A new electron transfer type photoactive host–guest supramolecule was constructed by introducing (CH3)2NH2+ cations to the MOF framework. The resulting compound 1 exhibits reversible photochromic property without using photochromic components, resulting from photoinduced electron-transfer between the electron-rich anionic framework and the electron-deficient guest ions. In addition, a photoluminescence “on/off switch” occurs during the coloration–decoloration process. The raw materials are non-poisonous and harmless, hence compound 1 may be more cost-effective, clean, and harmless to the heath than existing photochromic materials.

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.

Three new POM-based pillar-layer CuI coordination polymers (CPs), CuI12Cl(trz)8[PW12O40] (1), CuI12Cl(trz)8[PMo12O40] (2) and CuI12Cl(trz)8[HSiW12O40] (3) (trz = 1,2,4-triazole), have been hydrothermally synthesized. Characterized by single-crystal X-ray diffraction analyses, compounds 1–3 are isostructural, and copper ions coordinate with trz to form double layers with the help of Cl ions, which are supported by POMs to a 3D framework with continuous channels. The same two frameworks interwine to form a 3D two-fold interpenetrating network. The compounds display high heat stability and excellent acid and alkali resistance. Ultraviolet-vis diffuse-reflectance spectra suggest that compounds 1–3 exhibit their nature of semi-conductivity. Thus, reactions of photocatalytic degradation of organic dye were performed, and its relevant photocatalytic mechanism was also finely investigated. All the title compounds show efficient visible-light-driven photocatalytic activities in the degradation of organic dyes. Moreover, hydroxyl radicals (˙OH) are proved to play a crucial role in visible photocatalytic degradation reaction.

A cobalt-based polyoxometalate, (STA)10[Co4(H2O)2(PW9O34)2] (SEP) (STA = stearyltrimethylammonium), was prepared by ionic exchange of K10[Co4(H2O)2(PW9O34)2] and STA·Cl. SEP was approved as an effective catalyst for desulfurization of fuels in [Bmim]PF6 by using aqueous H2O2 as oxidant in an extraction and catalytic oxidative desulfurization system (ECODS). The optimum desulfurization conditions were obtained: DBT could be completely removed with only O/S molar ratio of 4 in 40 min at 60 °C in a three-liquid-phase micro-emulsion system. The catalyst could be recycled conveniently and reused at least six times without significantly reducing the desulfurization efficiency. Therefore, this catalyst shows excellent regeneration and a good prospect for industrial application. For different substrates, the efficiencies of sulfur removal decreased in the following order: DBT > 4,6-DMDBT > BT under the same conditions. Furthermore, the catalytic oxidation desulfurization mechanism of SEP was studied.

•A new POM-based CuI coordination polymers have been hydrothermally synthesized.•Compound 1 displays high heat stability, acid and alkali resistance.•It shows efficient visible-light-driven photocatalytic activities in the degradation of organic dyes.A new coordination polymer (CP), [(PW12O40)2CuI6(trz)6]·H2O (1), has been prepared by hydrothermal method. Six Cu(I) ions are bridged by six trz molecules and six surface oxygen atoms of PW12 to generate a wheel-type CuI6 cluster, and each CuI6 cluster was capped with two PW12 anions to form a dumbbell-like second building block (SBB). 1 can remain intact in solution with pH range from 1 to 10, boiling water and boiling organic solvents, which shows the high heat stability, acid and alkali resistance. It also shows efficient visible-light-driven photocatalytic activities in the degradation of organic dyes.A new 3D POM-based Cu(I) coordination polymer has been successfully prepared by in-situ hydrothermal reaction. Compound 1 shows remarkably stability and efficient photocatalytic activities in the degradation of organic dyes.

Two new 3D coordination polymers, namely, [CuII3Cl(BBTZ)5(BW12O40)(H2O)2]·6H2O (1) and [CuI3CuII(BBTZ)5(BW12O40)(H2O)]·H2O (2) (BBTZ = 1,4-bis(1,2,4-triazol-1-lmethyl)benzene), have been successfully synthesized under hydrothermal conditions. Compound 1 is a 3D architecture with octa-nuclear water clusters while compound 2 is a 1D + 3D → 3D interpenetrated framework, which represents the first example of a POM-based coordination polymer with the co-existence of self-catenation and poly-threading. The structure–property correlations between the title compounds have been discussed. Compound 2 with narrow band-gap size exhibits more favorable efficiency of photocatalytic activity under visible light irradiation than compound 1.

•Three novel Lanthanide coordination polymers are reported.•A coordination mode of benzene-1,2,4,5-tetracarboxylic acid is first reported.•Scarce hexamer water clusters are reported.•A topological type of sqc37 is first reported for a coordination network.Three unprecedented high-connected 3D lanthanide coordination polymers based on benzene-1,2,4,5-tetracarboxylic acid (H4bta), {[Ln2(bta)1.5(H2O)4] · 3H2O}n (Ln = La (1) and Ce (2)) and [Pr(bta)0.5(H2bta)0.5(H2O)]n (3), have been synthesized under hydrothermal conditions. Complexes 1 and 2 show trinodal (4,4,10)-connected 3D network structures consisting of tetranuclear metal clusters bridged by bta4 − ligands, and a chair conformation hexamer water cluster can be found within the cage enclosed by eight neighboring tetranuclear metal clusters in the two complexes. While 3 consists of 2D {Pr(bta)0.5}n layers linked by H2bta2 − ligands, resulting in an unprecedented trinodal (4,6,10)-connected 3D topological network. The organic ligand exhibits five kinds of coordination modes, in which one of them is reported for the first time. Moreover, the luminescent properties of 1–3 have also been investigated.Two kinds of unprecedented high-connected 3D lanthanide–organic frameworks based on benzene-1,2,4,5-tetracarboxylic acid have been hydrothermally synthesized, and a chair conformation hexamer water cluster could be found within the cage enclosed by eight neighboring tetranuclear metal clusters in framework 1.

Four new POM-based hybrid compounds, namely, [Cu2(L1)3(H2O)2(P2W18O62)]·H2L1·4H2O (1), [Cu3(L2)6(P2W18O62)] (2), [Cu3(L3)5(H2O)(P2W18O62)]·4H2O (3) and [Cu3(L4)4(H2O)7(P2W18O62)]·26H2O (4) (L1 = 1,3-bis((1H-1,2,4-triazol-1-yl)methyl)benzene, L2 = 1,3-di(1H-1,2,4-triazol-1-yl)propane, L3 = 2-(1H-imidazol-2-yl)pyridine and L4 = 4-(1H-tetrazol-5-yl)pyridine), have been prepared under hydrothermal conditions. Compound 1 shows a three-dimensional (3D) framework with trinodal (4,4,6)-connected (3·42·5·66·72·83)(3·42·52·6)(3·42·62·7) topology. Compound 2 exhibits an unprecedented 3D framework with binodal (6,6)-connected SQC-888 topology. Compound 3 displays a two-dimensional (2D) structure with the existence of 2D → 3D interdigitation. In compound 4, {P2W18O62}6− is mono-supported by the linear tri-copper cluster {Cu3(H2O)L4}6+. In addition, the electrochemical properties and magnetic properties of 1–4 have also been studied.Graphical abstractFour POM-based hybrid compounds have been successfully prepared under hydrothermal conditions. Electrochemical analysis shows that 1–4-CPE display reversible redox properties and exhibit good electrocatalytic activity toward the reduction of nitrite. Magnetic study indicates an overall ferromagnetic interaction between the copper ions in 4.

•Six Cd(II) or Zn(II) coordination polymers mainly made up of flexible bbim or bbbm ligand were synthesized.•Weak interactions have important influence on extending structure dimension.•Complexes 1–5 based on different ligands form three types of 1D polymeric chains.•Organic polycarboxylate ligand benefit the construction of high dimensional complexes.Six new coordination polymers, [CdCl2(bbim)]n (1), [ZnCl2(bbbm)]n (2), [ZnCl(HCOO)(bbbm)]n (3), [Cd(PhCOO)2(bbim)]n (4), [Cd(PhCOO)2(bbbm)]n (5), and {[Zn(ip-OH)(bbim)]·DMF}n (6) [bbim = 1,1′-(1,4-butanediyl)bis(2-methylbenzimidazole), bbbm = 1,1′-(1,4-butanediyl)bis(benzimidazole), H2ip-OH = 5-hydroxylisophthalic acid], have been prepared and characterized by elemental analysis, infrared spectra and X-ray single-crystal diffraction. Complexes 1–5 have one-dimensional (1D) chain structures. Complexes 1, 3 and 4 possess similar 1D meso-helical chain structures, which are extended into 2D or 3D supramolecular network through intermolecular hydrogen-bonding, C–H⋯π and π⋯π interactions. Complexes 2 and 5 exhibit similar 1D infinite helical chains. The 1D chains further form a three-dimensional (3D) supramolecular structure through intermolecular hydrogen-bonding and π⋯π interactions in 2, but form a 2D supramolecular layer via C–H⋯π interactions in 5. Complex 6 possesses a 2D 44-sql network. Furthermore, luminescent properties and thermal stabilities of 1–6 were also investigated.Six Cd(II) or Zn(II) compounds have been synthesized. Complexes 1, 3 and 4 feature 1D meso-helical chain. Complexes 2 and 5 exhibit similar 1D infinite helical chains. Interestingly, these 1D chains display different metal ions arrangement. Complex 6 possesses a 2D 44-sql network.

A new MOF based on hetero pentanuclear clusters, [(CH3)2NH2]1.66[Cd1.84Na0.66(BDC)3]·DMF·0.5EtOH (1), has been prepared. Iodine adsorption studies reveal that 1 can reversibly adsorb iodine. Furthermore, electrochemical impedance spectroscopy (EIS) of 1⊃I2 shows that it has a relatively high conductivity at room temperature.

Two novel entangled POM-based coordination polymers (CPs), namely [Co2(L)5(H2O)2(SiW12O40)] (1) and [Cu2(L)3(H2O)2(SiW12O40)]·H2O (2) (L = 4,4′-bis((1H-1,2,4-triazol-1-yl)methyl)biphenyl), have been hydrothermally synthesized. Compound 1 presents an unprecedented 2D + 2D → 3D polypseudorotaxane motif. The fascinating self-catenated framework of compound 2 contains three types of helical chains. In addition, the photocatalytic properties of compounds 1 and 2 have also been investigated.

A new flexible coordination polymer based on the Keggin-type structure H3PW12O40·xH2O, [Cu(L)2(H2O)H(PW12O40)]·7H2O (1), has been prepared. The framework of 1 shows dynamic behavior accompanied with the removal/adsorption of guest water molecules. Compound 1 can remain intact even in 8 mol L−1 hydrochloric acid, dilute NaOH solution (pH = 12) and boiling water.

Three kinds of coordination polymers of lanthanide complexes with benzene dicarboxylato ligands, [Ln(L1)1.5(H2O)2]·H2O (H2L1 = 2,5-dibenzoylterephthalic acid; Ln = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), Tb (6), Dy (7)), [Ln(L2)(phen)(OH)] (H2L2 = 4,6-dibenzoylisophthalic acid; phen = 1,10-phenanthroline; Ln = Sm (8), Eu (9), Tb (10), Dy (11), Er (12), Yb (13)) and [Ln(L1)0.5(L2)(H2O)2] (Ln = Er (14), Ho (15)), were synthesized under hydrothermal conditions. They were characterized by elemental analysis, IR spectroscopy and thermogravimetric analysis. Their solid-state structures were determined by single-crystal X-ray diffraction. Complexes 1–7 are isostructural, each featuring the L1 connected dinuclear unit of Ln2O2(CO2)6 to produce a 6-connected 3D network with (412·63) topology. Isostructural complexes 8–13 possess 2D layer structures consisting of left- and right-handed helical chains that are further assembled into 3D supramolecular architectures through C–H⋯O, C–H⋯π and π⋯π interactions. Complexes 14 and 15 display 2D layer structures, and are further linked into 3D supramolecular architectures through C–H⋯O and π⋯π interactions. The luminescence properties of 3, 4 and 6–11 were investigated.

•1 is an unusual bicapped Keggin compound with two Cu atoms as caps.•2 is a tetrasupporting compound based on PMo12 modified by metal-organic fragments.•Both the 3D supramolecular structures include left- and right-handed helical chains.Two novel inorganic–organic hybrid compounds based on α-Keggin {PMo12O40} (PMo12) clusters, [CuI(bim)2]2{[CuII(bim)2]2[PMoVI9MoV3O40]} (1) and [CuI(mim)2]4[PMoVI11MoVO40]·H2O (2) (bim = benzimidazole, mim = 2-methylimidazole), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR spectrum, PXRD, elemental and TG analyses. Single crystal X-ray diffraction analyses reveal that both the two three-dimension (3D) supramolecular structures include left- and right-handed helical chains formed by modified polyoxometalate (POM) clusters via hydrogen bonds. 1 is an unusual bicapped Keggin compound with two Cu atoms as caps connecting with the POM via four bridging oxygen atoms, respectively. 2 is a tetrasupporting compound based on PMo12 cluster modified by four [CuI(mim)2]+ fragments. Photocatalytic activities of the two compounds have also been investigated in this paper.Graphical abstractTwo novel inorganic-organic hybrid compounds based on PMo12 were synthesized. 1 is an unusual bicapped compound with two Cu atoms as caps. 2 is a tetrasupporting compound based on PMo12 cluster modified by metal-organic fragments. Both the three-dimension supramolecular structures include left- and right-handed helical chains formed via hydrogen bonds.

A rare 4-connected neb framework has been constructed using a multi-carboxylic flexible ligand. It represents a unique 66 topology, which is evidently distinct from diamond and lonsdaleite topologies. In addition, the complex displays intriguing structural features of perpendicular right- and left-handed helical chains, as well as ferromagnetic interactions. Furthermore, the ferroelectric property is preliminarily discussed.

Two serious three-dimensional (3D) lanthanide organic frameworks, {[Ln(Hbidc)(ox)1/2(H2O)]·H2O}n [Ln = Pr (1), Nb (2) and Sm (3)] (H3bidc = Benzimidazole-5,6-dicarboxylic acid, H2ox = oxalic acid) and [Ln(Hbidc)(ox)1/2]n [Ln = Eu (4) and Gd (5)], have been synthesized solvothermally under different temperature conditions. Their structures have been characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra and thermogravimetric analysis. Structure analyses reveal that the five compounds exhibit similar 3D network structures that ox2− and Hbidc2− ligands showing the same coordination mode to link metal centers. The difference between the two kinds of compounds is that the coordination and lattice water molecules are absent in 4–5 due to the higher reaction temperature. Additionally, the luminescence properties of compounds 3 and 4 have been investigated in detail.Two series of 3D lanthanide organic frameworks have been synthesized solvothermally under different temperature conditions. Furthermore, the luminescence properties of compounds 3 and 4 have been investigated as well.Highlights► Two series of 3D lanthanide-organic frameworks have been synthesized solvothermally. ► The lattice and coordinated water molecules are absent under a higher temperature. ► They are constructed firstly by benzimidazole-5,6-dicarboxylic acid and oxalic acid.

Two new coordination polymers, {[Zn3L2.5(μ3-OH)(H2O)3]·4H2O}n (1) and [Zn2L1.5(μ3-OH)(4,4′-bpy)0.5]n (2) (H2L = 2,5-bis(4-methylbenzoyl)terephthalic acid, 4,4′-bpy = 4,4′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, TG, PXRD and single crystal X-ray diffraction. Complex 1 possesses a 2D double-layer configuration with 48·62 network constructed with trinuclear zinc(II) clusters and L2− ligands, which extends into a 3D architecture via O–H···O interactions between coordinated water molecules and lattice water molecules. Complex 2 is a uninodal 8-connected 3D framework with a 424·64 network based on tetranuclear zinc(II) clusters as nodes. Moreover, the luminescent properties of complexes 1 and 2 were also investigated.Two zinc(II) coordination polymers were synthesized through hydrothermal reaction. Complex 1 possesses a 2D double-layer configuration with 48·62 network based on trinuclear zinc(II) clusters. When the 4,4′-bpy was added into the reaction system, we obtained complex 2 which is a uninodal 8-connected 3D framework with a 424·64 network based on tetranuclear zinc(II) clusters as nodes.Highlights► Two original coordination polymers have been synthesized. ► Complex 1 possesses a 2D double-layer based on trinuclear zinc(II) clusters. ► Complex 2 is a novel 3D framework based on tetranuclear zinc(II) clusters. ► The luminescent properties of complexes 1 and 2 were investigated.

Four coordination compounds CuIICuI(O2N-ipO)(4,4′-bpy) (1), [CuII6(O2N-ipO)4btp(H2O)8]·6H2O (2), [CuII12(O2N-ipO)8(bth)4(H2O)10]·2H2O (3), and [CuII18(O2N-ipO)12(btp)3(H2O)18(EtOH)6]·13H2O (4) (4,4′-bpy = 4,4′-dipyridyl, btp = 1,3-bis(1,2,4-triazol-1-yl)propane, bth = 1,6-bis(1,2,4-triazol-1-yl)hexane and O2N-ipO = deprotonated 5-NO2-2-hydroxyisophthalic acid, Chart 1) were synthesized and crystallographically characterized. The common building unit [Cu2(O2N-ipO)2] (O2N-ipO = deprotonated 5-NO2-2-hydroxyisophthalate, in-situ formed in the reaction of 5-NO2-1,2,3-benzenetricarboxylic acid (O2N-btcH3) with CuCl2·2H2O under hydrothermal conditions) features a diamond-shaped dinuclear motif, in which two Cu atoms are bridged by the deprotonated 2-hydroxo groups from different O2N-ipO ligands. Compound 1 exhibits a three-dimensional (3D) wave-like structure composed of [CuII2(O2N-ipO)2]2− and [CuI2(4,4′-bpy)2]2+ subunits, while 2 displaying a 1D alternate double-chain structure based on units of [CuII2(O2N-ipO)2] and [CuIINO4]. Compounds 3 and 4 are discrete polynuclear species featuring a dodeca- and a octadeca-nuclear core based on units of [CuII2(O2N-ipO)2] and [CuIINOn], respectively. These compounds were further characterized by elemental analyses, FTIR, PXRD and thermogravimetric analyses. In addition, we studied their magnetic properties via direct current magnetic susceptibility measurements.Graphical abstractFour new coordination compounds of Cu(I/II) with 5-O2N-2-hydroxyisophthalate (O2N-ipO) ligand were synthesized and crystallographically characterized, and their magnetic properties were investigated. These complexes share the same dinuclear motif of [Cu2(O2N-ipO)2]2− whose ligand O2N-ipO was produced in situ during the hydrothermal synthesis using 5-O2N-1,2,3-benzenetricarboxylic acid as the starting ligand. Antiferromagnetic interactions were found in these compounds.Highlights► Four new compounds of Cu(I/II) with in-situ synthesized O2N-ipO from O2N-btcH3 were obtained. ► The necessity of Cu(II) for the in-situ ligand transformation was found during the synthesis. ► It was found that under high-pH conditions, O2N-btcH3 would undergo in-situ decarboxylation reaction. ► The magnetic characterization and simulation was performed based on diamond-shaped dinuclear motif [CuII2(O2N-ipO)2].

A novel three-dimensional (3D) coordination polymer [Cd(bta)0.5(N2H4)(H2O)]·H2O (1) (H4bta = benzene-1,2,4,5-tetracarboxylic acid; N2H4 = hydrazine) was synthesized hydrothermally and characterized by IR, elemental analysis, TGA and X-ray diffraction analysis. Compound 1 is the first example of 3D coordination compound containing trans-μ2-bridging ligand N2H4. In 1, Cadmium atoms are coordinated by bta4− ligands to form sinusoidal ruffling layers and the layer are further linked by hydrazine ligands into 3D network with a (83)(85·10) topology structure. In addition, the thermogravimetric analysis and fluorescent property of compound 1 have been investigated.A novel 3-D cadmium coordination compound was synthesized through hydrothermal reaction between cadmium salt and H4bta and N2H4·H2O. Hydrazine ligands and bta4− ligands are connected by Cd cations into simultaneously single-left and single-right-helice channels. Compound 1 would be an excellent candidate as light-emitter applications owing to its strong fluorescence emission.Research highlights► 1 is the first example that N2H4 ligands act as bridging ligands in the 3D network. ► H4bta is very popular to build coordination polymers with fascinating architectures. ► 1 would be an excellent candidate as light-emitter applications.

A new 3D sandwich-type MOF named [Zn3(bptc)1.5(H2O)4]·C2H5OH·2H2O (1) (H4bptc = biphenyl-2,5,2',5'-tetracarboxylic acid) was obtained by solvothermal reaction, which represents a rare trinodal (3, 4, 10)-connected topology network. Moreover, the thermal stability, UV–vis absorption spectra and photoluminescent properties of 1 have been investigated as well.A novel 3D zinc coordination complex was synthesized through solvothermal reaction between zinc salt and H4bptc. The complex 1 exhibits a rare (3, 4, 10)-connected topology network. In addition, the thermal stability, UV-vis absorption spectra and photoluminescent properties of 1 have been investigated.Highlights► New sandwich-type complex with trinuclear zinc(II) cluster and two kinds of discrete zinc(II) ions has been synthesized. ► Three-dimensional framework of [Zn3(bptc)1.5(H2O)4]·C2H5OH·2H2O exhibits a rare trinodal (3, 4, 10)-connected topology. ► The UV–vis absorption spectra and photoluminescent properties at room temperature has been investigated.

A novel eight-connected metal–organic framework, ZnII7(btc-NO2)4(bpp)2(μ3-OH)2(H2O)2 (H3btc-NO2 = 5-nitro-1,2,3-benzenetricarboxylate and bpp = 1,3-bi(4-pyridyl)propane, 1), has been hydrothermally synthesized and characterized by elemental analyses, FTIR, and X-ray diffraction. A rare U-shaped [Zn7O4(O2C)12N4] secondary building unit was found in 1, together with double parallel btc-NO2 anions and bpp flexibility ligands as links, resulting in an eight-connected heptanuclear-based uninodal 3D framework with 424.64 topology. Moreover, the thermal stability and luminescent property of 1 have been investigated as well.A novel eight-connected metal–organic framework, ZnII7(btc-NO2)4(bpp)2(μ3-OH)2(μ-OH2)2 (H3btc-NO2 = 5-nitro-1,2,3-benzenetricarboxylate and bpp = 1,3-bi(4-pyridyl)propane) (1), has been hydrothermally synthesized. Compound 1 is a 3D 8-connected network with CsCl topology, and exhibits strong fluorescence emission in solid state at ambient temperature.Research Highlights► The title complex is the first example of 8-connected framework based on heptanuclear zinc(II) clusters in the coordination chemistry of btc-NO2 and its derivatives. ► The title compound exhibits strong fluorescene emission in the solide state at ambient temperature. ► The title compound is thermal stable until the coordinated water molecules are decomposed up to 903K.

Several iridium complexes bearing chelating abnormal N-heterocyclic carbenes (NHCs) are shown to be active catalysts for transfer hydrogenation of ketones or enones, dehydrative C–C coupling between primary and secondary alcohols, and dehydrogenation of benzyl alcohol to benzyl benzoate. In the transfer hydrogenation of acetophenone, abnormal NHC complexes give higher activity than a normal analogue. Dehydrative C–C coupling reactions between primary and secondary alcohols result in β-alkylation of the secondary alcohols, using primary alcohols as the apparent alkylating reagents, and such reactions proceed with high yield and selectivity. These catalytic processes are known to involve metal-mediated temporary borrowing of hydrogen from alcohols and subsequent delivery of the hydrogen to CC and /or CO bonds.

Pt/C(a) catalysts are firstly prepared by modified impregnation method. In order to enhance the ability of Pt/C catalysts for methanol electrooxidation, H5PMo10V2O40 (PMV) is adsorbed on Pt/C catalysts to obtain the PMV-Pt/C catalysts. The Pt/C(a) and PMV-Pt/C are characterized by transmission electron microscopy (TEM) and X-ray diffractometry. It is shown that Pt particles with small average size are uniformly disperesed on carbon. Cyclic voltammetry and chronoamperometry show that the PMV-Pt/C catalysts exhibit excellent catalytic activity and stability for methanol electrooxidation.

Two new coordination polymers, [Co2(L)1.5(OH)(H2O)2]·2H2O (1) and [CoL(bpp)] (2) (H2L = 2,5-dibenzoylterephthalic acid and bpp = 1,3-bis(4-pyridyl)propane), have been synthesized and characterized by elemental analyses, IR spectra, and thermogravimetric analyses. Their structures were determined by single crystal X-ray diffraction analyses. Complex 1 exhibits a 3D framework assembled from tetra-nuclear cobalt-oxygen bridged by carboxylic O atoms with a (412·63) topology. Complex 2 possesses a 2D layered structure which extends into a 3D architecture via C–H···π interaction between propane proton and the phenyl ring or pyridine ring of an adjacent sheets. Furthermore, the magnetic properties of them are discussed.Two new coordination polymers, [Co2(L)1.5(OH)(H2O)2]·2H2O (1) and [CoL (bpp)] (2) (H2L1 = 2,5-dibenzoylterephthalic acid and bpp = 1,3-bis(4-pyridyl)propane), have been synthesized. Complex 1 exhibits a 3D framework assembled from tetranuclear cobalt-oxygen bridged by carboxylic O atoms with a (412·63) topology. 2 possesses a 2D layered structure which extends into a 3D architecture via C–H···π interaction.

A novel series of sulfonated poly(ether ether ketone ketone)s (SPEEKKs) with different degrees of sulfonation (Ds) were synthesized from 1,3-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene (1,3-SFBB-Na), 1,3-bis(4-fluorobenzoyl)benzene (1,3-FBB) and 3,3′,5,5′-tetramethyl-4,4′-biphenol (TMBP) by aromatic nucleophilic polycondensation. The chemical structures of SPEEKKs were confirmed by FT-IR spectroscopy and the Ds values of the polymers were calculated by 1H NMR and titration methods, respectively. The thermal stabilities of the SPEEKKs in acid and sodium forms were characterized by thermogravimetric analysis (TGA), which showed that SPEEKKs had excellent thermal properties at high temperatures. All the SPEEKK polymers were easily solution cast into tough membranes. Water uptakes, proton conductivities and methanol diffusion coefficients of the SPEEKK membranes were measured. Water uptake increased with Ds and temperature. Compared to Nafion, the SPEEKK-60, -70 and -80 membranes showed higher proton conductivities at 80 °C, while the other SPEEKK membranes showed relatively lower proton conductivities. This may be due to the different distribution of ion-conducting domains in membrane. However, these membranes showed lower methanol diffusions in the range of 8.32 × 10−9 to 1.14 × 10−7 cm2 s−1 compared with that of Nafion (2 × 10−6 cm2 s−1) at the same temperature. The membranes also showed excellent mechanical properties (with a Young's modulus > 1 GPa and a tensile strength > 40 MPa). These results indicate that the SPEEKK membranes are promising materials for use in direct methanol fuel cell (DMFC) applications.

PW11Sn/TiO2 (PW11Sn = (OTA)3PW11SnO39, OTA = octadecyl trimethyl ammonium) nanofibres with tunable rutile/anatase phase have been successfully prepared via combining with electrospinning and hydrothermal method. The crystal phase of TiO2 was influenced by the loading amount of PW11Sn and the desulfurization efficiency was related with the crystal phase of TiO2. When the loading amount of PW11Sn on TiO2 nanofibres was 50%, DBT could be completely removed using 0.02 g PW11Sn/TiO2 nanofibres as catalysts and [Bmim]PF6 as extraction agent at 60 °C within 20 min, when O/S value was 6:1. Furthermore, the influences of different morphologies and preparation methods for catalysts on desulfurization efficiencies were investigated in detail. This catalyst can be recovered easily and reused at least 7 times maintaining the catalytic activity. For different substrates, the efficiencies of sulfur removal decreased as the following orders: DBT > 4,6-DMDBT > BT under the same conditions. Finally, the mechanism of desulfurization was also elucidated.Download full-size image

•PW12/TiO2 nanofibers have been firstly prepared by combining electrospinning and calcination methods and show ultra-deep desulfurization catalytic performance in mild conditions.•DBT can be removed completely within 30 min at 70 °C using 0.02 g 40 wt.% PW12/TiO2 nanofibers as catalysts in extraction catalytic oxidation desulfurization system.•PW12/TiO2 nanofibers can be easily separated and recycled at least 5 times, and have the potential application of deep desulfurization in industry.H3PW12O40/TiO2 (abbreviated PW12/TiO2) nanofibers catalysts have been successfully prepared via calcinating off the respective electrospun PVP/[PW12 + Ti(OC4H9)4] composite nanofibers for the first time and they show ultra-deep desulfurization catalytic performance in mild conditions. PW12/TiO2 nanofibers consist of anatase phase TiO2 and Keggin structure PW12, the diameter of which is approximately 100 nm. Compared with PW12/TiO2 nanoparticles, 40 wt.% PW12/TiO2 nanofibers (the weight percentage of PW12 loading on TiO2 nanofibers was 40%) exhibited the higher catalytic activity under the same conditions. DBT could be removed completely within 30 min at 70 °C using 0.02 g 40 wt.% PW12/TiO2 nanofibers as catalysts, when ionic liquid (IL) [Bmim]PF6 was as extraction agent. Additionally, sulfur removal of different substrates decreased in the following orders: DBT > BT > 4,6-DMDBT under the same conditions. Even after 5-times recycling, the catalytic activity of 40 wt.% PW12/TiO2 nanofibers was not significant decreased. As a total result, these novel PW12/TiO2 nanofibers can be used to deeply desulfurize in the industry.Download high-res image (207KB)Download full-size imageNanofibers have attracted increasing interest among scientists owing to their anisotropy, large length-diameter ratio, and unique optical, electrical and magnetic properties. H3PW12O40/TiO2 (PW12/TiO2) nanofibers catalysts have been successfully prepared combining electrospinning technology and calcination methods for the first time and they show ultra-deep desulfurization catalytic performance in mild conditions. PW12 could be well dispersed on the TiO2 nanofibers, which improve the catalytic activity and recyclability of catalysts. When the weight percentage of PW12 loading on TiO2 nanofibers was 40% (40 wt.% PW12/TiO2 nanofibers), DBT removal efficiency reached 100% within 30 min under the optimal desulfurization conditions, which was more effective than that using 40 wt.% PW12/TiO2 nanoparticles as catalysts. After 5-times recycling, the catalytic activity of 40 wt.% PW12/TiO2 nanofibers was not significant decrease. Therefore, these novel PW12/TiO2 nanofibers can be used to deeply desulfurize in industry.

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.