenz[cd,lm]perylene derivatives, juglanperylenone A (1a) and juglanperylenone B (1b), along with ten known compounds, including four anthraquinones (2–5), two coumarins (6–7) and four triterpenoids (8–11), were isolated from the stem bark of Juglans mandshurica Maxim. Their structures were elucidated on the basis of spectroscopic evidence, including 1D and 2D NMR, HR-TOF-MS, and by comparison with literature data. In addition, the chemotaxonomic significance of the isolates was also discussed in this paper.Chemical structures of juglanperylenone A and juglanperylenone B.
Co-reporter:Peng Huang ; Chao Qin ; Zhong-Min Su ; Yan Xing ; Xin-Long Wang ; Kui-Zhan Shao ; Ya-Qian Lan
Journal of the American Chemical Society 2012 Volume 134(Issue 34) pp:14004-14010
Publication Date(Web):August 20, 2012
DOI:10.1021/ja303723u
Three novel polyoxoniobates, KNa2[Nb24O72H21]·38H2O (1), K2Na2[Nb32O96H28]·80H2O (2), and K12[Nb24O72H21]4·107H2O (3) with molecular triangle, molecular square, and cuboctahedral molecular cage geometries, respectively, have been successfully synthesized by conventional aqueous methods. All the compounds are built from [Nb7O22]9– fundamental building units. Compound 1 is the first isolated {Nb24O72} cluster, featuring three heptaniobate clusters linked in a ring by three additional NbO6 octahedra, while compound 2 is the largest isopolyoxoniobate cluster reported to date, consisting of four heptaniobate clusters linked by four additional NbO6 octahedra. Compound 3 is the largest solid aggregation of polyoxoniobates, assembled by four {KNb24O72} clusters joined by four K ions. To our knowledge, it is the first time these polyoxoniobate clusters have been crystallized with only alkali-metal counterions, thereby giving them the possibility of being redissolved in water. ESI-MS spectra indicate that compounds 1 and 2 remain structural integrity when the pure, crystalline polyanion salts are dissolved in water, while compound 3 is partially assembled into Nb24 fragments. The UV–vis diffuse reflectance spectra of these powder samples indicate that the corresponding well-defined optical absorption associated with Eg can be assessed at 3.35, 3.17, and 3.34 eV, respectively, revealing the presence of an optical band gap and the nature of semiconductivity with a wide band gap. UV-light photocatalytic H2 evolution activities were observed for these compounds with CoIII(dmgH)2pyCl as a cocatalyst and TEA as a sacrificial electron donor.
Co-reporter:Huan Zhang, Ying Lu, Zhiming Zhang, Hai Fu, Yangguang Li, Dirk Volkmer, Dmytro Denysenko and Enbo Wang
Chemical Communications 2012 vol. 48(Issue 58) pp:7295-7297
Publication Date(Web):07 Jun 2012
DOI:10.1039/C2CC32120C
A 12-connected metal–organic framework based on an unprecedented cyclic Cu12 cluster with a large internal cavity has been prepared, and its cation exchange property was determined.
Co-reporter:Huaqiao Tan, Yangguang Li, Weilin Chen, Aixue Yan, Ding Liu, and Enbo Wang
Crystal Growth & Design 2012 Volume 12(Issue 3) pp:1111-1117
Publication Date(Web):January 30, 2012
DOI:10.1021/cg2004936
Five new compounds based on the Waugh-type polyoxoanion [MnMo9O32]6– Na4Mn[MnMo9O32]·11.5H2O (1), KNa3Mn[MnMo9O32]·9H2O (2), Na2Ni2[MnMo9O32]·12H2O (3), l-Mn3[MnMo9O32]·13H2O (4a), d-Mn3[MnMo9O32]·13H2O (4b), and l-Ni3[MnMo9O32]·11.5H2O (5a) have been synthesized. In these compounds, with the changes of Na+/TM (TM = Mn2+, Ni2+) in the crystal, the homochiral interactions were extended from two adjacent [MnMo9O32]6– to one-dimensional (compounds 1 and 2), two-dimensional (compound 3), and three-dimensional (compounds 4 and 5) systems, respectively.
Co-reporter:Jianghong He, Guangju Zhang, Dongrong Xiao, Haiyan Chen, Shiwei Yan, Xin Wang, Juan Yang and Enbo Wang
CrystEngComm 2012 vol. 14(Issue 10) pp:3609-3614
Publication Date(Web):28 Feb 2012
DOI:10.1039/C2CE25038A
Two novel three-dimensional (3D) chiral coordination polymers, namely [Zn4(btc)2(Hbtc)(L-His)2(H2O)4]·1.5H2O (L-1) and [Zn4(btc)2(Hbtc)(D-His)2(H2O)4]·1.5H2O (D-1), have been assembled from zinc salt with mixed ligands 1,3,5-benzenetricarboxylic acid (H3btc) and chiral histidine (His). Their structures were determined by single-crystal X-ray diffraction analyses, elemental analyses, infrared (IR) spectra, X-ray powder diffraction, circular dichroism (CD) spectra, and thermogravimetric (TG) analysis. Compounds L-1 and D-1 are enantiomers and exhibit unique 3D chiral frameworks containing fivefold interwoven helices, which represent the first examples of chiral metal–amino acid complexes containing n-fold interwoven helices. Furthermore, the helices in L-1 are left-handed, while those in D-1 are right-handed, which indicate that the handedness of helices can be controlled by the chirality of His bound to the metal. More wonderfully, the 3D framework can be simplified to a (3,4)-connected chiral net with an unprecedented (4·92)(4·94·11) topology. Moreover, the luminescent properties of compound L-1 are discussed.
Co-reporter:Shuang-Shuang Guo, Chao Qin, Yang-Guang Li, Ying Lu, Zhong-Min Su, Wei-Lin Chen and En-Bo Wang
Dalton Transactions 2012 vol. 41(Issue 8) pp:2227-2230
Publication Date(Web):03 Jan 2012
DOI:10.1039/C2DT11897A
A long-term stable Pt counter electrode modified by POM-based multilayer film has been fabricated by the electrochemical deposition method, which can markedly increase short-circuit photocurrent, open-circuit voltage and the conversion efficiency when used in dye-sensitized solar cells (DSSCs).
Co-reporter:Zhu-Jun Liu, Zhi-Ming Zhang, Hai Fu, Yang-Guang Li, Wei-Lin Chen, Hai-Hong Wu and En-Bo Wang
Dalton Transactions 2012 vol. 41(Issue 38) pp:11700-11705
Publication Date(Web):01 Aug 2012
DOI:10.1039/C2DT30742A
Two new {P8W48} wheel-based compounds, Na12Li16{[Cu(H2O)]2[Cu4(OH)4(H2O)8]2P8W48O184}·55H2O (1), and K4Na24Li10{(MoO2)2(P8W48O184)}·61H2O (2) have been synthesized by a conventional aqueous solution method, and characterized by UV, IR, TG analysis, XPRD, 31P NMR, XPS, single-crystal X-ray diffraction analyses, magnetic study and electrochemistry study. In compound 1, a wheel-type {P8W48} containing two {Cu4} clusters and two isolated Cu cations results in a 10-Cu-containing polyoxotungstate, which represents the first {P8W48}-based compound trapping two transition metal (TM) clusters in its inner cavity. Further, the polyoxoanion was connected by Na+ and Li+ cations into a 3D framework. Compound 2 is a 2-Mo-containing {P8W48}-based polyoxotungstate. Magnetic study indicates that antiferromagnetic interactions exist in compound 1.
Co-reporter:Zhen-Li Wang, Hua-Qiao Tan, Wei-Lin Chen, Yang-Guang Li and En-Bo Wang
Dalton Transactions 2012 vol. 41(Issue 33) pp:9882-9884
Publication Date(Web):22 Jun 2012
DOI:10.1039/C2DT30663H
A new dimer polyoxoniobate [Cu(en)2]11K4Na2[KNb24O72H9]2·120H2O (1) has been synthesized and systematically characterized. Visible light photocatalytic H2 evolution activity was researched with 1 as the visible-light photosensitizer and catalyst, cobaloximes [CoIII(dmgH)2pyCl] as the co-catalysts, and triethylamine (TEA) as the sacrificial electron donor.
Co-reporter:Dongrong Xiao, Haiyan Chen, Dianzhen Sun, Jianghong He, Shiwei Yan, Juan Yang, Xin Wang, Ruo Yuan and Enbo Wang
CrystEngComm 2012 vol. 14(Issue 8) pp:2849-2858
Publication Date(Web):10 Feb 2012
DOI:10.1039/C2CE06428F
A series of barium-4,4′-sulfonyldibenzoate (sdba) coordination polymers, namely, [Ba(μ2-OH2)(sdba)(H2O)3]·0.5H2O (1), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5ben·H2O (2), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5tolu·H2O (3), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5bpy·H2O (4), [Ba(μ2-OH2)(sdba)(H2O)3]·0.25bim·H2O (5), [Ba(μ2-OH2)(sdba)(H2O)3]·0.5dfb·0.25H2O (6) and [Ba(μ2-OH2)(sdba)(H2O)3]·3.5H2O (7) (ben = benzene, tolu = toluene, bpy = 2,2′-bipyridine, bim = 1,4-bis(imidazol-1-yl)butane, dfb = 1,3-difluoro-benzene (a fragment of fluconazole)), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectra, and TG analyses. Compounds 1–7 are built upon similar sidearm-containing 2D bilayer motifs, and the adjacent layers are stacked in a mutual interdigitation, such that channels are created. The channels form a hydrogen-bonded interior for guest molecules. In practice, compounds 1 and 7 contain different quantities of free water molecules as guests in the channels, whereas compounds 2–6 contain ben, tolu, bpy, bim and dfb molecules as well as free water molecules in their channels, respectively. The different interlayer distances and free void spaces of 1–7 indicate the effect of guest-induced expanding and shrinking porous modulation, and give a clue to the dynamic arrangement in this system. This indicates the obtained compounds (1–7) are categorized as a member of a new generation of compounds tending towards functional porous coordination polymers. In addition, the photoluminescent properties for all the compounds (1–7) were investigated in detail.
Co-reporter:Tian-zhan Zhang, Ying Lu, Yang-guang Li, Zhiming Zhang, Wei-lin Chen, Hai Fu, En-bo Wang
Inorganica Chimica Acta 2012 Volume 384() pp:219-224
Publication Date(Web):1 April 2012
DOI:10.1016/j.ica.2011.12.006
Three new Fe-containing MOFs, H3O[Fe5(BTC)3(OAc)2(DMF)2]·H2O 1, [FeNa(m-BDC)2]·NH2(CH3)22 and [N(CH3)4]2[Fe3(HBTC)(BTC)2(H2O)]·5.5H2O 3 (BTC = 1,3,5-benzenetricarboxylate, m-BDC = 1,3-benzene-dicarboxylate), have been synthesized from the solvothermal reactions of iron salts and carboxylate ligands. The framework of 1 is constructed from two kinds of secondary building units (SBUs): the sinusoidal chain of iron octahedra SBU [Fe2(COO)6]n2n− and paddle-wheel SBU [Fe2(COO)4(DMF)]. Compound 1 represents the first example of Fe-containing MOFs constructed from two kinds of SBUs. The framework of 2 is built from zigzag-chain SBUs [FeNa(COO)6]n3n− and m-BDC linkers. The framework of 3 is formed by linear tri-nuclear iron SBUs [Fe3(COO)8(H2O)]2− and triangular BTC linkers. To our knowledge, the Fe-containing sinusoidal chain SBU in 1, zigzag-chain SBU in 2 and linear tri-nuclear iron SBU in 3 are found in Fe-containing MOFs for the first time. Magnetic investigation indicates the present of antiferromagnetic exchange interaction within the iron units of compounds.Graphical abstractThree new metal–organic frameworks with FeII-containing SBUs, namely, H3O[Fe5(BTC)3(OAc)2(DMF)2]·H2O (1), [FeNa(m-bdc)2]·NH2(CH3)2 (2) and [N(CH3)4]2[Fe3(Hbtc)(btc)2(H2O)]·5.5H2O (3) have been solvothermal synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TG), UV analysis and single-crystal X-ray diffraction. The magnetic properties of these three compounds have also been investigated.Highlights► MOFs with two kinds of SBUs were synthesized. ► Hybrid compounds built up from inorganic chain-like SBUs instead of clusters. ► Iron complexes display a range of antiferromagnetic exchange interaction.
Co-reporter:Hai-Yan Chen, Dong-Rong Xiao, Shi-Wei Yan, Jiang-Hong He, Juan Yang, Xin Wang, Ruo Yuan, En-Bo Wang
Inorganica Chimica Acta 2012 Volume 387() pp:283-288
Publication Date(Web):30 May 2012
DOI:10.1016/j.ica.2012.01.035
The first two three-dimensional (3D) pillared metal–olsalazine complexes, namely [Co(osa)0.5(bim)0.5(H2O)] (1) and [Cd(osa)0.5(bim)0.5(H2O)] (2) (H4osa = 3,3-azo-bis(6-hydroxybenzoic acid), bim = 1,4-bis(imidazol-1-yl)butane) have been hydrothermally synthesized and further characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectra and TG analyses. Compounds 1 and 2 are isostructural, and their frameworks are composed of infinite rod-shaped secondary building units (SBUs) that are bridged by osa ligands to form 2D layers, which are further pillared by bim ligands in the third dimension. To the best of our knowledge, it is the first time that 3D pillared-layer frameworks involving infinite rod-shaped SBUs have been obtained in the realm of metal–olsalazine complexes. The magnetic property of 1 and photoluminescence of 2 have also been investigated.Graphical abstractThe first two 3D pillared metal–olsalazine complexes, based on infinite rod-shaped secondary building units, are reported, which also represent the first 3D coordination polymers constructed from the mixed olsalazine and N-containing ligands and exhibit good magnetic or luminescent properties.Highlights► Compounds 1 and 2 are the first 3D pillared metal–olsalazine complexes. ► Compounds 1 and 2 represent the first metal–olsalazine complexes containing rod-shaped SBUs. ► The magnetic data of 1 indicate the existence of antiferromagnetic interactions. ► Compound 2 displays good luminescent property.
Co-reporter:Qiong Wu, Shi-Wei Lin, Yang-Guang Li, En-Bo Wang
Inorganica Chimica Acta 2012 Volume 382() pp:139-145
Publication Date(Web):15 March 2012
DOI:10.1016/j.ica.2011.10.028
By combination of metal–Schiff-base complexes and A-type Anderson heteropolymolybdates, two new metal–Schiff-base polyoxometalate hybrid compounds [Mn(salen)(H2O)2]2Na3[IMo6O24]·18H2O (1) and [Mn(salpn)(H2O)2]2Na3[IMo6O24]·10H2O (2) (salen = N,N′-ethylene-bis(salicylideneiminate) and salpn = N,N′-(1,3-propylene)bis(salicylideneiminate)) have been successfully isolated. Compounds 1 and 2 were characterized by the single crystal X-ray diffraction analysis, elemental analysis, IR spectroscopy, TG analyses and XPS spectra. Single-crystal X-ray diffraction analysis revealed that both compounds exhibit 3-D supramolecular networks stabilized by electrostatic attraction and/or extensive hydrogen-bonding interactions. Moreover, compounds 1 and 2 represent first two examples of organic–inorganic composite supramolecular compounds based on A-type Anderson polyanion and metal–Schiff-based complexes. Photocatalytic experiment indicates that both compounds exhibit good catalytic activities for photodegradation of RhB with UV irradiation.Graphical abstractThe first two schiff-base containing A-type polyoxometalates supermolecule [Mn(salen)(H2O)2]2Na3[IMo6O24]·18H2O and [Mn(salpn)(H2O)2]2Na3[IMo6O24]·10H2O has been synthesized and characterized, photocatalysis properties of these two compounds have also been investigated.Highlights► Two new metallosalen-POM complexes have been isolated. ► Interesting supramoleculars are assembled by H-bond and π-π interactions. ► Both compounds photocatalytic activity in the reduction of some organic dyes.
Co-reporter:Lin Liu, Shiming Wang, Weilin Chen, Enbo Wang
Materials Letters 2012 Volume 78() pp:22-24
Publication Date(Web):1 July 2012
DOI:10.1016/j.matlet.2012.02.132
A simple approach was presented to fabricate Keggin-type polyoxometalates (POMs) hollow spheres (KPHS) using the colloidal carbon spheres as the hard templates. The C@POMs core-shell colloids were successfully prepared by using the highly uniform carbon microspheres as the hard templates without any surface modifications. And then a calcination treatment of the POMs modified carbon spheres (C@POMs) was employed to remove the carbon cores, resulting in the final products of KPHS. The as-prepared products possessed the intrinsic properties of POMs. In addition, the KPHS represents good electrochemical and electrocatalytic properties. This work may provide the new insights into preparing POMs-based nano/microstructures.A simple approach was presented to fabricate Keggin-type polyoxometalates (POMs) hollow spheres (KPHS) using the colloidal carbon spheres as the hard templates. The C@POMs core-shell colloids were successfully prepared by using the highly uniform carbon microspheres as the hard templates without any surface modifications. And then a calcination treatment of the POMs modified carbon spheres (C@POMs) was employed to remove the carbon cores, resulting in the final products of KPHS. This work may provide the new insights into preparing POMs-based nano/microstructures.Highlights► The Keggin-type polyoxometalates (POMs) hollow spheres were successfully synthesized. ► The hollow spheres represent good electrochemical and electrocatalytic properties. ► This strategy opens an avenue for the preparation of POM-based nano/microstructures.
Co-reporter:Zan-Jiao Wang, Lan-Cui Zhang, Zai-Ming Zhu, Wei-Lin Chen, Wan-Sheng You, En-Bo Wang
Inorganic Chemistry Communications 2012 Volume 17() pp:151-154
Publication Date(Web):March 2012
DOI:10.1016/j.inoche.2011.12.038
Two new sandwich-type tungstobismuthates containing carboxyethyltin groups and transition metals, Na8K2[{Co(H2O)3}2{Sn(CH2)2COO}2·(B-β-BiW9O33)2]·25H2O (1) and K10[{Mn(H2O)3}2{Sn(CH2)2COO}2·(B-β-BiW9O33)2]·30H2O (2) have been synthesized in the aqueous solutions and characterized by IR, TG, NMR and XRD. Single crystal X-ray diffraction analysis reveals that two 3d-transition metal (TM) cations and two organometallic (OM) groups in the central belt of the two complexes are all sandwiched by two B-β-[BiW9O33]9− units. The two compounds represent the first transition metal and carboxyethyltin-decorated polyoxometalate complexes. Structural analyses reveal that the reaction processes involving the α → β isomerization of [BiW9O33]9− unit and the hydrolysis of ester group. Both compounds have high thermal stabilities.Two new sandwich-type tungstobismuthates containing carboxyethyltin groups and transition metals are obtained, displaying high thermal stabilities.Highlights► The organotin groups are firstly decorated on the B-β-[BiW9O33]9− units. ► The two compounds represent the first transition metal and carboxyethyltin-decorated polyoxometalate complexes. ► Compounds 1 and 2 have high thermal stabilities.
Co-reporter:Qiong Wu, Xiuli Hao, Xiaojia Feng, Yonghui Wang, Yangguang Li, Enbo Wang, Xiangqing Zhu, Xinghua Pan
Inorganic Chemistry Communications 2012 Volume 22() pp:137-140
Publication Date(Web):August 2012
DOI:10.1016/j.inoche.2012.05.044
A new organic–inorganic hybrid compound (NH4)2[{Mn(salen)(H2O)}6V6O18](NO3)2·30H2O (salen2− = N,N′-(ethylene)bis(salicylideneiminate)) (1) was synthesized by the reaction between NH4VO3 and [Mn(salen)(H2O)2]ClO4 in a methanol–water solution with pH = 5.0 adjusted by nitric acid. Compound 1 was characterized by elemental analyses, TG, IR, UV–vis, XPS and the single-crystal X-ray diffraction. Compound 1 possesses a discrete cyclic hexanuclear vanadates, which is unprecedentedly grafted by six [Mn(salen)(H2O)2] units. Such a new hybrid compound displays good UV photocatalytic activity for RhB degradation.A new cyclic polyoxovanadate decorated by six {MnIII–Schiff-base} units was synthesized, exhibiting good UV photocatalytic activity for RhB degradation.Highlights► A new hybrid compound 1 based on polyoxovanadate and MnIII–Schiff-base units is synthesized. ► The discrete hexanuclear vanadate is unprecedentedly decorated by six MnIII–Schiff-base units. ► Compound 1 shows good UV photocatalytic activity for RhB degradation.
Co-reporter:Hai Hong Wu, Zhi Ming Zhang, En Bo Wang
Chinese Chemical Letters 2012 Volume 23(Issue 3) pp:355-358
Publication Date(Web):March 2012
DOI:10.1016/j.cclet.2012.01.013
A pure inorganic porous framework based on the tungstoferrate [FeW12O40]5−, Fe(H2O)6H[Na6FeW12O40]2·44H2O (1) was obtained by the conventional aqueous solution method and characterized by elemental analysis, TG, FT-IR, UV–vis spectroscopy. Single-crystal X-ray diffraction analyses reveal that compound 1 crystallizes in the space group Fm-3m, which is composed of a porous inorganic framework [Na6FeW12O40]n with two kinds of pores A and B, accommodating Fe(H2O)6 units in pore A, which was observed rarely in the pure inorganic framework.
Co-reporter:Huan Zhang, Ying Lu, Zhi-ming Zhang, En-bo Wang
Inorganic Chemistry Communications 2012 Volume 17() pp:9-12
Publication Date(Web):March 2012
DOI:10.1016/j.inoche.2011.11.040
A new metal–organic framework based on hexanuclear copper units, Cu6(μ3-O)(μ3-OH)(pz)6(btc) (pz = pyrazolate, btc = 1,3,5-benzenetricarboxylate) 1, has been prepared by the hydrothermal reaction of Cu2 + ions, Hpz and H3btc ligands in a methanolic solution. The hexanuclear copper building unit in 1 is composed of two triangular Cu3O(H)(pz)3 units bridged by carboxyl groups, in which each Cu center is coordinatively unsaturated with open coordination sites. The photocatalytic investigation indicates that compound 1 exhibits a higher photocatalytic activity for the degradation of Rhodamine B.A new MOF based on hexanuclear copper units was synthesized and structurally characterized as a (3,3)-connected network.Highlights► A new MOF based on hexanuclear copper units was synthesized and characterized. ► The first example of MOFs based on Cu6 unit constructed by two Cu3(μ3-O) units. ► Each copper center is coordinatively unsaturated with open coordination sites. ► Compound 1 exhibits higher photocatalytic activity for the degradation of RhB.
Co-reporter:Lin Liu, Shi-Ming Wang, Wei-Lin Chen, Ying Lu, Yang-Guang Li, En-Bo Wang
Inorganic Chemistry Communications 2012 Volume 23() pp:14-16
Publication Date(Web):September 2012
DOI:10.1016/j.inoche.2012.05.025
A high nuclear lanthanide-containing polyoxometalate aggregate {[(CH3)3N(CH2)2OH]2(NH4)12}[Ce4(Mo4)(H2O)16(Mo7O24)4]·8H2O has been successfully synthesized in choline chloride/urea eutectic mixture. This method in synthesizing this anti-HIV activity aggregate has the advantages of convenience, facility, saving time and absence of additional noxious organic reagents. It has been characterized by XPS, IR, UV–vis spectra, TG analyses, power X-ray diffraction and single crystal X-ray diffraction. The CV property of the compound has also been tested.A cerium-containing polyoxometalate aggregate has been successfully synthesized in choline chloride/urea eutectic mixture. This route has the advantages of convenience, facility, saving time and absence of additional noxious organic reagents.Highlights► A cerium-containing anti-HIV activity polyoxometalate aggregate was synthesized in a eutectic mixture. ► It is a new synthesis route for polyoxometalate based aggregates. ► This method has the advantages of convenience, facility, saving time and without additional noxious organic reagent.
Co-reporter:Xin-Bao Han, Zhi-Ming Zhang, Zhi-Shu Wang, Huan Zhang, Hui Duan, En-Bo Wang
Inorganic Chemistry Communications 2012 Volume 18() pp:47-49
Publication Date(Web):April 2012
DOI:10.1016/j.inoche.2012.01.006
A purely inorganic porous framework based on Keggin polyoxoanions K2NaH2[BW12O40]·12H2O (1) has been prepared and characterized by single-crystal X-ray analysis, IR and XRD analysis. Compound 1 crystallized in a chiral space group P6(4)22 with hexagonal symmetry. In compound 1, the 3D inorganic porous framework possesses of the 1D hexagon channels along the c axis. Furthermore, the porous framework exhibits reversible water sorption capability.A new purely inorganic chiral 3D porous framework based on Keggin polyoxoanions K2NaH2[BW12O40]•12H2O (1) has been synthesized with the 1D hexagon channels along the c axis.Highlights► A purely inorganic porous framework was synthesized and characterized. ► Compound 1 represents a chiral example of MOFs based on POM building. ► The porous framework of 1 exhibits reversible water sorption capability.
Co-reporter:Xiaojing Sang, Jiansheng Li, Weilin Chen, Enbo Wang
Materials Letters 2012 Volume 87() pp:39-42
Publication Date(Web):15 November 2012
DOI:10.1016/j.matlet.2012.07.100
With the assistance of polyoxometalates (POM), ZnO polyhedra with the mean length of 200 nm and mean diameter of 100 nm are synthesized by a simple solvothermal route in an alkali solution. Parallel experiments without POM were carried out to investigate the formation process of ZnO polyhedra and the results showed that POM played a key role in the formation of ZnO polyhedra. A possible formation mechanism was also proposed. Meanwhile, the as-prepared ZnO powder was used to assemble dye-sensitized solar cells (DSSC) photoanodes, the overall solar-to-electric energy conversion efficiency was up to 2.45%, which were obtained using TiCl4 post-treatment.Graphical abstractZnO polyhedrons were synthesized by a simple solvothermal route with the assistance of K7HNb6O19. ZnO nanoclusters generated at the beginning of the reaction. POMs adsorb on the surface of the nanoclusters, inhibiting their further growth into nanorods and facilitating them gather into the relatively stable polyhedral structure.Highlights► ZnO polyhedra were synthesized with the assistance of isopolyoxometalates. ► K7HNb6O19 was first introduced into the preparation of ZnO. ► A possible formation mechanism was proposed. ► Polyoxometalate-assisted synthesized ZnO was first introduced into the field of DSSC. ► Conversion efficiency was significantly improved by TiCl4 post-treatment.
Co-reporter:Zhi-Shu Wang, Zhi-Ming Zhang, Xin-Bao Han, Huan Zhang, En-Bo Wang
Inorganic Chemistry Communications 2012 20() pp: 196-200
Publication Date(Web):
DOI:10.1016/j.inoche.2012.03.007
Co-reporter:Dr. Zhi-Ming Zhang;Dr. Shuang Yao;Dr. Yang-Guang Li;Xin-Bao Han; Zhong-Min Su;Zhi-Shu Wang; En-Bo Wang
Chemistry - A European Journal 2012 Volume 18( Issue 30) pp:9184-9188
Publication Date(Web):
DOI:10.1002/chem.201200555
Co-reporter:Dr. Hai Fu; Chao Qin; Ying Lu;Dr. Zhi-Ming Zhang; Yang-Guang Li; Zhong-Min Su;Dr. Wen-Liang Li ; En-Bo Wang
Angewandte Chemie International Edition 2012 Volume 51( Issue 32) pp:7985-7989
Publication Date(Web):
DOI:10.1002/anie.201202994
Co-reporter:Qing Lan;Ying Lu;Yang-Guang Li;Hua-Qiao Tan;Ding Liu
Transition Metal Chemistry 2012 Volume 37( Issue 5) pp:445-451
Publication Date(Web):2012 August
DOI:10.1007/s11243-012-9608-1
Two organic–inorganic hybrid complexes based on a Keggin-type polyoxoanion, namely [Ni2(H2O)2(bipy)4(Hbipy)][AlW12O40]·7H2O 1 and [Ni2Cl2(bipy)3(Hbipy)2][SiW12O40]·2.5H2O 2 (bipy = 4,4′-bipy), have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Complexes 1 and 2 possess similar 2D layer structures, constructed from 1D zigzag chains {Ni(bipy)}n2n+ and alternatively arranged Keggin anion and bipy linkers. Photocatalytic investigations indicate that both 1 and 2 exhibit photocatalytic activity for the degradation of Rhodamine B.
Co-reporter:ZhenLi Wang;Ying Lu;YangGuang Li;ShiMing Wang;EnBo Wang
Science Bulletin 2012 Volume 57( Issue 18) pp:2265-2268
Publication Date(Web):2012 June
DOI:10.1007/s11434-012-5050-1
The visible light photocatalytic H2 evolution activities of a series of transition-metal substituted Keggin-structure heteropoly blues K6SiW11O39M(H2O)·nH2O (M = Co, Ni, Cu and Zn) were systematically studied with Pt nanoparticles as co-catalyst. The H2 evolution rates were 150, 98, 65 and 48 μmol h−1g−1 for SiW11Cu, SiW11Ni, SiW11Co and SiW11Zn, respectively, meaning that the order of photocatalytic activity of these heteropoly blues from transition-metal substituted polyoxometalates was: SiW11Cu > SiW11Ni > SiW11Co > SiW11Zn. The catalysts could be efficiently reused for at least 5 cycles.
Co-reporter:Jing-Xin Meng, Yang-Guang Li, Hai Fu, Xiao-Lan Wang and En-Bo Wang
CrystEngComm 2011 vol. 13(Issue 2) pp:649-655
Publication Date(Web):27 Sep 2010
DOI:10.1039/C0CE00356E
Two novel metal–organic frameworks (MOFs) based on different tetradentate in situ ligands, CuI3(L1)2(L2)[PMoVI8VV4O40(VIVO)2]·2H2O (1) and [CuI2Cl2(L3)] (2) (L1 = 1,4-bis(imidazol-1-ylmethyl)benzene, L2 = 1,2,4,5-tetra(4-pyridyl)-benzene L3 = a-1-hydroxy-e,e,e,e-1,2,4,5-tetra(4-pyridyl)cyclohexane) have been rationally hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, TG analyses, and single-crystal X-ray diffraction, respectively. Here, compound 1 represents the first example that dehydrogenative coupling has been employed to yield a novel tetradentate coplanar dye molecule in POM-based MOFs. It also exhibits unique 3D MOFs with two topologies (4284)(4283101)(86)2 and (4383)(4284)(446289)(4106183) due to different definitions of nodes. Compound 2 shows a two-fold diagonal/diagonal inclined interpenetration based on CuI ions and in situ synthesized ligands L3. Interestingly, reaction conditions play important roles in the domination of in situ ligands (L2 and L3) from the same precursor bpp (bpp = 1,3-bis(4-pyridyl)propane). Additionally, electrochemical and photocatalysis properties of compound 1 have also been minutely investigated.
Co-reporter:Jing-Xin Meng, Ying Lu, Yang-Guang Li, Hai Fu and En-Bo Wang
CrystEngComm 2011 vol. 13(Issue 7) pp:2479-2486
Publication Date(Web):03 Feb 2011
DOI:10.1039/C0CE00639D
By adjusting the molar ratio of the reactants H3PO4 and Na2MoO4, four new metal–organic frameworks, namely, CoH(bix)4[PMoVI8VV4O40(VIVO)2] (1), (H2bix)2(NaHP2Mo5O23)·2H2O (2), H2(bix)4[Cd(H2O)4][Cd(HPO4)4(H2PO4)4(MoO2)12 (OH)6]·10H2O (3) and (H2en)3(Co3P4Mo4O28) (4) (bix = 1,4-bis(imidazol-1-ylmethyl)benzene, en = 1,2-ethylenediamine), have been hydrothermally prepared and characterized by elemental analyses, IR spectroscopy, TG analyses, and single-crystal X-ray diffraction. Compound 1 consists of straight chains based on pseudo-Keggin [PMoVI8VV4O40(VIVO)2]3−polyanions and [CoH(bix)4]3+ complex fragments, which are further connected into a three-dimensional (3D) open framework by hydrogen bonding interactions between polyanions and organic bix ligands . Compound 2 shows 3D supramolecular networks constructed from weak interactions between free biprotonated bix, water and oxygen atoms of polyanions [P2Mo5O23]6−. In compound 3, [Cd(HPO4)4(H2PO4)4(MoO2)12(OH)6]4−polyanions are linked by [Cd(H2O)4]2+ cations to build one-dimensional (1D) chains. Then weak interactions between free bix ligands, water and oxygen atoms of the polyanions extend these 1D chains to 3D supramolecular frameworks. Compound 4 exhibits open-framework structures. Interestingly, it also shows 1D left and right-handed helical chains and 2D (6,3)-layers. The molar ratio of the reactants H3PO4 and Na2MoO4 influence the transformation of the phosphomolybdate clusters in compounds 1–4. The electrochemistry and photocatalysis properties of these compounds have also been investigated in this paper.
Co-reporter:Yan Ding, Jing-Xin Meng, Wei-Lin Chen and En-Bo Wang
CrystEngComm 2011 vol. 13(Issue 7) pp:2687-2692
Publication Date(Web):15 Feb 2011
DOI:10.1039/C0CE00967A
Four new supramolecular compounds, namely, [HMnII(bix)4][PMoVI8VV4O40(VIVO)2]·2H2O (1), [Zn(bix)4][PMoVI9VV3O40(VIVO)2]·2H2O (2), [Cu(bix)4][PMoVI9VV3O40(VIVO)2]·4H2O (3) and [CuI(bix)]2[CuI(bix)](bix)[PMo12O40]·4H2O (4) (bix = 1,4-Bis(imidazol-1-ylmethyl)benzene), have been synthesized under hydrothermal conditions, which are constructed from Keggin/pseudo-Keggin polyoxometalate (POM) secondary building units (SBUs) and transition metal complexes. Compound 1 consists of an infinite 1D chain constructed from [HMnII(bix)4]3+ cations and the reduced bi-capped pseudo-Keggin polyoxoanions [PMoVI8VV4O40(VIVO)2]3−. With the aid of hydrogen bonds, these 1D chains extend to 3D supramolecular frameworks. Compounds 2 and 3 are isostructural and consist of the bi-supporting Keggin polyoxoanions [PMoVI9VV3O40(VIVO)2]2− and [M(bix)4]2+ (M = Zn, Cu) coordination polymer fragments, resulting in the 3D supramolecular frameworks via weak interactions. Compound 4 is composed of the 1D ladder-like chains [Cu(bix)]nn+ which are filled in the 3D supramolecular cavities and stabilize the whole framework structures viahydrogen bonds. Interestingly, 3D architectures have been obviously changed by altering the POM SBUs from pseudo-Keggin to classical Keggin. Here, all these compounds are characterized by elemental analyses, IR, TG analyses and single-crystal X-ray diffractions. In addition, the electrochemical properties and photocatalytic properties of compounds 1–4 have been investigated.
Co-reporter:Jianghong He, Haiyan Chen, Dongrong Xiao, Dianzhen Sun, Guangju Zhang, Shiwei Yan, Guanghua Xin, Ruo Yuan and Enbo Wang
CrystEngComm 2011 vol. 13(Issue 15) pp:4841-4845
Publication Date(Web):15 Jun 2011
DOI:10.1039/C1CE05349C
The first entangled metal-ppa complex, containing unique 5-fold interlocking tri-flexure helices and 15-fold interwoven helices, defines an unprecedented 3-fold interpenetrated double-edged pseudo-diamondoid (pseudo-dia) network, which, not only represents the first and only example of interpenetrating metal-quinolone complex, but also represents the highest degree of interpenetration presently known for double-edged nets.
Co-reporter:Haiyan Chen, Dongrong Xiao, Linlin Fan, Jianghong He, Shiwei Yan, Guangju Zhang, Dianzhen Sun, Zhongli Ye, Ruo Yuan and Enbo Wang
CrystEngComm 2011 vol. 13(Issue 23) pp:7098-7107
Publication Date(Web):30 Sep 2011
DOI:10.1039/C1CE05573A
Four new entangled metal–organic polymers, namely [Cd2(sdba)2(Htpim)2(H2O)2]·5H2O (1), [Zn(sdba)(Htpim)] (2), [Cd(sdba)(bim)] (3), [Cd(sdba)(bimp)] (4) (sdba = 4,4′-sulfonyldibenzoate, Htpim = 2,4,5-tri(4-pyridyl)-imidazole, bim = 1,4-bis(imidazol-1-yl)butane, bimp = 1,4-bis(imidazol-1-yl)propane), have been hydrothermally synthesized and further characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analysis, IR spectra and TG analyses. Compound 1 consists of two identical 3D self-threading frameworks with CdSO4 topology, which exhibits a twofold interpenetrating architecture and represents the first entangled coordination polymer containing both interpenetration and self-threading features. Compound 2 exhibits a novel (1D → 3D) interdigitated architecture that is obtained from the self-assembly of 1D tubelike structures, in which each 1D tube is interdigitated by dangling arms from four adjacent tubes belonging to four different spatial orientations. Compounds 3 and 4 are close to being isostructural, and both exhibit a novel (2D → 3D) interdigitated architecture, which is assembled from hydrogen-bonded bilayer motifs that are formed by two kinds of chiral layers (one left-handed and the other right-handed) showing a deep mutual interdigitation. In addition, photoluminescent properties for 1–3 are investigated in detail.
Co-reporter:Huaqiao Tan, Weilin Chen, Ding Liu, Xiaojia Feng, Yangguang Li, Aixue Yan and Enbo Wang
Dalton Transactions 2011 vol. 40(Issue 33) pp:8414-8418
Publication Date(Web):19 Jul 2011
DOI:10.1039/C0DT01729A
Two asymmetric polyoxomolybdates Na6{Mo2O5[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]2}·16H2O (1) and (NH4)7Na{MoO2[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]}4·H2O (2) have been synthesized by the reactions of alendronic acid with molybdate. Structure analysis revealed that the polyoxoanions 1 and 2 can be described as dimeric and tetrameric aggregates of the {MoO3[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]} units respectively. Their tetrabutylammonium salts show efficient selective oxidation of benzyl alcohol to benzaldehyde with 72.5% and 81.5% benzyl alcohol conversion, and 87.1% and 82.4% benzaldehyde selectivity, respectively.
Co-reporter:Zhi-Ming Zhang, Yang-Guang Li, Shuang Yao and En-Bo Wang
Dalton Transactions 2011 vol. 40(Issue 24) pp:6475-6479
Publication Date(Web):19 May 2011
DOI:10.1039/C1DT10133A
Two nanosized hexameric polyoxometalate-based solid state assemblies (H2en)6Na15K9[Dy6Fe6(H2O)12(SiW10O38)6]·34H2O (1) and K13Na17[H2en]3[Tb6Fe6(H2O)12(SiW10O38)6]·40H2O (2) (en = 1,2-ethylenediamine), decorated by six [Ln-(μ3-O)3-Fe] 3d–4f heterometallic clusters, have been synthesized by the hydrothermal method, and characterized by IR, element analysis, magnetic studies and the single-crystal X-ray analyses. The detailed study of the synthetic conditions reveals that the use of the organic ligands, pH value and the reaction temperature all play important roles in the synthesis of the 3d–4f heterometallic POMs. Magnetic study suggests the presence of antiferromagnetic interactions in these two compounds.
Co-reporter:Qiong Wu, Wei-Lin Chen, Ding Liu, Chang Liang, Yang-Guang Li, Shi-Wei Lin and Enbo Wang
Dalton Transactions 2011 vol. 40(Issue 1) pp:56-61
Publication Date(Web):22 Nov 2010
DOI:10.1039/C0DT00884B
By combination of heteropolymolybdates and metal–Schiff-base complexes, two new organic–inorganic hybrid compounds {Mn(salen)2(H2O)2[AlMo6(OH)6O18]}[arg]·16H2O (1) and {Mn(salen)2(H2O)2[CrMo6(OH)6O18]}[arg]·11H2O (2) (salen = N,N′-ethylene-bis(salicylideneiminate) have been successfully isolated. Compounds 1 and 2 were structurally characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. To the best of our knowledge, compounds 1 and 2 represent the first single-crystal structures of metal–Schiff-base decorated polyoxometalates (POMs) compounds. Photocatalytic experiments indicated that both 1 and 2 exhibit high catalytic activity for photodegradation of RhB with UV irradiation. In addition, the magnetic properties of 1 were also investigated.
Co-reporter:Hai Fu, Yangguang Li, Ying Lu, Weilin Chen, Qiong Wu, Jingxin Meng, Xiaolan Wang, Zhiming Zhang, and Enbo Wang
Crystal Growth & Design 2011 Volume 11(Issue 2) pp:458-465
Publication Date(Web):January 12, 2011
DOI:10.1021/cg101224r
One new polyoxometalate compound H3(Tea)(Bmim)3[P2W18O62]·3H2O (Tea = triethylamine, Bmim = 1-methyl-3-ethylimidazole) (1) and three new polyoxometalate-based metal−organic frameworks (PMOFs) CuII(Bbi)1.5(H2Bbi)2[P2W18O62] (Bbi = 1,1-(1,4-butanediyl)-bis(imidazole)) (2), CuII2.5(Mimin)(HMimin)(Bbi)3[P2W18O62]·3H2O (Mimin = methylimidazol) (3), and CuII(Bbtz)(H2Bbi)(H2Btp)[P2W18O62] (Bbtz = 1,4-bis(triazol-1-ylmethyl)benzene, Btp = 1,3-Bis(1,2,4-triazol-1-yl)propane) (4) have been synthesized under ionothermal conditions using an ionic liquid (IL) [Bmim]Br (Bmim = 1-ethyl-3-methylimidazole) as solvent. Their structures were determined by single crystal X-ray diffraction. Compound 1 possesses a one-dimensional (1D) supramolecular chain-like structure constructed from [P2W18O62]6− anions, Bmim, Tea, and water molecules. Compound 2 has a two-dimensional (2D) (6,3)-layer structure built by [P2W18O62]6− anions, copper ions, and Bbi ligands. Compounds 3 and 4 are three-dimensional (3D) PMOFs with novel (6.8.10)(4.6.83.10)(4.6.83.12) and classic (65.8)(65.8)-cds topologies, respectively. Compounds 2−4 represent the first examples of PMOFs synthesized by the ionothermal method. The successful synthesis of compounds 2−4 suggests that ionothermal synthesis will be a very promising synthetic technique for assembling new PMOFs. Additionally, the properties of the four compounds have been studied in detail.
Co-reporter:Qiuyu Li, Chunlei Wang, Mingliang Ju, Weilin Chen, Enbo Wang
Microporous and Mesoporous Materials 2011 Volume 138(1–3) pp:132-139
Publication Date(Web):February 2011
DOI:10.1016/j.micromeso.2010.09.014
Uniform zinc oxide hollow spheres with diameters of about 200–300 nm and shells composed of nanoparticles were fabricated in large scale by a one-step polyoxometalate (POM)-assisted electrochemical method at room temperature. A series of experiments demonstrated that the addition of POMs, the concentration of H2O2 and reaction time all had significant effect on the morphology of the products. The products were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The photocatalytic activity of as-prepared ZnO hollow spheres was also evaluated by using Rhodamine (RhB) as a model organic compound and the result revealed that the products showed high photocatalytic activity to degradation of Rhodamine (RhB) under UV-light illumination. Based on the evolution of the ZnO hollow spheres and the electrochemical principle, a rational formation and evolution mechanism of the products was revealed.Graphical abstractUniform zinc oxide hollow spheres with diameters of about 200–300 nm and shells composed of nanoparticles were fabricated in large scale by a one step polyoxometalates (POMs)-assisted electrochemical method at room temperature. The zinc oxide hollow spheres show high photocatalytic activity to degradation of Rhodamine (RhB) under UV-light illumination.Research highlights► A facile template-free electrochemical route is developed for rational fabrication of ZnO hollow spheres with assistance of polyoxometalates at room temperature. ► Polyoxometalates plays key role in information of the ZnO hollow spheres. ► In addition, the ZnO hollow spheres exhibit high photocatalytic activity to degradation of Rhodamine under UV-light illumination.
Co-reporter:Xiao-Jia Feng, Wei Yao, Ming-Fa Luo, Rui-Ying Ma, Hong-Wei Xie, Yang Yu, Yang-Guang Li, En-Bo Wang
Inorganica Chimica Acta 2011 Volume 368(Issue 1) pp:29-36
Publication Date(Web):15 March 2011
DOI:10.1016/j.ica.2010.12.015
Two new complexes, [Cu(bppdo)(Hbppdo)(CH3CN)3][PW12O40]·CH3CN·0.5H2O (1) and [Co(2,2′-bpdo)3]2[PWVWVI11O40]·CH3CN·2H2O (2) (bppdo = 1,3-bis(4-pyridyl)propane-N,N′-dioxide, 2,2′-bpdo = 2,2′-bipyridine-N,N′-dioxide), have been synthesized by layering MHPW12O40 salts (M = Cu2+ for 1 and Co2+ for 2) on the organic bppdo (for 1) or 2,2′-bpdo (for 2) ligands with the mixed media of acetonitrile and water at room temperature. Both complexes were fully characterized by elemental analyses, TG analyses, IR, UV–Vis, cyclic voltammetry and single-crystal X-ray diffraction. Both crystal structures exhibit the new polyoxometalate (POM)-templated supramolecular network arrays. The “host” supramolecular networks with large pores are composed of the [Cu(bppdo)(Hbppdo)(CH3CN)3] ring-connected-ring chains for 1 and the [Co(2,2′-bpdo)3] windstick-type units for 2. The “guest” Keggin-type polyoxoanions are located in the pores and dispersed between two organic layers in both complexes. Electrochemical properties of 1 and 2 were investigated and both compounds show the electrocatalytic activity towards the reduction of nitrite.Graphical abstractThe introduction of neutral flexible and chelate O-donor ligands into transition-metal-polyoxometalate systems led to the isolation of two new polyoxometalate-templated host–guest supramolecular network assemblies.Research highlights► Two types of neutral pyridine-N-oxide(PNO)-containing ligands were used to prepare new polyoxometalate(POM)-templated supramolecular network assemblies of 1 and 2. ► Both compounds show interesting host-guest structural features and ► exhibit the electrocatalytic activities towards the reduction of nitrite.
Co-reporter:Tianzhan Zhang, Ying Lu, Weilin Chen, Xin Wang, Shuang Yao, Zhiming Zhang, Enbo Wang
Inorganica Chimica Acta 2011 Volume 365(Issue 1) pp:377-383
Publication Date(Web):15 January 2011
DOI:10.1016/j.ica.2010.09.047
Two new organic–inorganic hybrid compounds, {[Cu(2,2′-bipy)2]2(Hbpy)[α-AlW12O40]}·H2O (1) and {[H2en][CuI(4,4′-bipy)]3(α-AlW12O40)}·4H2O (2) (2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine, py = pyridine, en = ethylene dimine) based on Keggin-type α-[AlW12O40]5− polyoxoaions and transition-metal organoamine subunits, have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TG), and single-crystal X-ray diffraction. In addition, the electrochemical properties and photocatalytic activity of compound 1 were studied. The structural analysis reveals that 1 shows a 1D infinite chain structure constructed from [α-AlW12O40]5− polyoxoanions and {[CuII(2,2′-bipy)2][CuII(2,2′-bipy)(py)]}4+ fragments, in which the remarkable aspect is that [α-AlW12O40]5− polyoxoanion is modified in a fascinating symmetrical mode. Compound 2 displays an unprecedented 2D extended structure constructed from [α-AlW12O40]5− polyoxoanions and 4,4′-bipy-CuI-4,4′-bipy linear chains, in which three – chain belts formed by three linear chains arranged Cu parallel connect alternately with [α-AlW12O40]5− polyoxoanions. As far as we know, compounds 1 and 2 represent the first 1D and 2D extended hybrid materials constructed from 3d transition metals and polyoxotungstoaluminates linked through covalent bonds.Two new organic–inorganic hybrid compounds with Keggin-type α-[AlW12O40]5− polyoxoaion and transition-metal organoamine subunits, namely, {[Cu(2,2′-bipy)2]2(Hbpy)[α-AlW12O40]}·H2O (1) and {[H2en][CuI(4,4′-bipy)]3(α-AlW12O40)}·4H2O (2) have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TG), and single-crystal X-ray diffraction. The electrochemical properties and photocatalytic activity of compound 1 have been investigated.
Co-reporter:Mingliang Ju, Qiuyu Li, Enbo Wang
Materials Letters 2011 Volume 65(Issue 3) pp:507-509
Publication Date(Web):15 February 2011
DOI:10.1016/j.matlet.2010.10.081
A facile template-free solvothermal approach was applied to synthesize olive-like ZnO nanoparticles with an average diameter of about 300 nm and an average length of about 600 nm. XRD, TEM, SEM, SAED, EDX and PL spectra were employed to characterize the crystal phase, morphologies, the chemical compositions, and optical properties of the ZnO nanostructure. The experimental results showed the as-obtained ZnO was single-crystalline nanostructure and the concentration of CH3COO− solution played a key role in controlling the morphology of ZnO. The growth mechanism of ZnO was tentatively investigated. Besides, the olive-like ZnO nanoparticles exhibit a very strong ultraviolet emission centered at 383 nm and a weak green luminescence emission at around 522 nm.
Co-reporter:Xue-Song Zang, Qiong Wu, Wei-Lin Chen, Hua-Qiao Tan, Yang-Guang Li, En-Bo Wang
Inorganic Chemistry Communications 2011 Volume 14(Issue 4) pp:590-593
Publication Date(Web):April 2011
DOI:10.1016/j.inoche.2011.01.031
We report a Keplerate-type polyoxometalate Na18K8[{Mo6O21(H2O)3(SO4)}12(Fe(H2O)2)30]·ca. 67 H2O (1), which is composed of 12 pentagonal {(Mo)Mo5} units and 30 [Fe(H2O)2]3+ linkers. This giant heterometal Keplerate-type cluster is supported by SO42− and display interesting topologies, which are connected by two kinds of Na+ cations (mononuclear and binuclear Na+ cations) to form three-dimensional (3-D) open-framework. The compound was characterized by the elemental analysis, thermogravimetry, spectroscopic methods (IR and UV/Vis), bond valence sum (BVS) calculations, X-ray photoelectron spectroscopy (XPS) and single crystal X-ray structure analysis. The photocatalytic property of compound 1 has been investigated, which shows a good photocatalyst for the degradation of RhB.The Keplerate cluster is composed of 12 slightly domed (virtual C5v symmetry), {(Mo)Mo5} pentagonal units connected by 30 [FeIII(H2O)2]3+ linker groups. The spherical shell encapsulates 12 heavily disordered tridentate sulfate groups. And the discrete polyanionic capsule contains 20 (Mo3Fe3O6) pores, the eight close association of the K+ ions and twelve Na+ ions to the twenty {Mo3Fe3O6} hexagonal pores reminiscent of K+-specific and Na+-specific crown ethers respectively, and other Na+ ions (mononuclear and binuclear Na+ ions) play the part of linking the discrete capsules to the three-dimensional (3-D) open-framework.Research Highlights► Supported by SO42–. ► Displays interesting 3-D topologies. ► A good photocatalyst for degradation of RhB.
Co-reporter:Qiuyu Li, Weilin Chen, Mingliang Ju, Lin Liu, Enbo Wang
Journal of Solid State Chemistry 2011 Volume 184(Issue 6) pp:1373-1380
Publication Date(Web):June 2011
DOI:10.1016/j.jssc.2011.04.006
With the assistance of Keggin-type polyoxometalate, ZnO hollow microspheres with mesoporous shells were synthesized via a simple solvothermal approach without any templates and surfactants. The observations of morphology and structure performed by field emission scanning electronic microscopy and transmission electron microscopy indicated that the shells of the ZnO hollow spheres were built from nanosheets which were composed of nanoparticles. The transformation of structure and composition of samples were investigated by X-ray diffraction, X-ray photoelectron spectrometry and fourier transform infrared absorption spectroscopy. The formation mechanism of the hollow spheres is proposed based on time-dependent experimental results. The ZnO hollow microspheres exhibited a high photocatalytic activity for decolorization of Rhodamine B under ultraviolet irradiation.Graphical AbstractZnO hollow spheres with mesporous shells were synthesized by an one-pot polyoxometalate-assisted solvothermal route. The ZnO hollow microspheres exhibited a high photocatalytic activity for decolorization of Rhodamine B (RhB) under UV irradiation.Highlights► ZnO hollow microspheres were synthesized via a solvothermal route with polyoxometalate. ► The polyoxometalate was vital for the formation of the hollow microspheres. ► The ZnO hollow microspheres exhibited excellent photocatalytic activity of Rhodamine B.
Co-reporter:Xiao-Lan Wang;Ying Lu;Jing-Xin Meng;Hai Fu
Transition Metal Chemistry 2011 Volume 36( Issue 2) pp:201-206
Publication Date(Web):2011 March
DOI:10.1007/s11243-010-9454-y
Three new organic–inorganic hybrid complexes based on the Wells–Dawson polyoxoanion, namely (H2bpp)[Ni2(bpp)2(H2O)4(P2W18O62)]·H2O 1, [Cu6(Hbpy)6(bpy)3(P2W18O62)2]·2H2O 2 and (Him)5[Cu(im)2(P2W18O62)]·4H2O 3 [bpp = 1,3-bis (4-pyridyl) propane, bpy = 4,4′-bipyridine, im = imidazole] have been synthesized and characterized. Complex 1 exhibits a three-dimensional (6, 3)-connected framework with anatase topology constructed from [α-P2W18O62]6− clusters and [Ni(bpp)]2+ fragments. Each [α-P2W18O62]6− anion links to six nickel atoms through six terminal oxygen atoms from four polar and two equatorial WO6 octahedra, which shows a novel coordination mode of a Wells–Dawson cluster with a transition-metal atom. Complex 2 displays an interesting one-dimensional double-chain structure built from [α-P2W18O62]6− clusters and [Cu2(bpy)(Hbpy)2]2+ fragments. To our knowledge, complex 2 represents the first double-chain organic–inorganic hybrid complex based on a Wells–Dawson-type cluster. Complex 3 possesses a one-dimensional zigzag chain structure constructed from [α-P2W18O62]6− anions and [Cu(im)2]+ units through weak Cu···O interactions.
Co-reporter:Bao-Wang Chen;Wei-Lin Chen;Yang-Guang Li
Journal of Cluster Science 2011 Volume 22( Issue 1) pp:73-85
Publication Date(Web):2011 March
DOI:10.1007/s10876-011-0360-z
Two new tungstoantimonates Na4H2[{Co(H2O)3}2Co(H2O)2W(H2O)2 (B-β-SbW9O33)2]·33H2O (1) and H4[Mn2(H2O)8Mn3.5(H2O)7W0.5(H2O)(B-β-SbW9O33)2]·20H2O (2) have been obtained by the routine synthetic reactions in the aqueous solutions and characterized by elemental analysis, IR, TG analysis. Compound 1 is built from the sandwich-type polyoxoanions [{Co(H2O)3}2Co(H2O)2W(H2O)2(B-β-SbW9O33)2]6−, linked by Na+ cations to construct a 1-D chain-like structure. Compound 2 shows an interesting 2-D structure built up from sandwich-type anions [Mn3.5(H2O)7W0.5(H2O)(B-β-SbW9O33)2]8− linked by additional Mn2+ ions, which represents the first example of pure inorganic 2-D structure based on the Mn-containing sandwich-type polytungstoantimonate clusters. The electrochemical and photochemical catalysis activities of compounds 1 and 2 have also been investigated.
Co-reporter:HuaQiao Tan;WeiLin Chen;Ding Liu;AiXue Yan;EnBo Wang
Science China Chemistry 2011 Volume 54( Issue 9) pp:
Publication Date(Web):2011 September
DOI:10.1007/s11426-011-4340-9
Two new compounds with microporous Co3[MnMo9O32]·15H2O (1) and Cu3[MnMo9O32]·15H2O (2) have been synthesized, and characterized by IR, element analysis, TG and single-crystal X-ray analysis. The structure analyses reveal that compounds 1 and 2 are isostructural. In crystal, the Waugh-type polyoxoanions [MnMo9O32]6− are connected by Co2+ or Cu2+ cations to a 3D open-framework, which possesses channels along the [1 2 2] direction of approximately 8.27 × 11.97 Å. The photocatalytic performances of compounds 1 and 2 for photodegradation of RhB with UV irradiation have been studied, which show a good photocatalytic activity for photodegradation of RhB.
Co-reporter:Shiwei Lin, Wenli Liu, Yangguang Li, Qiong Wu, Enbo Wang and Zhiming Zhang
Dalton Transactions 2010 vol. 39(Issue 7) pp:1740-1744
Publication Date(Web):21 Dec 2009
DOI:10.1039/B905079E
Ionothermal synthesis was applied to the formation of polyoxometalates (POMs) and two new compounds [EMIM]8Na9[WFe9(µ3-O)3(µ2-OH)6O4H2O(SiW9O34)3]·7H2O (1, [EMIM]8Na9[1a]·7H2O, EMIM = 1-ethyl-3-methylimidazolium) and [EMIM]4[SiMo12O40]·12H2O (2), have been successfully produced in the ionic liquid (IL) [EMIM]4Br. They were characterized by single-crystal X-ray diffraction, elemental analysis, UV-vis, IR and TG analysis. Furthermore, the magnetic properties of 1 and the electrochemical properties of 2 were studied. 1 is a high-nuclear transition metal substituted polyoxometalate (TMSP) and the unprecedented polyoxoanion of 1a is composed of three [α-SiW9O34]10− Keggin moieties connected by a {WFe9} cluster core. 2 is a heteropolyoxometalate with the polyoxoanion of α-Keggin type.
Co-reporter:Hua-Qiao Tan, Wei-Lin Chen, Ding Liu, Yang-Guang Li and En-Bo Wang
CrystEngComm 2010 vol. 12(Issue 12) pp:4017-4019
Publication Date(Web):16 Aug 2010
DOI:10.1039/C0CE00104J
A new diphosphonate-functionalized polyoxomolybdate L,D-(NH4)6{MoV2O4[(MoVI2O6)NH3CH2CH2CH2C(O)(PO3)2]2}·10H2O (1) has been synthesized by the reaction of alendronic acid with {Mo2O4(H2O)6}2+ fragments. In the structure, a restriction of “folding” alkyl induced chiral polyoxometalate has been observed.
Co-reporter:Ding Liu, Hua-Qiao Tan, Wei-Lin Chen, Yang-Guang Li and En-Bo Wang
CrystEngComm 2010 vol. 12(Issue 7) pp:2044-2046
Publication Date(Web):11 May 2010
DOI:10.1039/C001160F
The classical Dawson-type racemic polyoxoanions [P2Mo18O62]6− have been separated in aqueous solution with L,D-histidine, respectively. Two enantiomerically pure compounds: H3(L-HC6H9N3O2)3[P2Mo18O62]·20H2O (1a), H3(D-HC6H9N3O2)3[P2Mo18O62]·20H2O (1b), have been synthesized.
Co-reporter:Lan-Cui Zhang, Shu-Li Zheng, Han Xue, Zai-Ming Zhu, Wan-Sheng You, Yang-Guang Li and Enbo Wang
Dalton Transactions 2010 vol. 39(Issue 14) pp:3369-3371
Publication Date(Web):22 Feb 2010
DOI:10.1039/B925822A
The reaction of Cl3Sn(CH2)2COOCH3, [H2P2W12O48]12− and WO42− in acetate buffer solution led to the hydrolysis of estertin into a carboxyethyltin group and the assembly of a new tetra(organotin)-decorated boat-like polyoxometalate.
Co-reporter:Shuang Yao, Zhiming Zhang, Yangguang Li and Enbo Wang
Dalton Transactions 2010 vol. 39(Issue 16) pp:3884-3889
Publication Date(Web):11 Mar 2010
DOI:10.1039/B921261B
Reactions of hexavacant polyoxotungstates [H2P2W12O48]12− ({P2W12}) with transition-metal (TM), and alkali-metal ions lead to the isolation of two hexa-TM-containing polyoxotungstates Na15[Na3⊂{M(H2O)4}6{WO(H2O)}3(P2W12O48)3]·xH2O (M = Co2+, x = 109 for 1; M = Ni2+, x = 110 for 2). Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 both crystallized in the orthorhombic system, space group Cmcm, with lattice constants a = 21.353(3) Å, b = 32.114(3) Å, c = 33.848(4) Å, for 1; a = 21.643(6) Å, b = 31.870(6) Å, c = 33.861(7) Å for 2. Polyoxoanions [Na3⊂{M(H2O)4}6{WO(H2O)}3(P2W12O48)3]15− in 1 and 2 exhibit a crown-type structure composed of a [{WO(H2O)}3(P2W12O48)3]18- (abbreviated as {P6W39}) shell encapsulating six TM ions and three Na+ cations. Polyoxoanions 1 and 2 represent the first hexa-TM-containing {P2W12}-based trimeric POMs, which offer new examples with the potentially aqua-ligand-induced capability of “trapping” metal ions in the {P6W39} shell. Electrocatalytic studies show that compounds 1 and 2 display electrocatalytic activity to reduce nitrite.
Co-reporter:Shuang Yao, Zhiming Zhang, Yangguang Li, Ying Lu, Enbo Wang and Zhongmin Su
Crystal Growth & Design 2010 Volume 10(Issue 1) pp:135
Publication Date(Web):December 1, 2009
DOI:10.1021/cg900745z
Reactions of hexavacant polyoxotungstate [H2P2W12O48]12− ({P2W12}) with transition-metal and lanthanide-metal cations assisted with organic molecules (tartrate or dimethylammonium chloride) lead to the isolation of two polyoxotungstates: K3Na8[K3⊂{GdMn(H2O)10}{HMnGd2(Tart)O2(H2O)15}{P6W42O151(H2O)7}]·44H2O (1) and K3Na10[K3⊂{GdCo(H2O)11}2{P6W41O148(H2O)7}]·43H2O (2). Single-crystal X-ray diffraction analyses reveal that both 1 and 2 contain a crown-type polyoxoanion shell [{WO(H2O)}3(P2W12O48)3]30− ({P6W39}), which consists of three {P2W12} units connected by three {WO(H2O)} linkers. Compound 1 has a two-dimensional porous framework constructed from 3d-4f cluster-containing {P6W39} aggregates and mixed 3d and 4f linkers. Compound 2 exhibits a one-dimensional chain-like structure composed of di-Co-containing {P6W39} aggregates and {Gd(H2O)7}3+ bridging units. Magnetic studies of compounds 1 and 2 indicate that antiferromagnetic interactions exist in these two compounds.
Co-reporter:Xiao-Lan Wang, Yang-Guang Li, Ying Lu, Hai Fu, Zhong-Min Su, and En-Bo Wang
Crystal Growth & Design 2010 Volume 10(Issue 10) pp:4227
Publication Date(Web):September 13, 2010
DOI:10.1021/cg100783w
With the use of a flexible N-donor ligand 1,3-bis(4-pyridyl)propane (bpp), a new porous framework with Wells-Dawson clusters as nodes and Ni2+ ions as linkers, [Ni(bpp)(H2O)2]3[P2W18O62]·∼24H2O (1), has been successfully obtained. Topological analysis indicates that 1 possesses a perovskite structure. As a porous framework, 1 displays adsorption behavior toward H2O and CH3OH.
Co-reporter:Huaqiao Tan, Weilin Chen, Ding Liu, Yangguang Li and Enbo Wang
Dalton Transactions 2010 vol. 39(Issue 5) pp:1245-1249
Publication Date(Web):23 Nov 2009
DOI:10.1039/B912321K
Two new cantilever-type polyoxometalates Na5(NH4){VIV[(Mo2O6)CH3C(O)(PO3)2]2}·13H2O (1) and (NH4)4{VIV[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]2}·6H2O (2) have been synthesized and characterized by IR spectroscopy, UV-visible spectroscopy, elemental analysis, TG analysis, XPS, 31P NMR and single-crystal X-ray diffraction. The structure analysis reveals that the diphosphonate, hydroxyethylidene diphosphonic acid and alendronic acid as the scaffolds, have been grafted on the “S”-shaped polyoxoanions 1 and 2 respectively. The alkyl groups of the diphosphonates like arms hanged on the polyoxoanions form the cantilever-type polyoxometalates.
Co-reporter:Shi-Ming Wang, Wei-Lin Chen, En-Bo Wang, Yang-Guang Li, Xiao-Jia Feng, Lin Liu
Inorganic Chemistry Communications 2010 Volume 13(Issue 8) pp:972-975
Publication Date(Web):August 2010
DOI:10.1016/j.inoche.2010.05.010
Three new polyoxometalate-based hybrids {[(CH3)3N(CH2)2OH]2(H3O)}[Na2(H2O)6][IMo6O24]·H2O 1 , {Na2[(CH3)3N(CH2)2OH]4}[Al(OH)6Mo6O18]2·8NH2CONH2·4H2O 2 and {Na6(H2O)18[(CH3)3N(CH2)2OH]2(CON2H5)2}[NaMo7O24]2·4NH2CONH2·H2O 3 were successfully synthesized in the choline chloride/urea deep eutectic mixture at room temperature. Reactant quantities of water presents in the nonaqueous eutectic mixture solvent may influence the structure of the products. The three compounds are fully characterized by elemental analyses, IR, UV–vis, TG analyses, power X-ray diffraction and single-crystal X-ray diffraction. The photocatalytic properties of 1 and 2 are investigated.Three new polyoxometalate-based hybrids have been synthesized in choline chloride/urea eutectic mixture at room temperature. Reactant quantities of water influence the final structure of the products.
Co-reporter:Guoying Sun, Qiuyu Li, Rui Xu, Jianmin Gu, Mingliang Ju, Enbo Wang
Journal of Solid State Chemistry 2010 Volume 183(Issue 11) pp:2609-2615
Publication Date(Web):November 2010
DOI:10.1016/j.jssc.2010.08.039
Pt nanospheres with an average diameter of 60±10 nm have been successfully synthesized at room temperature through a facile polyoxometalate(POM)-assisted process. Characterization by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) clearly showed that these Pt nanospheres consisted of 2–7 nm Pt nanodots. During the formation of such unique nanostructures, POMs were found to serve as both catalyst and stabilizer. The size of the as-synthesized Pt nanospheres could be controlled solely by adjusting the molar ratio of POMs to H2PtCl6. A possible formation mechanism based on POMs-mediated electron transfer from ascorbic acid (AA) to PtCl62− and AA-assisted aggregation was tentatively proposed to rationalize the formation of such nanostructures. Importantly, these specific Pt nanospheres exhibited good electrocatalytic activity towards the oxidation of methanol, making them promising for applications in direct methanol fuel cells.Large-scale Pt nanospheres were synthesized through a polyoxometalate-assisted process, and exhibited good electrocatalytic activity towards the oxidation of methanol, making them promising for applications in fuel cells.
Co-reporter:Zhiming Zhang, Jia Liu, Yangguang Li, Shuang Yao, Enbo Wang, Xinlong Wang
Journal of Solid State Chemistry 2010 Volume 183(Issue 1) pp:228-233
Publication Date(Web):January 2010
DOI:10.1016/j.jssc.2009.10.016
Two entangled compounds [(bpy)6CuI6Cl3(MoVW5O19)] (1) and [(bpy)7CuI7Cl2(BW12O40)]·H2O (2) (bpy=4,4′-bipyridine), have been successfully synthesized under hydrothermal conditions and characterized by element analysis, IR spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectroscopy, and single crystal X-ray diffraction analyses. Compound 1 represents the first eight-connected self-penetrating network constructed from cuprous chloride clusters [Cu6Cl3] and Lindquist-type polyoxoanions. Compound 2 exhibits an interesting fivefold interpenetrating network consisting of Keggin polyoxoanions and Cu+-metal–organic framework. Crystal data of the two compounds are following: 1, triclinic, P1¯, a=11.502(2) Å, b=13.069(3) Å, c=13.296(3) Å, α=90.55(3)°, β=113.74(3)°, γ=110.48(3)°, Z=1; 2, triclinic, P1¯, a=12.341(3) Å, b=13.119(3) Å, c=15.367(3) Å, α=99.12(3)°, β=90.53(3)°, γ=104.49(3)°, Z=1.Compound 1 is the POM-based unprecedented eight-connected self-penetrating organic–inorganic hybrid network constructed from the cuprous chloride clusters [Cu6Cl3], Lindquist-type polyoxoanions [MoVW5O19], and the 4,4′-bipyridine ligands.
Co-reporter:Shuang Yao, Zhiming Zhang, Yangguang Li, Enbo Wang
Inorganica Chimica Acta 2010 Volume 363(Issue 10) pp:2131-2136
Publication Date(Web):20 June 2010
DOI:10.1016/j.ica.2010.03.003
Self assembly of NaVO3, Na2MoO4·2H2O and NiCl2·6H2O with the assistance of organic liginds under hydrothermal conditions results in two molybdovanadates [Ni(enMe)2]4{[Ni(enMe)2(H2O)]2[Ni(enMe)2][(VVMoVI8V4IVO40)(VIVO)2]2}·10H2O (1) and [Ni(enMe)2]5{[Ni(enMe)2]2[(VVMoVI4MoV4V4IVO40)(VIVO)4]2}·2H2O (2), (enMe = 1,2-diaminopropane), which have been characterized by single crystal X-ray diffraction analysis, IR spectroscopy, and elemental analysis. Both of the two compounds exhibit dumbbell-like structures constructed from capped polyoxomolybdovanadates and [Ni(enMe)2]2+ complexes. Polyoxoxanion 1 is composed of two bicapped Keggin-type anions [(VVMo8V4IVO40)(VIVO)2]7−, one [Ni(enMe)2]2+ bridging fragment and two decorated nickel(II) complexes. Polyxoxanion 2 consists of two tetracapped molybdenum–vanadium polyoxoanions [(VVMoVI4MoV4V4IVO40)(VIVO)4]7−, one [Ni(enMe)2]2+ bridging fragment and a nickel(II) decorated fragment. Polyxoxanions 1 and 2 are further linked to form three-dimensional supramolecular networks through extensive hydrogen bonding interactions. In addition, photocatalysis properties of these two compounds have been investigated.Two polyoxoanions, which exhibit dumbbell-like structures construct from capped polyoxomolybdovanadates and [Ni(enMe)2]2+ complexes, have been successfully synthesized. Compound 1 represents the first dumbbell-like polyoxomolybdovanadate composed of the bicapped Keggin polyoxoanions linked by inorganic–organic hybrid complex. Compound 2 is the first dumbbell-like polyoxomolybdovanadate based on the tetracapped polyoxoanions.
Co-reporter:Shi-Ming Wang, Yun-Wu Li, Xiao-Jia Feng, Yang-Guang Li, En-Bo Wang
Inorganica Chimica Acta 2010 Volume 363(Issue 7) pp:1556-1560
Publication Date(Web):20 April 2010
DOI:10.1016/j.ica.2009.12.012
Co-reporter:Huaqiao Tan, Weilin Chen, Ding Liu, Yangguang Li, Enbo Wang
Inorganic Chemistry Communications 2010 Volume 13(Issue 11) pp:1354-1356
Publication Date(Web):November 2010
DOI:10.1016/j.inoche.2010.07.035
A new polyoxoniobate with NbIVO8 center and Cu24 core K12Na[H23NbIVO8Cu24(Nb7O22)8]·81H2O (1) has been synthesized by the reaction of K7HNb6O19·13H2O with Cu(CH3COO)2·H2O in the presence of NbIVO2, and characterized by elemental analyses, IR spectrum, TG analysis, magnetic property and single-crystal X-ray diffraction. The structure analysis reveals that the polyoxoanion is composed of one NbIVO8 cube-like unit, 24 copper centers and eight [Nb7O22]9− fragments. The magnetic investigation shows that compound 1 exhibits antiferromagnetic interactions.A new polyoxoniobate with NbIVO8 center and Cu24 core K12Na[H23NbIVO8Cu24(Nb7O22)8]·81H2O (1) has been synthesized. The polyoxoanion is composed of one NbIVO8 cube-like unit, 24 copper centers and eight [Nb7O22]9− fragments.
Co-reporter:Yan-Fei Qi, Chun-Ping Lv, Yang-Guang Li, En-Bo Wang, Juan Li, Xiu-Ling Song
Inorganic Chemistry Communications 2010 Volume 13(Issue 3) pp:384-387
Publication Date(Web):March 2010
DOI:10.1016/j.inoche.2009.12.029
A new cobalt–vanadium composite solid, Co3(btx)5(H2O)V8O231 (btx = 1,4-bis(triazol-1-ylmethyl)benzene) has been synthesized. Compound 1 exhibits a novel three-dimensional (3D) 4, 6-connected self-catenated net constructed from novel [V8O23]6− building blocks and the {Co3(btx)5(H2O)2}6+ 3D metal–organic cation polymer. The magnetic study and electronic property of 1 have also been investigated.A new cobalt–vanadium composite solid, Co3(btx)5(H2O)V8O23 (btx = 1,4-bis(triazol-1-ylmethyl)benzene) was obtained, exhibiting a novel three-dimensional (3D) 4, 6-connected self-catenated net constructed from novel [V8O23]6− building blocks and the {Co3(btx)5(H2O)2}6+ 3D metal–organic cation polymer.
Co-reporter:Mingliang Ju, Qiuyu Li, Jianmin Gu, Rui Xu, Yangguang Li, Xinlong Wang, Enbo Wang
Materials Letters 2010 Volume 64(Issue 5) pp:643-645
Publication Date(Web):15 March 2010
DOI:10.1016/j.matlet.2009.12.034
With the assistance of polyoxometalate (POM), ZnO spindles have been successfully synthesized in ionic liquid by electrochemical deposition. The as-obtained ZnO spindles are composed of small nanoparticles and have a porous structure with a specific surface area of 97.95 m2/g. Parallel experiments were also performed to understand the formation mechanism of the spindle-like ZnO. The experimental results showed that POM played a key role for the formation of the spindle-like ZnO. A possible formation mechanism was also proposed. The photoluminescence spectrum of the ZnO spindles exhibits a strong ultraviolet emission at 390 nm and a very weak visible emission at around 560 nm.
Co-reporter:Qiong Wu, Yang-Guang Li, Yong-Hui Wang, Zhi-Ming Zhang, En-Bo Wang
Inorganic Chemistry Communications 2010 Volume 13(Issue 1) pp:66-69
Publication Date(Web):January 2010
DOI:10.1016/j.inoche.2009.10.018
A new sandwich-type polyoxometalate (POM) K12Na1[(HPW7O28)2Mn]·17.5H2O (1) has been synthesized and characterized by elemental analysis, IR, TG, UV as well as single-crystal X-ray diffraction analysis. Compound 1 represents the first sandwich-type POM constructed by the penta-lacunary heptatungstophosphate [HPW7O28]8− moieties. Moreover, compound 1 exhibits good electrocatalytic properties to reduce the nitrite.The first heptatungstophosphate-based sandwich-type polyoxometalate K12Na[(HPW7O28)2Mn]·17.5H2O has been synthesized, exhibiting good electrocatalytic properties to reduce the nitrite.
Co-reporter:Rui Xu, Guoying Sun, Qiuyu Li, Enbo Wang, Jianmin Gu
Solid State Sciences 2010 Volume 12(Issue 10) pp:1720-1725
Publication Date(Web):October 2010
DOI:10.1016/j.solidstatesciences.2010.06.026
A bicontrollable drug release system was developed by layer-by-layer assembly of poly(allylamine hydrochloride) (PAH)/sodium poly(styrene sulfonate) (PSS) multilayers onto a Fe3O4/SiO2 composite core. The saturated magnetization of this system reaches up to 38.6 emu/g at RT, making targeting easily controlled by an external magnetic field. Meanwhile, the packing of the polyelectrolyte multilayers is sensitive to pH values, generating a pH-switch on-off mode for the release of loaded drugs. In this specific case, the release of a chemotherapeutic polyoxometalate K7Ti2W10PO40·6H2O (PM–19) was tested. Transmission electron microscopy (TEM) was used to examine the nanostructure of the composite drug release system. UV–vis absorption was used to monitor the drug release. Fourier transform infrared (FTIR), Powder X–ray diffraction, and Elemental analyses were used to study the composition of tested systems. The structure and composition of the composite system was also studied using magnetism measurement and nitrogen adsorption–desorption.
Co-reporter:Wei-Lin Chen, Bao-Wang Chen, Hua-Qiao Tan, Yang-Guang Li, Yong-Hui Wang, En-Bo Wang
Journal of Solid State Chemistry 2010 Volume 183(Issue 2) pp:310-321
Publication Date(Web):February 2010
DOI:10.1016/j.jssc.2009.11.016
Employing the ionothermal synthesis approach, three new transition-metal-containing polyoxotungstate hybrids: [Dmim]2Na3[SiW11O39Fe(H2O)]·H2O (Dmim=1,3-Dimethylimidazole) (1), [Emim]9Na8[(SiW9O34)3{Fe3(μ2-OH)2(μ3-O)}3(WO4)]·0.5H2O(Emim=1-Ethyl-3-meth-ylimidazole) (2) and [Dmim]2[HMim]Na6[(AsW9O33)2{MnIII(H2O)}3]·3H2O (Dmim=1,3-Dimethylimidazole; Mim=1-Methylimidazole) (3) have been synthesized in 1-ethyl-3-methyl imidazolium bromide ([Emim]Br) ionic liquids (ILs). Compound 1 possesses a 3-D open framework constructed from the mono-ironIII-substituted α-Keggin-type anion and the organic cations [Dmim]+ through the hydrogen bond interactions. Compound 2 contains a [{FeIII3(μ2-OH)2(μ3-O)}3(μ4-WO4)] cluster surrounded by three [SiW9O34]10− ligands, eight sodium cations and nine dissociative [Emim]+ cations around the polyoxoanion. The polyoxoanion of 3 consists of a high-valent trinuclear-manganese (III)-substituted sandwiching polyoxoanion based on the [α-AsW9O33]9− units. All the compounds are characterized by elemental analyses, IR, UV–vis spectra, TG-DTA and XRD analyses. The XPS and EPR spectra of MnIII in 3 were studied. The photocatalytic and electrocatalytic properties, as well as the stabilities of 1–3 were also investigated.Three new transition-metal-containing polyoxotungstate hybrids were synthesized successfully under the ionothermal condition, which proves that the ionothermal synthesis is a suitable synthetic method for different kinds of polyoxometalates.
Co-reporter:Wei-Lin Chen;Enbo Wang
Journal of Cluster Science 2010 Volume 21( Issue 2) pp:67-68
Publication Date(Web):2010 June
DOI:10.1007/s10876-010-0326-6
Co-reporter:Hua-Qiao Tan;Wei-Lin Chen;Ding Liu
Journal of Cluster Science 2010 Volume 21( Issue 2) pp:147-154
Publication Date(Web):2010 June
DOI:10.1007/s10876-010-0313-y
A new molybdophosphate (NH4)8{Mo2VO4[(Mo2VIO6)CH3C(O)(PO3)2]2}·14H2O (1), has been synthesized by the reaction of {Mo2VO4(H2O)6}2+ fragments with 1-hydroxyethylidenediphosphonate (hedp HOC(CH3)(PO3H2)2), and it is characterized by 31P NMR, IR, UV, element analysis, TG and single-crystal X-ray analysis. The structure analysis reveals that the polyoxoanion can be described as two {(Mo2VIO6)(CH3C(O)(PO3)2} units connected by a {Mo2VO4}2+ moiety. In the structure, the six Mo atoms are arranged into a new “W-shaped” structure, which represents a new kind of molybdophosphate.
Co-reporter:Zhi-Ming Zhang ; Shuang Yao ; Yang-Guang Li ; Rodolphe Clérac ; Ying Lu ; Zhong-Min Su
Journal of the American Chemical Society 2009 Volume 131(Issue 41) pp:14600-14601
Publication Date(Web):September 28, 2009
DOI:10.1021/ja903776h
Protein-sized chiral Fe168 cages with NbO-type topology were successfully prepared by the introduction of l- and d-tartrate ligands into the Fe3+/formate/Na+ systems exhibiting alcohol-guest sorption properties.
Co-reporter:Qiong Wu, Yang-Guang Li, Yong-Hui Wang, Rodolphe Clérac, Ying Lu and En-Bo Wang
Chemical Communications 2009 (Issue 38) pp:5743-5745
Publication Date(Web):03 Sep 2009
DOI:10.1039/B909246C
The introduction of [Mn(salen)(H2O)]2(ClO4)2·H2O ({MnIII2}) into the polyoxometalate (POM) systems Na3[XMo6(OH)6O18] (X = Al and Cr) led to the isolation of new {MnIII2}–POM composite materials with single-molecule magnetic behaviour.
Co-reporter:Jing-Xin Meng, Ying Lu, Yang-Guang Li, Hai Fu and En-Bo Wang
Crystal Growth & Design 2009 Volume 9(Issue 9) pp:4116-4126
Publication Date(Web):July 24, 2009
DOI:10.1021/cg900352e
Eight polyoxometalate (POM)-based frameworks were synthesized under hydrothermal conditions, using different octamolybdate isomers (Mo8) and copper-organic fragments or organic units in the presence of different bases. These compounds are named as [CuI(bix)][(CuIbix)(δ-Mo8O26)0.5] (1), H(CuIbix)[(CuIbix)2(β-Mo8O26)]·2H2O (2), H3[CuI(bix)2(β-Mo8O26)0.5](β-Mo8O26)0.5·2H2O (3), (H2bix)2(β-Mo8O26)0.5(β-Mo8O26)0.5·H2O (4), (H2bix)[(Hbix)2(γ-Mo8O26)]·2H2O (5), H2bix(γ-Mo8O26)0.5·H2O (6), [CuI(bpp)][CuI(bpp)(α-Mo8O26)0.5]·H2O (7), and [(H2bpp)2(β-Mo8O26)] (8) [bix = 1,4-bis(imidazole-1-ylmethyl)benzene, bpp = 1,3-bis(4-pyridyl)propane]. Their structures were determined by single-crystal X-ray diffraction. In compounds 1 and 2, four copper cations are linked by octamolybdate isomers to generate a 2D layer with (4,4) sheet, which is pillared by bix ligands to form a 3D (4,4)-connected framework with (64·82)(84·122) and (62·81)2(62·82·102) topologies, respectively. With the peneation of the copper-organic polymeric chains, a 3D polythreaded framework was formed. Compound 3 has a 3D supramolecular network based upon (β-Mo8O26)4− anions and copper-organic units, with guest (β-Mo8O26)4− anions included. In compound 4, a 3D supramolecular arrangement is constructed by the hydrogen-bond interactions between (β-Mo8O26)4− polyanions from different 2D structures and bix ligands. Compound 5 exhibits a unique bisupported structure built from Mo−N covalent bonds between (γ-Mo8O26)4- anions and bix ligands. This compound represents a rare example of organic-molecule-functionalized POM clusters that can be synthesized under hydrothermal conditions. In compound 6, a 3D supramolecular net is generated by hydrogen bonding interactions among water molecules, oxygen atoms of octamolybdate and nitrogen atoms of bix ligands. In compound 7, the bpp ligands link Cu cations and (α-Mo8O26)4− anions to generate a 1D ladder-like chain. [Cu(bpp)]22+ fragments further connect with (α-Mo8O26)4- anions from different chains to form a 2D (3,4)-connected layer with (4281)(6184101) topology. Compound 8 also has 3D supramolecular framework based on C−H···O hydrogen bonds between bpp and (β-Mo8O26)4− polyoxoanions. It is proposed that the different basicity, steric hindrance, and reducing strength of the bases used are the key factors in generating different Mo8 isomers in the reaction process, and thus the different frameworks as seen in 1−8. A ligand synergetic effect is also taken into account to explain the presence of the same Mo8 isomers in 7 and 8, which were synthesized with different bases. IR, TG, and electrochemistry study were performed to further characterize these compounds.
Co-reporter:Guoying Sun, Yaping Chang, Siheng Li, Qiuyu Li, Rui Xu, Jianmin Gu and Enbo Wang
Dalton Transactions 2009 (Issue 23) pp:4481-4487
Publication Date(Web):01 Apr 2009
DOI:10.1039/B901133A
Two efficient pH-responsive oral delivery systems have been fabricated through a dative bonding between the amino-functionalized mesoporous silica materials, including MCM-41-type mesoporous silica nanospheres (MMSNs) and bimodal mesoporous silica microspheres (BMSMs), and an antitumour-active polyoxometalate K8H2[Ti(H2O)]3SiW9O34 (Ti3SiW9). The Ti3SiW9 loaded in the pores of MMSNs and BMSMs are up to 23.72 wt% and 28.69 wt% at pH 6.5, respectively. Both delivery systems reveal an increase of Ti3SiW9 release under mildly alkaline conditions, while zero premature release is observed under acidic and neutral conditions, making them ideal for use as a new class of colon-specific oral delivery systems. Importantly, these systems provide very promising possibilities for many medical applications that require an increase or decrease in the rate of drug release, depending on disease evolution. Upon incorporation into mesoporous silica materials, the antitumour activity of Ti3SiW9 against Ls-174-T was improved from 0.8 mg mL−1 to 0.186 and 0.102 mg mL−1 for Ti3SiW9@MMSN-NH2 and Ti3SiW9@BMSM-NH2, respectively.
Co-reporter:Ling Yuan, Chao Qin, Xinlong Wang, Yangguang Li and Enbo Wang
Dalton Transactions 2009 (Issue 21) pp:4169-4175
Publication Date(Web):22 Apr 2009
DOI:10.1039/B818535B
A series of novel organic–inorganic assemblies, {Ag3(2,2′-bipy)2(4,4′-bipy)2}{Ag(2,2′-bipy)2}{Ag(2,2′-bipy)}[AlW12O40]·H2O (1), [Ag(phen)2]3[Ag(phen)3][AlW12O40]·H5O2 (2) and {Co(2,2′-bipy)3}3{Co(H2O)(2,2′-bipy)2[AlW12O40]}2·H2O (3) (2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine, phen = 1,10-phenanthroline) constructed from Keggin-type [AlW12O40]5− polyoxoanion and transition-metal organoamine subunits, have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TGA), electrochemical properties and single-crystal X-ray diffraction. A remarkable aspect of compound 1 is that there exists four types of coordination configurations for the five crystallographically independent Ag centers, and this phenomenon has never been observed in polyoxometalate (POM) chemistry. The trimeric {[Ag(phen)2]3}3+ cluster in compound 2 is firstly extended into an interesting one-dimensional wave-like array and then is further extended into a three-dimensional supramolecular network with the [AlW12O40]5−clusters residing in the interstices of this three-dimensional framework. The most striking structure feature of compound 3 is that three water molecules linearly arrange between the adjacent monosupporting {Co(H2O)(2,2′-bipy)2[AlW12O40]}3− anions, leading to the formation of the three-dimensional supramolecular network by weak interactions.
Co-reporter:Yanfei Qi, Enbo Wang, Juan Li, Yangguang Li
Journal of Solid State Chemistry 2009 Volume 182(Issue 10) pp:2640-2645
Publication Date(Web):October 2009
DOI:10.1016/j.jssc.2009.07.022
Two new composite solids, [Ag(btx)]4H2V10O28·2H2O 1 and [Ag(biim)]2V4O112 (btx=1,4-bis(triazol-1-ylmethyl)benzene, biim=1,1′-(1,4-butanediyl)bis(imidazole)), have been synthesized and characterized by elemental analysis, IR, TGA and single-crystal X-ray diffraction. Compound 1 contains two one-dimensional (1D) polymeric chains, {Ag2(btx)2}2+ and [Ag2(btx)2H2V10O28]2−, that are assembled by supramolecular forces into an intriguing two-dimensional (2D) poly(pseudo-rotaxane) network. Compound 2 comprises cationic {Ag2(biim)2}2+ three-dimensional (3D) framework penetrated by anionic [V4O11]n2n- chains. The electrochemical properties of the two compounds have been studied.Two new examples of Ag/organonitrogen/polyoxovanadate composite solids with rare poly(pseudo-rotaxane) architectures have been synthesized and characterized.
Co-reporter:Rui Xu, Jiawei Wang, Qiuyu Li, Guoying Sun, Enbo Wang, Siheng Li, Jianmin Gu, Mingliang Ju
Journal of Solid State Chemistry 2009 Volume 182(Issue 11) pp:3177-3182
Publication Date(Web):November 2009
DOI:10.1016/j.jssc.2009.08.033
We developed a facile synthetic route of porous cobalt oxide (Co3O4) nanorods via a microemulsion-based method in combination with subsequent calcination process. The porous structure was formed by controlled decomposition of the microemulsion-synthesized precursor CoC2O4 nanorods without destruction of the original morphology. The as-prepared Co3O4 nanorods, consisting of small nanoparticles with diameter of 80–150 nm, had an average diameter of 200 nm and a length of 3–5 μm. The morphology and structure of synthesized samples were characterized by transmission electron microscopy and scanning electron microscopy. The phase and composition were investigated by X-ray powder diffraction and X-ray photoelectron spectroscopy. The optical property of Co3O4 nanorods was investigated. Moreover, the porous Co3O4 nanorods exhibited high electrochemical performance when applied as cathode materials for lithium-ion batteries, which gives them good potential applications.The porous Co3O4 nanorods synthesized via a microemulsion-based method in combination with subsequent calcination were applied in the negative electrode materials for lithium-ion batteries and exhibited high electrochemical performance.
Co-reporter:Qiuyu Li, Enbo Wang, Siheng Li, Chunlei Wang, Chungui Tian, Guoying Sun, Jianmin Gu, Rui Xu
Journal of Solid State Chemistry 2009 Volume 182(Issue 5) pp:1149-1155
Publication Date(Web):May 2009
DOI:10.1016/j.jssc.2008.10.039
ZnO hollow spheres with diameters ranging from 400 to 600 nm and the thickness of shell approximate 80 nm were synthesized by a simple polyoxometalate-assisted solvothermal route without using any templates. The effect of polyoxometalate concentration, reaction time and temperature on the formation of the hollow spheres was investigated. The results indicated that the hollow spheres were composed of porous shells with nanoparticles and polyoxometalate play a key role in controlling morphology of ZnO. A possible growth mechanism based on polyoxometalate-assisted assembly and slow Ostwald ripening dissolution in ethanol solution is tentatively proposed. In addition, the room temperature photoluminescence spectrum showed that the ZnO hollow spheres exhibit exciting emission features with wide band covering nearly all the visible region.ZnO hollow spheres with porous shell were synthesized by a one-step polyoxometalate-assisted solvothermal route at low temperature. Room temperature photoluminescence spectrum of the ZnO hollow spheres exhibits exciting emission features with a broad band covering nearly all the visible region.
Co-reporter:Jianmin Gu, Siheng Li, Enbo Wang, Qiuyu Li, Guoying Sun, Rui Xu, Hong Zhang
Journal of Solid State Chemistry 2009 Volume 182(Issue 5) pp:1265-1272
Publication Date(Web):May 2009
DOI:10.1016/j.jssc.2009.01.041
A dual iron precursors system in a hydrothermal process was developed for controllable fabrication of α-Fe2O3 hierarchical structures with different morphologies. Micro-pines, snowflakes and bundles were successfully synthesized simply by tuning the total concentration of the two iron precursors K4[Fe(CN)6] and K3[Fe(CN)6] and their molar ratio. The obtained α-Fe2O3 hierarchical structures were characterized using field-emission scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy and energy-dispersive X-ray analysis. The effect of experimental conditions on the morphologies of the α-Fe2O3 crystals was systematically investigated. A possible formation mechanism of different α-Fe2O3 hierarchical structures was proposed. Good photocatalytic properties were observed for all the hierarchical structures.A dual iron precursors system in a hydrothermal process was developed for controllable fabrication of various α-Fe2O3 hierarchical structures. Micro-pines, snowflakes and bundles were successfully fabricated by simply tuning the total concentration of the two iron precursors and their molar ratio. A possible formation mechanism of these structures was proposed.
Co-reporter:Feng Fu, Dong-Sheng Li, Xiao-Gang Yang, Cui-Qiao Zhang, Ya-Pan Wu, Jun Zhao, En-Bo Wang
Inorganic Chemistry Communications 2009 Volume 12(Issue 7) pp:657-659
Publication Date(Web):July 2009
DOI:10.1016/j.inoche.2009.05.015
Circular and rhombic tubular building blocks interweave mutually into a novel 2-fold interpenetrated 3D PtS framework [Zn(ADB)(H2O)]n (1) (H2ADB = azobenzen-4,4′-dicarboxylic acid), with hydrogen-bonded–O–metal–O–chain. In additional, solid-state properties such as photoluminescence and thermal stability of the complex 1 have also been studied.A novel coordination polymer [Zn(ADB)(H2O)]n has been successfully synthesized through hydrothermal route, which shows 2-fold interpenetrated 3D PtS framework as well as hydrogen-bonded –O–metal–O–chain and intense photoluminescence.
Co-reporter:Shuang Yao, Zhiming Zhang, Yangguang Li, Enbo Wang
Inorganic Chemistry Communications 2009 Volume 12(Issue 10) pp:937-940
Publication Date(Web):October 2009
DOI:10.1016/j.inoche.2009.05.024
A hexagonal {Cu6} cluster-containing tungstoantimonite, [Cu(enMe)2(H2O)]2{Cu(enMe)2[Cu(enMe)]3[Cu(H2O)]3(SbW9O33)2}·5H2O (1, enMe = 1,2-diaminopropane) has been successfully synthesized under hydrothermal conditions. The {Cu6} cluster in 1 is stabilized by both the inorganic O-donor ligand {B-α-SbW9O33}9− and the organic N-donor ligand enMe, leading to a hybrid inorganic-metal-organic sandwich-type polyoxometalate. The sandwich-type polyoxoanions are further connected into a 3D supramolecular framework via hydrogen bonding interactions between 1,2-enMe molecules and the sandwich-type polyoxoanions. The magnetic study indicates that intramolecular ferromagnetic Cu–Cu interactions exist in the hexanuclear metal-cluster.A 3D supramolecular architecture constructed from the {Cu6}-containing sandwich-type tungstoantimonite has been successfully synthesized under hydrothermal conditions, in which the {Cu6} cluster was stabilized by both the inorganic O-donor polyoxometalate ligands and the organic N-donor ligands.
Co-reporter:Wei-Lin Chen, Bao-Wang Chen, Yang-Guang Li, Yong-Hui Wang, En-Bo Wang
Inorganica Chimica Acta 2009 Volume 362(Issue 14) pp:5043-5054
Publication Date(Web):10 November 2009
DOI:10.1016/j.ica.2009.08.014
Co-reporter:Song Chang, Yan-Fei Qi, En-Bo Wang, Zhiming Zhang
Inorganica Chimica Acta 2009 Volume 362(Issue 2) pp:453-457
Publication Date(Web):20 January 2009
DOI:10.1016/j.ica.2008.04.048
Two novel Zn6 sandwiched polyoxometalates, [Zn(phen)2]2[Zn6(phen)2(AsW9O33)2] (1) and K11H2Zn[(ZnCl)6(AsW9O33)2]Cl · 27H2O (2), have been synthesized and characterized by X-ray single-crystal analysis, IR, and fluorescence spectrum. The polyoxoanions in both compounds can be characterized as two {AsIIIW9O33}9− moieties linked through Zn6 transition-metal cluster to form the sandwich-type polyoxotungstates. In compound 1, six Zn atoms in the equatorial part of the polyoxoanions have two different coordination environments: four Zn sites exhibit distorted octahedral geometry, and the other two Zn atoms show square pyramidal geometry. In the polyoxoanion of compound 2, all Zn atoms are square pyramidal geometry, and held together to form a hexagonal metallocycle by edge-sharing oxygen atoms. In this Zn6 cluster, the shortest distance of neighboring Zn⋯Zn is 3.147(1) Å. In addition, compound 2 exhibits purple photoluminescence at room temperature.Two novel Zn6 sandwiched polyoxometalates, [Zn(phen)2]2[Zn6(phen)2(AsW9O33)2] (1) and K11H2Zn [(ZnCl)6(AsW9O33)2]Cl · 27H2O (2), have been synthesized. Both of the polyoxoanions can be viewed as two [AsIIIW9O33]9− moieties linked by Zn6 transition-metal cluster.
Co-reporter:Huaqiao Tan, Weilin Chen, Yang-Guang Li, Ding Liu, Limin Chen, Enbo Wang
Journal of Solid State Chemistry 2009 Volume 182(Issue 3) pp:465-470
Publication Date(Web):March 2009
DOI:10.1016/j.jssc.2008.11.011
In this paper, three pure inorganic eight-connected self-catenated networks based on the Silverton-type polyoxometalate [CeMo12O42]8− with lanthanide, transition metal and alkali metal cations as linkers: [Li(H2O)4]2Co(H2O)4Ce(H2O)3[CeMo12O42]·3H2O (1), H0.5[Li(H2O)4]2.5[Ni(H2O)4]0.5Ce(H2O)3[CeMo12O42]·3H2O (2) and H[Li(H2O)4]3Ce(H2O)3[CeMo12O42]·3H2O (3) have been successfully synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectroscopy, electrochemical analyses and single crystal X-ray diffraction. The single crystal X-ray diffraction analyses reveal that compounds 1–3 are isostructural. The [CeIVMo12O42]8− polyoxoanions are connected by Ce4+ to form the infinite 1D chains. And then the parallel stacking chains linked by transition metal cations and lithium ions construct to an eight-connected self-catenated 424563 topology framework.Three extended frameworks based on Silverton-type polyoxometalate have been successfully synthesized. In these compounds, [CeIVMo12O42]8− clusters are connected by lanthanide, transition metal and Li+ to form a 424563 network.
Co-reporter:Jing-Xin Meng;Xiao-Lan Wang;Hai Fu;Yan Zhong
Transition Metal Chemistry 2009 Volume 34( Issue 3) pp:361-366
Publication Date(Web):2009 April
DOI:10.1007/s11243-009-9204-1
Three new organic–inorganic hybrid compounds H[CuI(dafo)2]3{[CuI(dafo)2]2P2W18O62} · H2O (1), [CuI(dafo)2]3PMo12O40 (2) and [CuI(dafo)2]4SiW12O40 (3) (dafo = 4, 5-diazafluoren-9-one) have been hydrothermally synthesized and characterized by IR, TG and CV. Compound 1 exhibits a 3D supramolecular framework based on weak interactions between bisupported Dawson structure P2W18O626− units and copper-complex fragments. With the aid of π–π stacking and hydrogen bonding interactions, a 1D supramolecular framework accommodating polyoxometalate (POM) anions is generated in 2. Compound 3 has similar fundamental units as 2, but the units are assembled in a different way. The distinction of their structures indicates that the POMs are the key factor in determining the frameworks of the final products. The electrochemical properties of these compounds have been studied using bulk-modified carbon paste electrodes.
Co-reporter:Huaqiao Tan;Yangguang Li ;Weilin Chen;Ding Liu;Zhongmin Su ;Ying Lu Dr.;Enbo Wang
Chemistry - A European Journal 2009 Volume 15( Issue 41) pp:10940-10947
Publication Date(Web):
DOI:10.1002/chem.200901112
Abstract
Five compounds based on [MnMo9O32]6−: (Himi)6[MnMo9O32] (1) (imi=imidazole), Na2(Himi)4[MnMo9O32]⋅2 H2O (2), Na3(Himi)3[MnMo9O32] (3), D-NH4Mn2.5[MnMo9O32]⋅11 H2O (4 a), and L-NH4Mn2.5[MnMo9O32]⋅11 H2O (4 b) were prepared and characterized. X-ray crystallographic analysis revealed that compounds 1 and 2 with imidazole molecules as linkers are racemic compounds; compound 3 is a racemic solid solution of Na+ cations and the polyoxoanion [MnMo9O32]6−; and compounds 4 a and 4 b are enantiomers. In compound 4, the homochiral polyoxoanions [MnMo9O32]6− are connected by Mn2+ cations to form a unique (45⋅6)(47⋅68) topology net framework. By adjusting the linkers from imidazole molecules to Na+ and finally Mn2+ cations, the chiral polyoxoanions [MnMo9O32]6− were changed from a racemic compound to a conglomerate. This means that spontaneous resolution can be efficiently realized by connecting homochiral polyoxoanions into one-dimensional (1D), 2D, and 3D structures, with an emphasis on using appropriate linkers with substantial interaction strength, directionality, and enantioselectivity.
Co-reporter:Y. L. Si;C. G. Liu;E. B. Wang;Z. M. Su
Theoretical Chemistry Accounts 2009 Volume 122( Issue 3-4) pp:217-226
Publication Date(Web):2009 March
DOI:10.1007/s00214-008-0501-0
To probe the cooperativity of charge transfer between organoimido and hexamolybdate, and enhance the second-order nonlinear optical (NLO) response of organoimido derivatives of hexamolybdates, electronic structures and second-order NLO properties of a series of charge-transfer covalently bonded organoimido derived hexamolybdate complexes with donor-(π conjugated bridge)-acceptor-(π conjugated bridge)-donor or acceptor-(π conjugated bridge)-donor-(π conjugated bridge)-acceptor structures were studied by density functional theory. Studies show that different combinations of the donor, acceptor, heterocycle, –C≡C– and –N=N– moieties, and orientation of heterocycle remarkably affect the second-order NLO responses. The complexes containing electronic acceptor matched with the direction of charge transfer possess remarkable large molecular second-order polarizabilities. Electronic transitions to crucial excited states show that x-polarized transition, contributed to the off-diagonal second-order polarizabiliy tensor (βzxx), possesses lower excited energy compared with z-polarized transition which accounted for the diagonal second-order polarizabiliy tensor (βzzz) and thus led to the large in-plane nonlinear anisotropy (u = βzxx/βzzz) value, as well as good two-dimensional (2-D) second-order NLO properties. These complexes can be used as excellent 2-D second-order NLO materials from the standpoint of both large β and u values.
Co-reporter:Weilin Chen, Yangguang Li, Yonghui Wang, Enbo Wang and Zhiming Zhang
Dalton Transactions 2008 (Issue 7) pp:865-867
Publication Date(Web):04 Dec 2007
DOI:10.1039/B717419E
A new polytungstoarsenate-based 3d–4f heterometallic aggregate has been synthesized, consisting of three {α-AsW10O38} fragments bridged by three {Fe–(µ3-O)3–Ce} heterometallic clusters.
Co-reporter:Zhiming Zhang, Jia Liu, Enbo Wang, Chao Qin, Yangguang Li, Yanfei Qi and Xinlong Wang
Dalton Transactions 2008 (Issue 4) pp:463-468
Publication Date(Web):06 Nov 2007
DOI:10.1039/B712903C
Two new compounds constructed from tetra-Ni-substituted sandwich-type polyoxometalates functionalized by organic groups, (NH4)2[Ni4(enMe)8(H2O)2Ni4(enMe)2(PW9O34)2]·9H2O (enMe = 1,2-diaminopropane) (1) and Na2[H6N2(CH2)6]2{Ni4[H4N2(CH2)6]2(H2PW9O34)2}·7H2O (2), have been successfully synthesized under hydrothermal conditions. Single-crystal X-ray diffraction analysis is carried out on these two compounds (1 and 2), which both crystallize in the triclinic system. Compound 1 represents the first example of a 2D layer structure consisting of the sandwich-type polyoxoanions with six supporting [Ni(enMe)2]2+ moities and two organic functionalized groups. Compound 2 exhibits a 1D chain-like structure based on sandwich-type polyoxoanions and sodium cations, which are further connected into a 2D layer structure viahydrogen-bonding interactions between the 1,6-hexanediamine molecules and the sandwich-type [Ni4(H4N2(CH2)6)2(H2PW9O34)2]6– polyoxoanions. A magnetic study of the two compounds indicates that intramolecular ferromagnetic Ni–Ni interactions exist in the tetranuclear metal cluster.
Co-reporter:Yanfei Qi, Yangguang Li, Enbo Wang, Zhiming Zhang and Song Chang
Dalton Transactions 2008 (Issue 17) pp:2335-2345
Publication Date(Web):19 Mar 2008
DOI:10.1039/B713115A
Five new organic–inorganic assemblies, [Co(en)3][Co(en)2As8V14O42(H2O)]·16H2O (1), [Ni(Meen)3]4[Ni(Meen)2][As8V14O42(NO3)]2·8H2O (2), [Cd(en)3][Cd(phen)(en)(H2O)2][(en)CdAs8V13O41(H2O)]·1.5H2O (3), [Cd(phen)2(en)]2[(phen)CdAs8V13O41(H2O)]·21H2O·phen (4), [Zn(en)2]2[(bpe)2Zn2As8V12O40(H2O)] (5) (en = ethylenediamine, Meen = 1,2-diaminopropane, phen = 1,10-phenanthroline, and bpe= 1,2-bis(4-pyridyl)ethylene) have been synthesized and characterized. Among them, compounds 1 and 2 are constructed from the [As8V14O42] cluster; compounds 3 and 4 are constructed from the Cd-substituted polyoxovanadate [CdAs8V13O41] cluster, while compound 5 consists of bizinic-substituted polyoxovanadate [Zn2As8V12O40] building units. It can be assumed that the metal ions used in these reaction systems play a crucial role in controlling the formation of the arsenic–vanadium–cluster backbones, and further leading to the formation of hybrids based on these clusters.
Co-reporter:Qiuyu Li, Zhenhui Kang, Baodong Mao, Enbo Wang, Chunlei Wang, Chungui Tian, Siheng Li
Materials Letters 2008 Volume 62(Issue 16) pp:2531-2534
Publication Date(Web):15 June 2008
DOI:10.1016/j.matlet.2007.12.041
With the assistance of Keggin-type polyoxometalate (POM) H3PW12O40·nH2O (PW12), ZnO microspheres have successfully been synthesized by a direct route, using zinc acetate dihydrate solid and dilute PW12 absolute ethanol solution at 120 °C for 24 h. The effects of PW12 concentration and reaction time were investigated. The results showed that PW12 played a vital role for the formation of the ZnO microspheres during the solvothermal treatment and the original framework of PW12 was not destroyed after the solvothermal treatment. Finally, the room temperature photoluminescence (PL) spectrum of the ZnO microspheres exhibited a sharp and strong ultraviolet (UV) emission at 390 nm and a quite weak visible emission at around 520 nm, respectively.
Co-reporter:Song Chang, Yang-Guang Li, En-Bo Wang, Lin Xu, Chao Qin, Xin-Long Wang, Hua Jin
Journal of Molecular Structure 2008 Volume 875(1–3) pp:462-467
Publication Date(Web):17 March 2008
DOI:10.1016/j.molstruc.2007.05.027
The self-assembly of [As2W19O67(H2O)]14− precursors in acidic aqueous solution with different pH value led to the isolation of a new highly-nuclear polytungstoarsenate aggregates, [{(W4O9)(H2O)2}{As2W19O67(H2O)}2]22−1. It can be characterized as two [As2W19O67(H2O)]14− units hinged together by a {(W4O9)(H2O)2} fragment. Polyoxoanion 1 is the second largest polytungstoarsenate cluster composed of new {As2W21} building blocks. Crystal data for 1: triclinic, space group C2, a = 26.274(5) Å, b = 24.321(5) Å, c = 18.764(4) Å, β = 128.58(3)°, V = 9373(3) Å3, Z = 2.
Co-reporter:Ling Yuan, Chao Qin, Xinlong Wang, Enbo Wang, Yangguang Li
Solid State Sciences 2008 Volume 10(Issue 8) pp:967-975
Publication Date(Web):August 2008
DOI:10.1016/j.solidstatesciences.2007.12.011
Three new extended frameworks based on the paradodecatungstate cluster and transition metals or alkaline-earth metal have been synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TGA), X-ray powder diffraction (XRPD) and single crystal X-ray diffraction. The 2D layered structure of the compound [Na8(H2O)28][Mn(H2O)2(H2W12O42)]·4H2O (1) is formed by the interconnection of 1D [Mn(H2O)2(H2W12O42)]n8− and [Na8(H2O)28]n8+ chains. In the compound [Zn5(H2O)20(H2W12O42)]·16H2O (2), two neighboring paratungstate ions [H2W12O42)]10− are linked by [Zn4(H2O)14]8+ units, leading to the formation of a 2D layer containing rhombic channels. The anion [Sr2(H2O)6(H2W12O42)]6− of the compound K[Na5(H2O)6][Sr2(H2O)6(H2W12O42)]·18H2O (3) shows a layer-like structure in which paratungstate-B units act as six-dentate ligands coordinating to six Sr2+ ions through the terminal oxygen atoms. Interestingly, the strong involvement of the potassium and sodium counteractions leads the neighboring layers to tie together generating a 3D network containing two types of channels. Furthermore, compounds 1–3 give intense blue luminescent emissions in solid state and the magnetic susceptibility of compound 1 has also been studied.Three new polyoxometalate compounds based on the paradodecatungstate cluster and transition metals or alkaline-earth metal, [Na8(H2O)28][Mn(H2O)2(H2W12O42)]·4H2O (1), [Zn5(H2O)20(H2W12O42)]·16H2O (2), and K[Na5(H2O)6][Sr2(H2O)6(H2W12O42)]·18H2O (3) have been synthesized and characterized, in which paradodecatungstate clusters serve as two-, eight-, and six-dentate ligands, respectively, linking secondary metal ions into high-dimensional frameworks containing channels. This work provides new possibilities for the design of high-dimensional covalent solid materials.
Co-reporter:Zhen-He Xu, Jia Liu, En-Bo Wang, Chao Qin, Qiong Wu, Quan Shi
Journal of Molecular Structure 2008 Volume 873(1–3) pp:41-45
Publication Date(Web):17 February 2008
DOI:10.1016/j.molstruc.2007.03.004
The new tungstobismutate K2Na6(NH4)6[(VO)2(BiW9O33)2] · 41H2O (1) anion has been obtained by reaction of Na2WO4 · 2H2O, Bi2(SO4)3, and VOSO4 · 5H2O in NaAc buffer under moderate condition, and characterized by IR, UV, element analysis, TG and single-crystal X-ray analysis. Polyoxoanion 1 was composed of two [BiW9O33]9− units linked by two vavadium ions. Compound 1 represents the first dimeric species sandwiching two vanadium metal ions between two lacunary Keggin anions. The crystal data for two compounds are the following: 1, triclinic, space group P−1, a = 12.852(3) Å, b = 16.275(3) Å, c = 24.646(5) Å, α = 70.80(3)°, β = 86.88(3)°, γ = 83.48(3)°, V = 4836.0(17) Å, Z = 2.
Co-reporter:Zhiming Zhang, Enbo Wang, Yangguang Li, Haiyan An, Yanfei Qi, Lin Xu
Journal of Molecular Structure 2008 Volume 872(2–3) pp:176-181
Publication Date(Web):29 January 2008
DOI:10.1016/j.molstruc.2007.02.033
Two new polyoxotungstates K4Na4[Co2(H2O)10Co4(H2O)2(B-α-GeW9O34)2] · 28.5H2O (1) and K2Na6[Co2(H2O)10Co4(H2O)2(B-α-SiW9O34)2] · 17H2O (2) have been obtained in aqueous solution and characterized by IR, TG, element analysis, magnetism, electrochemistry and single-crystal X-ray analysis. The polyoxoanion frameworks of the two compounds consist of the sandwich-type polyoxoanion [Co4(H2O)2(B-α-XW9O34)2]8− (X = Ge and Si) covalently linked with two Co2+ cations by two μ2-O atoms. The magnetic properties of compound 1 have been studied by measuring its magnetic susceptibility in the temperature range 2.0–300.0 K, indicating the existence of intramolecular ferromagnetic Co–Co interactions. The electrochemical properties of the two compounds were detected in pH 3 buffer solutions, and three redox couples were detected in the multi-cobalt-substituted POMs.
Co-reporter:Zhiming Zhang, Yanfei Qi, Enbo Wang, Yangguang Li, Huaqiao Tan
Inorganica Chimica Acta 2008 Volume 361(Issue 7) pp:1797-1804
Publication Date(Web):20 May 2008
DOI:10.1016/j.ica.2007.09.014
Two new multi-cobalt-containing polyoxotungstates K4Na6Co2(H2O)12{Co(H2O)4[Co2(H2O)10Co4(H2O)2(B-α-SiW9O34)2]2} · 40H2O (1) and K10Na2[Co4(H2O)2(GeW9O34)2] · 20H2O (2) have been obtained by the routine synthetic reactions in aqueous solution. The polyoxoanion framework of 1 consists of two sandwich-type polyoxoanions [Co4(H2O)2(B-α-SiW9O34)2]12− connected together by a [CoO2(H2O)4] cluster to constitute the sandwich dimer, and then, four isolated Co(H2O)5 cations coordinate to the dimer through four μ2-O atoms. The polyoxoanion 2 is isomorphic to the sandwich-type polyoxoanion [Co4(H2O)2(B-α-SiW9O34)2]12− in 1. The magnetic property of compound 1 has been studied by measuring its magnetic susceptibility in the temperature range 2.0–300.0 K, indicating the existence of intramolecular ferromagnetic Co–Co interactions, and, the electrochemical properties of 1 and 2 are detected in the pH 4 buffer solution.A new polyoxotungstate K4Na6Co2(H2O)12{Co(H2O)4[Co2(H2O)10Co4(H2O)2(SiW9O34)2]2} · 40H2O (1) has been obtained in an aqueous solution system. The polyoxoanion framework of 1 consists of two sandwich-type polyoxoanions [Co4(H2O)2(B-α-SiW9O34)2] connected together by a [CoO2(H2O)4] cluster to constitute the sandwich dimer which is covalently linked together with another four isolated Co2+ cations by four μ2-O atoms.
Co-reporter:Siheng Li, Enbo Wang, Chungui Tian, Baodong Mao, Zhenhui Kang, Qiuyu Li, Guoying Sun
Journal of Solid State Chemistry 2008 Volume 181(Issue 7) pp:1650-1658
Publication Date(Web):July 2008
DOI:10.1016/j.jssc.2008.05.021
In this paper, a simple strategy is developed for rational fabrication of a class of jingle-bell-shaped hollow structured nanomaterials marked as Ag@MFe2O4 (M=Ni, Co, Mg, Zn), consisting of ferrite hollow shells and metal nanoparticle cores, using highly uniform colloidal Ag@C microspheres as template. The final composites were obtained by direct adsorption of metal cations Fe3+ and M2+ on the surface of the Ag@C spheres followed by calcination process to remove the middle carbon shell and transform the metal ions into pure phase ferrites. The as-prepared composites were characterized by X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis spectroscopy and SQUID magnetometer. The results showed that the composites possess the magnetic property of the ferrite shell and the optical together with antibacterial property of the Ag core.MFe2O4 (M=Ni, Co, Mg, Zn) hollow spheres with a noble metal nanoparticle core were successfully prepared by using colloidal metal@C core–shell spheres as templates with no need of surface modification. The shell thickness and magnetic properties of the ferrite hollow spheres could be controlled by varying the synthetic parameters.
Co-reporter:Chunlei Wang, Qiuyu Li, Baodong Mao, Enbo Wang, Chungui Tian
Materials Letters 2008 Volume 62(8–9) pp:1339-1341
Publication Date(Web):31 March 2008
DOI:10.1016/j.matlet.2007.08.044
A new reaction was developed to synthesize ZnO nanoparticles with nearly uniform, spherical morphology ranging from 25 to 50 nm via directly oxidizing zinc powders with iodine in ethanol. Iodine plays key roles in the nucleation of ZnO nanoparticles and it is favorable for the growth of ZnO nanoparticles gradually and avoids the agglomeration to some extent. Moreover, this process is well repeatable and easy controlled. The morphology evolution of the ZnO nanoparticles at different reaction time was monitored through transmission electron microscope (TEM). The room temperature photoluminescence (PL) spectrum displays strong ultraviolet emission peaks and relative weak near band-edge free excitonic emission peak.
Co-reporter:Zhiming Zhang;Shuang Yao;Enbo Wang;Quan Shi;Hong Zhang
Journal of Cluster Science 2008 Volume 19( Issue 3) pp:521-530
Publication Date(Web):2008 September
DOI:10.1007/s10876-008-0194-5
Two new tungstogermanates K2Na10[Cu4(GeW9O34)2] · 15.5H2O (1) and K4Na6[Cu3.5W0.5(H2O)2(GeW9O34)2] · 17H2O (2) have been obtained by the conventional aqueous solution methods and characterized by IR, element analysis, electrochemistry and single-crystal X-ray analysis. Compound 1 is composed of the [Cu4(GeW9O34)2]12− anions linked by two equivalent bonds of Cu–O–W, representing the first one-dimensional chain-like structure based on sandwich-type polyoxometalates by direct condensation to form oxo-bridged arrays of clusters. Compound 2 is a sandwich structure, consisting of two trivacant [GeW9O34]10− units linked by a [Cu3.5W0.5(H2O)2] cluster, and the anions are linked by the K+ and Na+ to form a three-dimensional structure.
Co-reporter:Hongli Chen;Yan Ding;Enbo Wang;Xinxin Xu;Yanfei Qi
Transition Metal Chemistry 2008 Volume 33( Issue 3) pp:341-346
Publication Date(Web):2008 April
DOI:10.1007/s11243-007-9047-6
In this article, two compounds [H2bpy][Ln(DMF)4(H2O)3(Hbpy)][H2W12O40] (Ln = La,Ce; DMF = N,N-dimethylformamide, bpy = 4,4′-bipyridine) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectra, and TG analysis. X-Ray analysis showed that the [Ln(DMF)4(H2O)3(Hbpy)]4+ unit is supported on the α-Keggin polyoxoanion [H2W12O40]6− via the surface bridging oxygen atom. The [H2bpy][Ln(DMF)4(H2O)3(Hbpy)][H2W12O40] entity is further extended into 2D supramolecular networks with 1-D channels by hydrogen-bonding interactions, in which 4,4′-bipy ligands reside. To the best of our knowledge, these complexes represent the first examples of rare earth metal-organic complex-decorated α-metatungstate clusters. Furthermore, the electrochemical properties of these compounds have been studied via the method of bulk-modified carbon paste electrodes.
Co-reporter:Xinxin Xu, Ying Ma, Enbo Wang
Journal of Solid State Chemistry 2007 Volume 180(Issue 11) pp:3136-3145
Publication Date(Web):November 2007
DOI:10.1016/j.jssc.2007.05.033
In this article, seven coordination polymers: [Cd(C5H6O4)(C10H8N2)]n (1), [Zn(C5H6O4)(C10H8N2)]n (2), [Cd(C6H8O4)(C10H8N2)]n (3), {[Mn(C10H8N2)(H2O)4] (C4H4O4)·4H2O}n (4), [Mn5(C4H4O4)4(O)]n (5), [Cd(C4H4O4)(C10H8N2)(H2O)]n (6) and [Zn(C6H6O4)(C12H8N2)(H2O)]n (7) were synthesized and characterized by single-crystallographic X-ray diffraction. Compounds 1 and 2 are two-dimensional layers connected by glutarate anions and 4,4′-bpy. Unlike compounds 1 and 2, compound 3 is a two-fold interpenetration network. Compound 4 is a one-dimensional chain-like structure, which is further extended to two-dimensional supramolecular layer structure with hydrogen bond. During the synthesis of compound 4, to our surprise, we got compound 5; compound 5 is an interesting three-dimensional network composed of pentanuclear Mn(II) building units and succinate anions. Compound 6 is also a two-dimensional supramolecular layer structure composed of one-dimensional chain-like structure with hydrogen bonds and Π–Π interactions. Compound 7 is also a one-dimensional chain-like structure, which is further connected with the same kind of interaction to generate two-dimensional supramolecular layer structure. Furthermore, compounds 1 and 2 both exhibit fluorescent property at room temperature.Seven complexes composed by 3D metal ions, aliphatic acid ligand and rigid bidentate nitrogen ligands: 4,4′-bpy, 2,2′-bpy and 1,10′-phen. With the change of the carbon number of the backbone of aliphatic dicarboxylate ligand, we can synthesize different complexes with various structures.
Co-reporter:Zhiming Zhang, Enbo Wang, Yangguang Li, Yanfei Qi, Huaqiao Tan
Journal of Molecular Structure 2007 Volume 843(1–3) pp:128-131
Publication Date(Web):29 October 2007
DOI:10.1016/j.molstruc.2007.01.017
A new tungstogermanate NaK5Ni3(H2O)18[Ni4(H2O)2 (GeW9O34)2] ·13.5H2O (1) has been obtained in aqueous solution and characterized by IR, UV, element analysis, TG, electrochemistry and X-ray single crystal diffraction analysis. Polyoxoanion 1 was composed of two [GeW9O34]10− units linked by a Ni4 cluster, which was first observed, and the anions were connected by K+ ions to constitute a novel one-dimensional chainlike complex.
Co-reporter:Jianmin Gu, Siheng Li, Mingliang Ju, Enbo Wang
Journal of Crystal Growth (1 April 2011) Volume 320(Issue 1) pp:46-51
Publication Date(Web):1 April 2011
DOI:10.1016/j.jcrysgro.2011.01.072
In this paper, a series of MFe2O4 (M=Mg, Co, Ni, Zn) hollow spheres are successfully prepared by hydrothermal treatment of the mixed solution of glucose, Fe3+ and M2+ and a subsequent calcination process. After the calcination process, the carbon core of the hydrothermally prepared composite carbon spheres was removed and the metal components were transformed to pure phase ferrites. The final products (ferrite hollow spheres) were characterized using X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy and the magnetic properties were evaluated using a SQUID magnetometer.
Co-reporter:Xin-Bao Han ; Zhi-Ming Zhang ; Teng Zhang ; Yang-Guang Li ; Wenbin Lin ; Wansheng You ; Zhong-Min Su
Journal of the American Chemical Society () pp:
Publication Date(Web):March 24, 2014
DOI:10.1021/ja412886e
A series of all-inorganic, abundant-metal-based, high-nuclearity cobalt–phosphate (Co–Pi) molecular catalysts [{Co4(OH)3(PO4)}4(SiW9O34)4]32– (1), [{Co4(OH)3(PO4)}4(GeW9O34)4]32– (2), [{Co4(OH)3(PO4)}4(PW9O34)4]28– (3), and [{Co4(OH)3(PO4)}4(AsW9O34)4]28– (4) were synthesized and shown to be highly effective at photocatalytic water oxidation. The {Co16(PO4)4} cluster contains a Co4O4 cubane which is structurally analogous to the [Mn3CaO4] core of the oxygen-evolving complex (OEC) in photosystem II (PSII). Compounds 1–4 were shown to be the first POM-based Co–Pi-cluster molecular catalysts for visible light-driven water oxidation, thus serving as a functional model of the OEC in PSII. The systematic synthesis of four isostructural analogues allowed for investigating the influence of different heteroatoms in the POM ligands on the photocatalytic activities of these Co–Pi cluster WOCs. Further, the POM-based photocatalysts readily recrystallized from the photocatalytic reaction systems with the polyoxoanion structures unchanged, which together with the laser flash photolysis, dynamic light-scattering, 31P NMR, UV–vis absorption, POM extraction, and ICP-MS analysis results collectively confirmed that compounds 1–4 maintain their structural integrity under the photocatalytic conditions. This study provides not only a valuable molecular model of the “Co–Pi” catalysts with a well-defined structure but also an unprecedented opportunity to fine-tune high-nuclearity POM clusters for visible light-driven water splitting.
Co-reporter:Zhiming Zhang ; Yangguang Li ; Yonghui Wang ; Yanfei Qi ;Enbo Wang
Inorganic Chemistry () pp:
Publication Date(Web):August 5, 2008
DOI:10.1021/ic800479k
The reaction between K12[H2P2W12O48] and CuCl2 in a NaCl aqueous solution assisted with organoamines (1,2-ethylenediamine (en), 1,6-hexamethylene diamine (hn), or both) leads to the isolation of three compounds: K4Na10[α1-CuP2W17O60(OH)]2·∼58H2O (1), Na2[H2en][H2hn]0.5[Cu(en)2]4.5[α1-CuP2W17O60(OH)]2·∼43H2O (2), and Na3[H2hn]2.5[α1-P2W17O60Cu(OH)2]·∼14H2O (3). The polyoxoanion [α1-CuP2W17O60(OH)]214− in 1 and 2 exhibits a double-Dawson-type polyoxoanion that consists of two α1-type mono-Cu-substituted Wells—Dawson anions, which can be synthesized by both the conventional aqueous solution method and the hydrothermal technique. Furthermore, the double-Dawson-type polyoxoanions in 2 are linked by the [Cu(en)2]2+ bridges to form 2-D networks, which are further packed into a 3-D supramolecular porous framework via extensive hydrogen bonding interactions, exhibiting two types of tunnels (A and B). Compound 3 possesses a 3-D supramolecular framework with 1-D tunnels constructed from the α1-type mono-Cu-substituted Wells—Dawson anion. The magnetic studies of compounds 1 and 2 indicate that weak antiferromagnetic interactions exist in these two compounds.
Co-reporter:Hong-Mei Zhang ; Yang-Guang Li ; Ying Lu ; Rodolphe Clérac ; Zhi-Ming Zhang ; Qiong Wu ; Xiao-Jia Feng
Inorganic Chemistry () pp:
Publication Date(Web):October 30, 2009
DOI:10.1021/ic901552f
A new Ni12 cluster based on polyoxometalate ligands [Ni12(OH)9WO4(W7O26(OH))(PW9O34)3]25− (1) has been assembled in aqueous solution containing [PW9O34]9−, WO42−, and NiCl2·6H2O. The Ni12 core in 1 shows a unique three-petal flower-shaped structure composed of three Ni4 cubane units. Magnetic investigation indicates the presence of dominantly ferromagnetic interactions within the Ni12 core.
Co-reporter:Xiang-Wei Guo, Xiao-Hong Li, Zhu-Jun Liu, Wei-Lin Chen, Xiao-Tao Zheng, En-Bo Wang and Zhong-Min Su
Inorganic Chemistry Frontiers 2017 - vol. 4(Issue 7) pp:NaN1191-1191
Publication Date(Web):2017/05/08
DOI:10.1039/C7QI00160F
Photosensitizers play a crucial role in p-type dye-sensitized solar cells (p-DSSCs). In this study, we first introduced two Dawson-type transition metal-substituted polyoxometalate dyes to co-sensitize the NiO electrode and achieved an overall power conversion efficiency (PCE) of 0.0464%, which is the highest value reported for inorganic photosensitizers in p-DSSCs.
Co-reporter:Yi-Jing Wang, Wei-Lin Chen, Li Chen, Xiao-Tao Zheng, Sha-Sha Xu and En-Bo Wang
Inorganic Chemistry Frontiers 2017 - vol. 4(Issue 3) pp:NaN565-565
Publication Date(Web):2017/01/17
DOI:10.1039/C6QI00570E
Sandwich-type polyoxometalates K6Na2Ni2[Ni4(H2O)2(SiW9O34)2]·30H2O(Ni4), K6Na2Co2[Co4(H2O)2(SiW9O34)2]·30H2O(Co4) and K10[Ni(H2O)2(γ-SiW10O35)2]·13.25H2O(Ni1) were doped into TiO2 separately and applied as photoanodes for dye-sensitized solar cells (DSSCs) for the first time, enhancing the current intensity and photoelectric conversion efficiency of the cells. The TiO2 and POM@TiO2 used in this paper were synthesized by a modified sol–gel method. The Jsc of pure P25 is 15.84 mA cm−2, the Voc is 0.637 V, the FF is 0.564, and the η is 5.69%. The Jsc of the prepared TiO2 is 16.48 mA cm−2, the Voc is 0.68 V, the FF is 0.537 and the η is 6.01%, which is a higher efficiency than that of pure P25, therefore the POMs@TiO2 were directly used in photoanodes without being formed into composites with P25 in this paper. The Jsc of 0.8% Ni4@TiO2 is 18.79 mA cm−2, the Voc is 0.71 V, the FF is 0.595 and the η is 7.94%, which is 32.1% higher than that of the prepared TiO2 based DSSC. 0.8% Co4@TiO2 and 0.8% Ni1@TiO2 modified photoanodes obtained power conversion efficiencies of 6.22% and 6.17%. The electron lifetimes of the self-prepared TiO2 and 0.8% Ni4@TiO2 are 13.5 ms and 28 ms respectively, calculated from a bode plot. Among the three kinds of sandwich-type POMs mentioned in this paper, the 0.8% Ni4 modified photoanode in DSSCs exhibited the best performance in enhancing light harvesting and reducing electron recombination. The energy levels of Ni4 were also investigated.
Co-reporter:Yue Jia, Hua-Qiao Tan, Zhi-Ming Zhang and En-Bo Wang
Journal of Materials Chemistry A 2013 - vol. 1(Issue 23) pp:NaN3685-3685
Publication Date(Web):2013/04/11
DOI:10.1039/C3TC30179F
By ion metathesis reactions, the dimethyldioctadecylammonium (DODA+) was used as the surfactant to encapsulate organic–inorganic hybrid polyoxometalates (POMs) (NH4)6{Mo2VO4[(Mo2VIO6)NH3CH2CH2CH2C(O)(PO3)2]2}·10H2O (POM-1) and (NH4)8{Mo2VO4[(Mo2VIO6)CH3C(O)(PO3)2]2}·14H2O (POM-2), resulting in two surfactant-encapsulated clusters (SECs) with characteristic thermotropic liquid-crystalline behavior. The chemical composition of the obtained SECs was determined by IR spectra, elemental analysis, TG analysis and NMR spectra. Also, polarized optical microscopy, differential scanning calorimetry (DSC), variable temperature X-ray diffraction (VT-XRD) and TEM of the samples were also performed, which revealed that both SECs show thermotropic liquid crystal behavior.
Co-reporter:Ge Jin, Shi-Ming Wang, Wei-Lin Chen, Chao Qin, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2013 - vol. 1(Issue 23) pp:NaN6730-6730
Publication Date(Web):2013/04/26
DOI:10.1039/C3TA10814G
A spherical keplerate {W72V30} acts as the electron acceptor in a photovoltaic system for the first time. It is a promising alternative electron acceptor to the traditional electron acceptor fullerene (C60). A water-soluble PPV derivative (P2) was chosen as the electron donor. This work represents a promising strategy in designing polymer photovoltaic devices.
Co-reporter:Jian-Sheng Li, Xiao-Jing Sang, Wei-Lin Chen, Lan-Cui Zhang, Zai-Ming Zhu, Yang-Guang Li, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 28) pp:NaN14577-14577
Publication Date(Web):2015/06/12
DOI:10.1039/C5TA03259H
A strategy was developed for the first time to fabricate highly dispersed and small-sized polyoxometalate nanoparticles loaded on a TiO2 film by using MIL-101 to prevent agglomeration, and calcination to break the metal–organic framework, which can result in performance improvement of quantum dot solar cells.
Co-reporter:Hongfei Shi, Huaqiao Tan, Wan-bin Zhu, Zaicheng Sun, Yuejia Ma and Enbo Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 12) pp:NaN6591-6591
Publication Date(Web):2015/02/18
DOI:10.1039/C4TA06736C
A series of Cr-doped Bi4Ti3O12/Bi2Ti2O7 (BTO) heterostructure fibers have been synthesized via a one-step, facile and economical electrospinning/calcination process. SEM and TEM results reveal that the diameters of the as-prepared fibers are 100 ± 30 nm. The light adsorption of Bi4Ti3O12 and Bi2Ti2O7 in the fibers has been remarkably improved by Cr doping. With increased Cr doping, XRD and XPS show that the amount of Bi2Ti2O7 increases in the fibers. As a result, the Bi4Ti3O12/Bi2Ti2O7 heterojunction structure is enhanced, which further promotes the charge separation of photogenerated charge carriers. Photocatalytic tests indicated that the as-prepared Cr-doped Bi4Ti3O12/Bi2Ti2O7 fibers exhibit good photocatalytic activity for photodegradation of methyl orange (MO) under visible-light irradiation.
Co-reporter:Li Chen, Weilin Chen, Huaqiao Tan, Jiansheng Li, Xiaojing Sang and Enbo Wang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 11) pp:NaN4133-4133
Publication Date(Web):2016/02/10
DOI:10.1039/C5TA10260J
Quantum dot sensitized solar cells with high theoretical conversion efficiency, low production cost and a simple production process have received great attention in recent years. For CdSe-sensitized cells, the most significant defect of CdSe is that it has the weak absorption between 550 and 600 nm and no absorption after 650 nm, so it is crucial to find a wide spectrum photosensitizer to make up for the defect. Here, wide spectrum and pure inorganic Donor–Acceptor (D–A) Type Polyoxometalate (POM) K6H4[α-SiW9O37Co3(H2O)3]·17H2O (denoted as T) is firstly introduced into QDSCs as a collaborative cosensitizer with CdSe. The T has a visible characteristic peak centering between 550 and 600 nm, and also has stronger absorption after 650 nm, which could make up for the defect of CdSe to constitute a wide spectrum of absorption. The fluorescence spectrum, surface photovoltage spectrum, ultraviolet photoelectron spectroscopy spectrum and solid diffuse spectrum were used to explore the photosensitivity of T. In addition, the D–A type POM can act as a good intermediate for the injection of electrons and improve the visible photocurrent response; meanwhile, it can obviously reduce the dark current and increase the electron lifetime, which can solve the problem about the high recombination at the QD/TiO2/electrolyte interface. In general, the best photovoltaic performance of T and CdSe cosensitized solar cells is increased to 6.59% (Jsc = 18.37 mA cm−2, Voc = 0.57 V, FF = 0.63), which is improved by 32.33% compared to those of the pure CdSe-sensitized cells (Jsc = 16.20 mA cm−2, Voc = 0.50 V, FF = 0.61, η = 4.98%).
Co-reporter:Chun-Hui Shan, Hong Zhang, Wei-Lin Chen, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 9) pp:NaN3303-3303
Publication Date(Web):2016/01/22
DOI:10.1039/C5TA10601J
A pure inorganic donor–acceptor (D–A) type polyoxometalate K6H4[α-SiW9O37Co3(H2O)3]·17H2O (SiW9Co3)/reduced graphene oxide (RGO) nanocomposite was employed to dye-sensitized solar cells (DSSCs) for the first time, building up a wide spectrum for the photoanode of a DSSC. Raman, XRD, TEM, and EDS have proved that SiW9Co3 was loaded on RGO, and then the SiW9Co3/RGO doped nanocomposite in P25 was applied to be the photoanode of the DSSCs. In this paper the performance of SiW9Co3/RGO-3@P25 is the best. The Jsc of pure P25 is 13.74 mA cm−2, Voc is 0.679 V, FF is 0.598 and η is 5.37%, while the Jsc of SiW9Co3/RGO-3@P25 is 17.5 mA cm−2, Voc is 0.705 V, FF is 0.558 and η is enhanced to 6.88%, which is 28.05% higher than for a pure P25-based cell in a DSSC. OCVD indicates that SiW9Co3/RGO can delay the electron–hole recombination. In a Bode plot the electron lifetimes of SiW9Co3/RGO-3@P25 and P25 are 4.86 ms and 3.81 ms respectively, which also further clarifies that the SiW9Co3/RGO doped nanocomposite can extend the lifetime of electrons and also plays an important role in the photoanode of the DSSCs. This result is beneficial to the application of DSSCs in future industry.
Co-reporter:Yanfei Qi, Yangguang Li, Enbo Wang, Zhiming Zhang and Song Chang
Dalton Transactions 2008(Issue 17) pp:NaN2345-2345
Publication Date(Web):2008/03/19
DOI:10.1039/B713115A
Five new organic–inorganic assemblies, [Co(en)3][Co(en)2As8V14O42(H2O)]·16H2O (1), [Ni(Meen)3]4[Ni(Meen)2][As8V14O42(NO3)]2·8H2O (2), [Cd(en)3][Cd(phen)(en)(H2O)2][(en)CdAs8V13O41(H2O)]·1.5H2O (3), [Cd(phen)2(en)]2[(phen)CdAs8V13O41(H2O)]·21H2O·phen (4), [Zn(en)2]2[(bpe)2Zn2As8V12O40(H2O)] (5) (en = ethylenediamine, Meen = 1,2-diaminopropane, phen = 1,10-phenanthroline, and bpe= 1,2-bis(4-pyridyl)ethylene) have been synthesized and characterized. Among them, compounds 1 and 2 are constructed from the [As8V14O42] cluster; compounds 3 and 4 are constructed from the Cd-substituted polyoxovanadate [CdAs8V13O41] cluster, while compound 5 consists of bizinic-substituted polyoxovanadate [Zn2As8V12O40] building units. It can be assumed that the metal ions used in these reaction systems play a crucial role in controlling the formation of the arsenic–vanadium–cluster backbones, and further leading to the formation of hybrids based on these clusters.
Co-reporter:Weilin Chen, Yangguang Li, Yonghui Wang, Enbo Wang and Zhiming Zhang
Dalton Transactions 2008(Issue 7) pp:NaN867-867
Publication Date(Web):2007/12/04
DOI:10.1039/B717419E
A new polytungstoarsenate-based 3d–4f heterometallic aggregate has been synthesized, consisting of three {α-AsW10O38} fragments bridged by three {Fe–(µ3-O)3–Ce} heterometallic clusters.
Co-reporter:Zhiming Zhang, Jia Liu, Enbo Wang, Chao Qin, Yangguang Li, Yanfei Qi and Xinlong Wang
Dalton Transactions 2008(Issue 4) pp:NaN468-468
Publication Date(Web):2007/11/06
DOI:10.1039/B712903C
Two new compounds constructed from tetra-Ni-substituted sandwich-type polyoxometalates functionalized by organic groups, (NH4)2[Ni4(enMe)8(H2O)2Ni4(enMe)2(PW9O34)2]·9H2O (enMe = 1,2-diaminopropane) (1) and Na2[H6N2(CH2)6]2{Ni4[H4N2(CH2)6]2(H2PW9O34)2}·7H2O (2), have been successfully synthesized under hydrothermal conditions. Single-crystal X-ray diffraction analysis is carried out on these two compounds (1 and 2), which both crystallize in the triclinic system. Compound 1 represents the first example of a 2D layer structure consisting of the sandwich-type polyoxoanions with six supporting [Ni(enMe)2]2+ moities and two organic functionalized groups. Compound 2 exhibits a 1D chain-like structure based on sandwich-type polyoxoanions and sodium cations, which are further connected into a 2D layer structure viahydrogen-bonding interactions between the 1,6-hexanediamine molecules and the sandwich-type [Ni4(H4N2(CH2)6)2(H2PW9O34)2]6– polyoxoanions. A magnetic study of the two compounds indicates that intramolecular ferromagnetic Ni–Ni interactions exist in the tetranuclear metal cluster.
Co-reporter:Guoying Sun, Yaping Chang, Siheng Li, Qiuyu Li, Rui Xu, Jianmin Gu and Enbo Wang
Dalton Transactions 2009(Issue 23) pp:NaN4487-4487
Publication Date(Web):2009/04/01
DOI:10.1039/B901133A
Two efficient pH-responsive oral delivery systems have been fabricated through a dative bonding between the amino-functionalized mesoporous silica materials, including MCM-41-type mesoporous silica nanospheres (MMSNs) and bimodal mesoporous silica microspheres (BMSMs), and an antitumour-active polyoxometalate K8H2[Ti(H2O)]3SiW9O34 (Ti3SiW9). The Ti3SiW9 loaded in the pores of MMSNs and BMSMs are up to 23.72 wt% and 28.69 wt% at pH 6.5, respectively. Both delivery systems reveal an increase of Ti3SiW9 release under mildly alkaline conditions, while zero premature release is observed under acidic and neutral conditions, making them ideal for use as a new class of colon-specific oral delivery systems. Importantly, these systems provide very promising possibilities for many medical applications that require an increase or decrease in the rate of drug release, depending on disease evolution. Upon incorporation into mesoporous silica materials, the antitumour activity of Ti3SiW9 against Ls-174-T was improved from 0.8 mg mL−1 to 0.186 and 0.102 mg mL−1 for Ti3SiW9@MMSN-NH2 and Ti3SiW9@BMSM-NH2, respectively.
Co-reporter:Ling Yuan, Chao Qin, Xinlong Wang, Yangguang Li and Enbo Wang
Dalton Transactions 2009(Issue 21) pp:NaN4175-4175
Publication Date(Web):2009/04/22
DOI:10.1039/B818535B
A series of novel organic–inorganic assemblies, {Ag3(2,2′-bipy)2(4,4′-bipy)2}{Ag(2,2′-bipy)2}{Ag(2,2′-bipy)}[AlW12O40]·H2O (1), [Ag(phen)2]3[Ag(phen)3][AlW12O40]·H5O2 (2) and {Co(2,2′-bipy)3}3{Co(H2O)(2,2′-bipy)2[AlW12O40]}2·H2O (3) (2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine, phen = 1,10-phenanthroline) constructed from Keggin-type [AlW12O40]5− polyoxoanion and transition-metal organoamine subunits, have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis (TGA), electrochemical properties and single-crystal X-ray diffraction. A remarkable aspect of compound 1 is that there exists four types of coordination configurations for the five crystallographically independent Ag centers, and this phenomenon has never been observed in polyoxometalate (POM) chemistry. The trimeric {[Ag(phen)2]3}3+ cluster in compound 2 is firstly extended into an interesting one-dimensional wave-like array and then is further extended into a three-dimensional supramolecular network with the [AlW12O40]5−clusters residing in the interstices of this three-dimensional framework. The most striking structure feature of compound 3 is that three water molecules linearly arrange between the adjacent monosupporting {Co(H2O)(2,2′-bipy)2[AlW12O40]}3− anions, leading to the formation of the three-dimensional supramolecular network by weak interactions.
Co-reporter:Shiwei Lin, Wenli Liu, Yangguang Li, Qiong Wu, Enbo Wang and Zhiming Zhang
Dalton Transactions 2010 - vol. 39(Issue 7) pp:NaN1744-1744
Publication Date(Web):2009/12/21
DOI:10.1039/B905079E
Ionothermal synthesis was applied to the formation of polyoxometalates (POMs) and two new compounds [EMIM]8Na9[WFe9(µ3-O)3(µ2-OH)6O4H2O(SiW9O34)3]·7H2O (1, [EMIM]8Na9[1a]·7H2O, EMIM = 1-ethyl-3-methylimidazolium) and [EMIM]4[SiMo12O40]·12H2O (2), have been successfully produced in the ionic liquid (IL) [EMIM]4Br. They were characterized by single-crystal X-ray diffraction, elemental analysis, UV-vis, IR and TG analysis. Furthermore, the magnetic properties of 1 and the electrochemical properties of 2 were studied. 1 is a high-nuclear transition metal substituted polyoxometalate (TMSP) and the unprecedented polyoxoanion of 1a is composed of three [α-SiW9O34]10− Keggin moieties connected by a {WFe9} cluster core. 2 is a heteropolyoxometalate with the polyoxoanion of α-Keggin type.
Co-reporter:Huaqiao Tan, Weilin Chen, Ding Liu, Yangguang Li and Enbo Wang
Dalton Transactions 2010 - vol. 39(Issue 5) pp:NaN1249-1249
Publication Date(Web):2009/11/23
DOI:10.1039/B912321K
Two new cantilever-type polyoxometalates Na5(NH4){VIV[(Mo2O6)CH3C(O)(PO3)2]2}·13H2O (1) and (NH4)4{VIV[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]2}·6H2O (2) have been synthesized and characterized by IR spectroscopy, UV-visible spectroscopy, elemental analysis, TG analysis, XPS, 31P NMR and single-crystal X-ray diffraction. The structure analysis reveals that the diphosphonate, hydroxyethylidene diphosphonic acid and alendronic acid as the scaffolds, have been grafted on the “S”-shaped polyoxoanions 1 and 2 respectively. The alkyl groups of the diphosphonates like arms hanged on the polyoxoanions form the cantilever-type polyoxometalates.
Co-reporter:Huaqiao Tan, Weilin Chen, Ding Liu, Xiaojia Feng, Yangguang Li, Aixue Yan and Enbo Wang
Dalton Transactions 2011 - vol. 40(Issue 33) pp:NaN8418-8418
Publication Date(Web):2011/07/19
DOI:10.1039/C0DT01729A
Two asymmetric polyoxomolybdates Na6{Mo2O5[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]2}·16H2O (1) and (NH4)7Na{MoO2[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]}4·H2O (2) have been synthesized by the reactions of alendronic acid with molybdate. Structure analysis revealed that the polyoxoanions 1 and 2 can be described as dimeric and tetrameric aggregates of the {MoO3[(Mo2O6)NH3CH2CH2CH2C(O)(PO3)2]} units respectively. Their tetrabutylammonium salts show efficient selective oxidation of benzyl alcohol to benzaldehyde with 72.5% and 81.5% benzyl alcohol conversion, and 87.1% and 82.4% benzaldehyde selectivity, respectively.
Co-reporter:Shuang Yao, Zhiming Zhang, Yangguang Li and Enbo Wang
Dalton Transactions 2010 - vol. 39(Issue 16) pp:NaN3889-3889
Publication Date(Web):2010/03/11
DOI:10.1039/B921261B
Reactions of hexavacant polyoxotungstates [H2P2W12O48]12− ({P2W12}) with transition-metal (TM), and alkali-metal ions lead to the isolation of two hexa-TM-containing polyoxotungstates Na15[Na3⊂{M(H2O)4}6{WO(H2O)}3(P2W12O48)3]·xH2O (M = Co2+, x = 109 for 1; M = Ni2+, x = 110 for 2). Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 both crystallized in the orthorhombic system, space group Cmcm, with lattice constants a = 21.353(3) Å, b = 32.114(3) Å, c = 33.848(4) Å, for 1; a = 21.643(6) Å, b = 31.870(6) Å, c = 33.861(7) Å for 2. Polyoxoanions [Na3⊂{M(H2O)4}6{WO(H2O)}3(P2W12O48)3]15− in 1 and 2 exhibit a crown-type structure composed of a [{WO(H2O)}3(P2W12O48)3]18- (abbreviated as {P6W39}) shell encapsulating six TM ions and three Na+ cations. Polyoxoanions 1 and 2 represent the first hexa-TM-containing {P2W12}-based trimeric POMs, which offer new examples with the potentially aqua-ligand-induced capability of “trapping” metal ions in the {P6W39} shell. Electrocatalytic studies show that compounds 1 and 2 display electrocatalytic activity to reduce nitrite.
Co-reporter:Qiong Wu, Wei-Lin Chen, Ding Liu, Chang Liang, Yang-Guang Li, Shi-Wei Lin and Enbo Wang
Dalton Transactions 2011 - vol. 40(Issue 1) pp:NaN61-61
Publication Date(Web):2010/11/22
DOI:10.1039/C0DT00884B
By combination of heteropolymolybdates and metal–Schiff-base complexes, two new organic–inorganic hybrid compounds {Mn(salen)2(H2O)2[AlMo6(OH)6O18]}[arg]·16H2O (1) and {Mn(salen)2(H2O)2[CrMo6(OH)6O18]}[arg]·11H2O (2) (salen = N,N′-ethylene-bis(salicylideneiminate) have been successfully isolated. Compounds 1 and 2 were structurally characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. To the best of our knowledge, compounds 1 and 2 represent the first single-crystal structures of metal–Schiff-base decorated polyoxometalates (POMs) compounds. Photocatalytic experiments indicated that both 1 and 2 exhibit high catalytic activity for photodegradation of RhB with UV irradiation. In addition, the magnetic properties of 1 were also investigated.
Co-reporter:Zhu-Jun Liu, Zhi-Ming Zhang, Hai Fu, Yang-Guang Li, Wei-Lin Chen, Hai-Hong Wu and En-Bo Wang
Dalton Transactions 2012 - vol. 41(Issue 38) pp:NaN11705-11705
Publication Date(Web):2012/08/01
DOI:10.1039/C2DT30742A
Two new {P8W48} wheel-based compounds, Na12Li16{[Cu(H2O)]2[Cu4(OH)4(H2O)8]2P8W48O184}·55H2O (1), and K4Na24Li10{(MoO2)2(P8W48O184)}·61H2O (2) have been synthesized by a conventional aqueous solution method, and characterized by UV, IR, TG analysis, XPRD, 31P NMR, XPS, single-crystal X-ray diffraction analyses, magnetic study and electrochemistry study. In compound 1, a wheel-type {P8W48} containing two {Cu4} clusters and two isolated Cu cations results in a 10-Cu-containing polyoxotungstate, which represents the first {P8W48}-based compound trapping two transition metal (TM) clusters in its inner cavity. Further, the polyoxoanion was connected by Na+ and Li+ cations into a 3D framework. Compound 2 is a 2-Mo-containing {P8W48}-based polyoxotungstate. Magnetic study indicates that antiferromagnetic interactions exist in compound 1.
Co-reporter:Ding Liu, Ying Lu, Yang-Guang Li, Hua-Qiao Tan, Wei-Lin Chen, Zhi-Ming Zhang and En-Bo Wang
Dalton Transactions 2013 - vol. 42(Issue 40) pp:NaN14453-14453
Publication Date(Web):2013/08/07
DOI:10.1039/C3DT51250A
Three trimeric polyoxovanadate based on 1:13 anions [MnV13O38]7− with lanthanide cations Ln3+ (Ln = La, Ce and Nd) and pyridine-3-carboxylic acid: HK3{[Ln(H2O)4]6[MnV13O38]3(SO4)2}·3(C6H6NO2)·nH2O (Ln = La 1, Nd 3; n = 33 for 1, 20 for 3), H2.5K1.5{[Ce(H2O)4]6[MnV13O38]3(SO4)2}·3(C6H6NO2)·20.5H2O (2) (C6H5NO2 = pyridine-3-carboxylic acid) have been synthesized and characterized by elemental analysis, IR spectroscopy, UV spectroscopy, TG analysis, XPRD, electrochemical analyses, magnetism and single-crystal X-ray diffraction. Compounds 1–3 are isostructural and crystallized in the hexagonal system, space group P63/m. Compounds 1–3 contain an unusual trimeric polyoxoanion [{Ln2MnV13O38}3(SO4)2]7−, representing the first polyoxovanadate-based trimeric aggregate with rare earth ions. The electrochemical and electrocatalytic properties of the compounds have been investigated. Magnetic studies indicate that antiferromagnetic interactions exist in the compounds.
Co-reporter:Jian-Qiang Shen, Shuang Yao, Zhi-Ming Zhang, Hai-Hong Wu, Tian-Zhan Zhang and En-Bo Wang
Dalton Transactions 2013 - vol. 42(Issue 16) pp:NaN5817-5817
Publication Date(Web):2013/01/31
DOI:10.1039/C3DT32855D
An unprecedented organic–inorganic hybrid germanoniobate compound Na4[Cu(en)2(H2O)2]5[Na6Ge8Nb32O108H8(OH)4]·41H2O (1) was synthesized under the hydrothermal condition. In compound 1, the {Nb16} cage containing four {GeO4} tetrahedra in its internal cavity results in a heteropolyniobate anion [H4Ge4Nb16O54(OH)2]10− ({Ge4Nb16}), which is connected by a {Na6} cluster into the first germanoniobate-based sandwich-type structure. Further, the sandwich germanoniobates are connected by [Na2Cu(en)2O6H8] groups into a porous network with one dimensional channels along the a-axis. Photocatalytic study reveals that compound 1 exhibits good photocatalytic activity for the degradation of methylene blue.
Co-reporter:Hai-Hong Wu, Shuang Yao, Zhi-Ming Zhang, Yang-Guang Li, You Song, Zhu-Jun Liu, Xin-Bao Han and En-Bo Wang
Dalton Transactions 2013 - vol. 42(Issue 2) pp:NaN346-346
Publication Date(Web):2012/10/26
DOI:10.1039/C2DT32318D
The heterometallic appended {MMnIII4} (M = Dy3+ and K+) cubanes were firstly trapped by two diamagnetic POM shells, which were robust enough to construct inorganic crystalline tubular materials. Magnetic study reveals the presence of a SMM-like slow magnetic relaxation feature in the heterometallic cluster-containing POM.
Co-reporter:Zhi-Ming Zhang, Xiaopin Duan, Shuang Yao, Zhishu Wang, Zekai Lin, Yang-Guang Li, La-Sheng Long, En-Bo Wang and Wenbin Lin
Chemical Science (2010-Present) 2016 - vol. 7(Issue 7) pp:NaN4229-4229
Publication Date(Web):2016/03/09
DOI:10.1039/C5SC04408A
We report the crystallization of homochiral polyoxometalate (POM) macroanions {CoSb6O4(H2O)3[Co(hmta)SbW8O31]3}15− (1, hmta = hexamethylenetetramine) via the counter cation-mediated chiral symmetry breaking and asymmetric autocatalytic processes. In the presence of low Co2+ concentrations both Δ- and Λ-enantiomers of 1 formed in the reaction, crystallizing into the racemic crystal rac-1. At a high Co2+ concentration, the polyoxoanion enantiomers showed a high level of chiral recognition via H-bonding interactions to crystallize into enantiopure crystals of Δ- or Λ-[Co(H2O)6{CoSb6O4(H2O)3[Co(hmta)SbW8O31]3}]13−. During crystallization, a microscale symmetry-breaking event and a nonlinear asymmetric autocatalysis process make the enantiomers crystallize in different batches, which provides an opportunity to isolate the homochiral bulk materials. The defined structures of the racemic and homochiral crystals thus provide a molecular-level illustration that H-bonding interactions are responsible for such high-level chiral recognition, in a process similar to the supramolecular chirality frequently observed in biology. These POM macroanions showed a high cytotoxicity against various cancer cells, particularly ovarian cancer cells. The antitumor activity of these compounds resulted at least in part from the activation of the apoptotic pathways, as shown by the flow cytometry, Annexin V staining, DNA ladder, and TUNEL assay, likely by blocking the cell cycle and complexing with proteins in cells. The POM macroanions reported herein provide promising and novel antitumor agents for the potential treatment of various cancers.
Co-reporter:Huan Zhang, Ying Lu, Zhiming Zhang, Hai Fu, Yangguang Li, Dirk Volkmer, Dmytro Denysenko and Enbo Wang
Chemical Communications 2012 - vol. 48(Issue 58) pp:NaN7297-7297
Publication Date(Web):2012/06/07
DOI:10.1039/C2CC32120C
A 12-connected metal–organic framework based on an unprecedented cyclic Cu12 cluster with a large internal cavity has been prepared, and its cation exchange property was determined.
Co-reporter:Ding Liu, Ying Lu, Hua-Qiao Tan, Wei-Lin Chen, Zhi-Ming Zhang, Yang-Guang Li and En-Bo Wang
Chemical Communications 2013 - vol. 49(Issue 35) pp:NaN3675-3675
Publication Date(Web):2013/03/15
DOI:10.1039/C3CC40990B
Purely inorganic porous frameworks using catalytically active [MnV13O38]7− clusters as nodes and rare earth ions as linkers have been successfully prepared. The POM-based porous framework is a kind of multifunctional material, which exhibits selective adsorption behavior and remarkable catalytic activity for the heterogeneous oxidation of sulfides.
Co-reporter:Jian-Qiang Shen, Ying Zhang, Zhi-Ming Zhang, Yang-Guang Li, Yan-Qing Gao and En-Bo Wang
Chemical Communications 2014 - vol. 50(Issue 45) pp:NaN6019-6019
Publication Date(Web):2014/04/17
DOI:10.1039/C3CC49245A
Two phosphoniobate-based 3D frameworks were firstly constructed using the hexa-capped Keggin polyoxoniobates [PNb12O40(VO)6]3− and copper cations. Photocatalytic studies indicated that the hybrid materials exhibit photocatalytic hydrogen evolution activity.
Co-reporter:Xiao-Jing Sang, Jian-Sheng Li, Lan-Cui Zhang, Zai-Ming Zhu, Wei-Lin Chen, Yang-Guang Li, Zhong-Min Su and En-Bo Wang
Chemical Communications 2014 - vol. 50(Issue 93) pp:NaN14681-14681
Publication Date(Web):2014/10/08
DOI:10.1039/C4CC06211F
Two novel open-chain carboxyethyltin decorated sandwich-type germanotungstates have been successfully synthesized. They could markedly increase the electrocatalytic activity of single-walled carbon nanotubes toward triiodide reduction when assembled into composite electrodes, which have shown a conversion efficiency of 6.32% that is comparable to that of Pt electrodes (6.29%) when used as counter electrodes in dye-sensitized solar cells.
Co-reporter:Zhi-Ming Zhang, Shuang Yao, Yang-Guang Li, Hai-Hong Wu, Yong-Hui Wang, Mathieu Rouzières, Rodolphe Clérac, Zhong-Min Su and En-Bo Wang
Chemical Communications 2013 - vol. 49(Issue 25) pp:NaN2517-2517
Publication Date(Web):2013/02/06
DOI:10.1039/C3CC38981B
A polyoxometalate (POM)-based {MnIV2MnIII6MnII4} complex with single-molecule magnet (SMM) behaviour was prepared, exhibiting the largest known Mn nuclearity and the most Mn valence states in the POM-based SMM family.
Co-reporter:Qiong Wu, Yang-Guang Li, Yong-Hui Wang, Rodolphe Clérac, Ying Lu and En-Bo Wang
Chemical Communications 2009(Issue 38) pp:
Publication Date(Web):
DOI:10.1039/B909246C
Co-reporter:Chun-Chen Yuan, Shi-Ming Wang, Wei-Lin Chen, Lin Liu, Chao Qin, Zhong-Min Su and En-Bo Wang
Dalton Transactions 2014 - vol. 43(Issue 4) pp:NaN1497-1497
Publication Date(Web):2013/11/12
DOI:10.1039/C3DT52676C
Two Anderson-type heteropolyanion-supported copper phenanthroline redox couples have been successfully introduced into dye-sensitized solar cells, which can significantly increase the short-circuit photocurrent, open-circuit voltage and the conversion efficiency by 2.2 times, 26.8% and 3.93 times respectively, compared to the pristine copper phenanthroline redox couple.
Co-reporter:Shi-Ming Wang, Lin Liu, Wei-Lin Chen, En-Bo Wang and Zhong-Min Su
Dalton Transactions 2013 - vol. 42(Issue 8) pp:NaN2695-2695
Publication Date(Web):2012/12/11
DOI:10.1039/C2DT32403B
Polyoxometalate–TiO2 composites have been successfully introduced into the photoanode of dye-sensitized solar cells to reduce the recombination of the electrons, which results in a longer electron lifetime. The performance of the cells with the polyoxometalate-modified photoanode is better than the cell with a pure P25 photoanode. The effect of the polyoxometalate was studied by electrochemical impedance spectroscopy and open-circuit voltage decay measurement. The results show that the electron lifetime becomes longer following an increase in the amount of the polyoxometalate.
Co-reporter:Sha-Sha Xu, Wei-Lin Chen, Yan-Hua Wang, Yang-Guang Li, Zhu-Jun Liu, Chun-Hui Shan, Zhong-Min Su and En-Bo Wang
Dalton Transactions 2015 - vol. 44(Issue 42) pp:NaN18562-18562
Publication Date(Web):2015/09/16
DOI:10.1039/C5DT02992A
A di-vanadium-substituted Lindqvist-type polyoxometalate [Cu(C12H8N2)2]2[V2W4O19]·4H2O (1) was hydrothermally synthesized and characterized structurally by single crystal X-ray diffraction analysis. X-ray photoelectron spectroscopy and energy disperse spectroscopy tests further prove the existence of vanadium. Ultraviolet photoelectron spectroscopy and density functional theoretical studies indicate that the energy level of 1 matches well with the conduction band of the TiO2. Furthermore, considering the semiconductor-like nature of 1 and the introduction of transition metal element Cu synchronously extends the absorption to the visible region, which should also be beneficial to the photovoltaic device performance. 1-Doped TiO2 composites (denoted as 1@TiO2) have been successfully fabricated by a simple sol–gel method, and introduced into the dye-sensitized solar cells (DSSCs) as co-sensitizers in N719-sensitized photoanodes by mixing 1@TiO2 with P25 nanoparticles with different weight ratios to enhance the photoelectric conversion efficiency. The investigations show that the DSSC assembled with 1@TiO2/19P25 photoanode has the best performance and the overall improvement of the efficiency is 21.6% compared with pure P25. Furthermore, the electrochemical impedance spectroscopy and open-circuit voltage decay investigations show that the cosensitization of 1 and N719 can promote electron transfer and restrain charge recombinations in the DSSCs, resulting in a longer electron lifetime.
Co-reporter:Qing Lan, Jun Zhang, Zhi-Ming Zhang, Ying Lu and En-Bo Wang
Dalton Transactions 2013 - vol. 42(Issue 47) pp:NaN16607-16607
Publication Date(Web):2013/09/10
DOI:10.1039/C3DT51722E
Two new porous frameworks [Ni(bix)2][VW12O40]·(H2bix)·H2O (1) and [Co(bix)2][VW12O40]·(H2bix)·2H2O (2) (bix = 1,4-bis(imidazol-1-ylmethyl)-benzene) composed of Keggin polyoxometalates (POMs) and metal–organic coordination polymer sheets have been successfully obtained, and characterized by elemental analysis, IR spectra, thermal gravimetric analysis, and single crystal X-ray diffraction. Structural analysis reveals that the 2D metal–organic coordination polymer sheets in the two compounds are constructed from the transition-metal (TM) cations and the flexible N-donor ligand bix, which are further pillared by POM clusters into the 3D porous frameworks. Powder X-ray diffraction (PXRD) patterns of 1 indicate the structural integrity of the framework in aqueous solution with a wide pH range of 1 to 11, and in common organic solvents (methanol, ethanol and DMF). Photocatalytic studies indicate that compounds 1 and 2 are not only active photocatalysts for degradation of rhodamine B (RB), but very stable and easily separated from the photocatalytic system for reuse as well.
Co-reporter:Shuang-Shuang Guo, Chao Qin, Yang-Guang Li, Ying Lu, Zhong-Min Su, Wei-Lin Chen and En-Bo Wang
Dalton Transactions 2012 - vol. 41(Issue 8) pp:NaN2230-2230
Publication Date(Web):2012/01/03
DOI:10.1039/C2DT11897A
A long-term stable Pt counter electrode modified by POM-based multilayer film has been fabricated by the electrochemical deposition method, which can markedly increase short-circuit photocurrent, open-circuit voltage and the conversion efficiency when used in dye-sensitized solar cells (DSSCs).
Co-reporter:Zhi-Ming Zhang, Yang-Guang Li, Shuang Yao and En-Bo Wang
Dalton Transactions 2011 - vol. 40(Issue 24) pp:NaN6479-6479
Publication Date(Web):2011/05/19
DOI:10.1039/C1DT10133A
Two nanosized hexameric polyoxometalate-based solid state assemblies (H2en)6Na15K9[Dy6Fe6(H2O)12(SiW10O38)6]·34H2O (1) and K13Na17[H2en]3[Tb6Fe6(H2O)12(SiW10O38)6]·40H2O (2) (en = 1,2-ethylenediamine), decorated by six [Ln-(μ3-O)3-Fe] 3d–4f heterometallic clusters, have been synthesized by the hydrothermal method, and characterized by IR, element analysis, magnetic studies and the single-crystal X-ray analyses. The detailed study of the synthetic conditions reveals that the use of the organic ligands, pH value and the reaction temperature all play important roles in the synthesis of the 3d–4f heterometallic POMs. Magnetic study suggests the presence of antiferromagnetic interactions in these two compounds.
Co-reporter:Zhen-Li Wang, Hua-Qiao Tan, Wei-Lin Chen, Yang-Guang Li and En-Bo Wang
Dalton Transactions 2012 - vol. 41(Issue 33) pp:NaN9884-9884
Publication Date(Web):2012/06/22
DOI:10.1039/C2DT30663H
A new dimer polyoxoniobate [Cu(en)2]11K4Na2[KNb24O72H9]2·120H2O (1) has been synthesized and systematically characterized. Visible light photocatalytic H2 evolution activity was researched with 1 as the visible-light photosensitizer and catalyst, cobaloximes [CoIII(dmgH)2pyCl] as the co-catalysts, and triethylamine (TEA) as the sacrificial electron donor.
Co-reporter:Lan-Cui Zhang, Shu-Li Zheng, Han Xue, Zai-Ming Zhu, Wan-Sheng You, Yang-Guang Li and Enbo Wang
Dalton Transactions 2010 - vol. 39(Issue 14) pp:NaN3371-3371
Publication Date(Web):2010/02/22
DOI:10.1039/B925822A
The reaction of Cl3Sn(CH2)2COOCH3, [H2P2W12O48]12− and WO42− in acetate buffer solution led to the hydrolysis of estertin into a carboxyethyltin group and the assembly of a new tetra(organotin)-decorated boat-like polyoxometalate.
Co-reporter:Dan Xu, Wei-Lin Chen, Jian-Sheng Li, Xiao-Jing Sang, Ying Lu, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 19) pp:NaN10178-10178
Publication Date(Web):2015/03/31
DOI:10.1039/C5TA01578B
SiW11V/graphene nanocomposite was first prepared and introduced into TiO2 film. It showed a significant photocurrent response, which can be attributed to the photoinduced electrons of SiW11V. This work provides a promising strategy for exploring POMs sensitizers with lower energy levels than the CB of TiO2.
Co-reporter:Shi-Ming Wang, Lin Liu, Wei-Lin Chen, Zhi-Ming Zhang, Zhong-Min Su and En-Bo Wang
Journal of Materials Chemistry A 2013 - vol. 1(Issue 2) pp:NaN220-220
Publication Date(Web):2012/11/15
DOI:10.1039/C2TA00486K
We explore a new method to prepare polyoxometalate-based electrochromic (EC) smart windows. It is a simple and low cost process to prepare EC films by a solution-based electrodeposition method. The polyoxometalate-based EC smart windows exhibit high transparency in the bleached state, good optical contrast, long durability, and high coloration efficiency.
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![Tungstate(10-), [m9-[orthosilicato(4-)-kO:kO:kO:kO':kO':kO'':kO'':kO''':kO''']]pentadeca-m-oxopentadecaoxonona-, sodium (1:10)](http://img.cochemist.com/ccimg/64700/64684-57-7_b.png)
![Tungstate(3-),tetracosa-m-oxododecaoxo[m12-[phosphato(3-)-kO:kO:kO:kO':kO':kO':kO'':kO'':kO'':kO''':kO''':kO''']]dodeca-,hydrogen (1:3)](http://img.cochemist.com/ccimg/1400/1343-93-7.png)
![Tungstate(3-),tetracosa-m-oxododecaoxo[m12-[phosphato(3-)-kO:kO:kO:kO':kO':kO':kO'':kO'':kO'':kO''':kO''':kO''']]dodeca-,hydrogen (1:3)](http://img.cochemist.com/ccimg/1400/1343-93-7_b.png)
