Huanwang Jing

The mechanism of selective C–H cyanation of 2-phenylpyridine catalyzed by CuBr was investigated using the DFT method at the B3LYP/6-31+G(d,p) level, and the integral equation formalism polarized continuum model (IEFPCM) was applied to simulate the solvent effect. The computational results suggested that 2-phenylacetonitrile can convert into benzoyl cyanide under O2 conditions via two paths (a and b), and also, 2-phenylacetonitrile can first react with the O2− anion to yield 2-hydroxy-2-phenylacetonitrile, and then 2-hydroxy-2-phenylacetonitrile goes through oxidative dehydrogenation to yield benzoyl cyanide via four different paths (c, d, e and f). The other part reaction of the conversion of 2-phenylpyridine to 2-(pyridin-2-yl)-benzonitrile catalyzed by CuBr can go through three paths (g, h and i) which involve the coordination of CN− and the N atom of 2-phenylpyridine with Cu cations, and then the processes of addition and oxydehydrogenation reactions lead to the final product 2-(pyridin-2-yl)benzonitrile. In addition, another path (j) without the participation of CuBr could also occur. The results could provide valuable insights into these types of interactions and related ones.

Photoelectrocatalytic reduction of CO2 to methanol over the multi-functionalized TiO2 photocathodes

Co-reporter:Yanjie Xu, Yongjian Jia, Yuqian Zhang, Rong Nie, Zhenping Zhu, Jianguo Wang, Huanwang Jing

Applied Catalysis B: Environmental 2017 Volume 205(Volume 205) pp:

Publication Date(Web):15 May 2017

DOI:10.1016/j.apcatb.2016.12.039

•Multi-functionalized TiO2 photocathodes were established for CO2 reduction with Co-Pi/W:BiVO4 film as counter electrode.•In photocathode, Pd nanoparticles catch protons, dye absorbs solar energy, and amine ligands capture and activate CO2.•The Faradaic efficiency of PEC cell exceeds 1000% due to the synergistic effect of photo- and electro-catalytic process.The photoelectrocatalytic (PEC) reduction of CO2 to chemical fuels was achieved by utilizing the multi-functionalized TiO2 film photocathodes. On the surfaces of TiO2 films, Pd nanoparticles were introduced to catch protons, molecules of Eosin Y disodium salt were embedded to absorb solar energy, and four different amine ligands were immobilized to capture and activate CO2. In the novel PEC cells, multi-functionalized TiO2 and Co-Pi/W:BiVO4 films were served as photocathode and the counter electrode, respectively. It was found that methanol was the major liquid product. Besides, some ethanol and acetone can be detected as well. The maximum formation rate and the highest selectivity of methanol were 43.6 μM cm−2 h−1 and approximately 100%, respectively. The Faradaic efficiencies of the PEC cells can exceed 1000% with the aid of photoelectrons. The 13CO2 labeling experiments verify that methanol and carbon monoxide are derived from CO2.Download high-res image (182KB)Download full-size image

Mechanisms of Csp3-H functionalization of ethyl 2-(methyl(p-tolyl)amino)acetate: A theoretical investigation

Co-reporter:Da-Gang Zhou, Pan-Pan Zhou, Huan-Wang Jing

Computational and Theoretical Chemistry 2017 Volume 1118(Volume 1118) pp:

Publication Date(Web):15 October 2017

DOI:10.1016/j.comptc.2017.09.003

•The mechanisms for Csp3-H activation of ethyl 2-(methyl(p-tolyl)amino)acetate via four paths are proposed.•The dehydration process as the rate-determining step is paramount in the reaction.•Water plays a crucial role in the dehydration process.The mechanisms for the Csp3-H functionalization of ethyl 2-(methyl(p-tolyl)amino)acetate have been investigated using DFT method at the M06-2X/6-31+G(d, p) level, and the SMD model was applied to simulate the solvent effect. The computational results show that the Csp3-H functionalization has four possible paths to generate intermediate radical. Then addition reaction happens between the radical and O2 molecule. Finally, the addition product can convert into 1,5-dimethylindoline-2,3-dione via two different paths. The results could provide valuable insights into these types of interactions and related ones.Download high-res image (109KB)Download full-size image

Fe3O4@SiO2 supported aza-crown ether complex cation ionic liquids: preparation and applications in organic reactions

Co-reporter:Dandan Li;Jinyuan Wang;Fengjuan Chen

RSC Advances (2011-Present) 2017 vol. 7(Issue 8) pp:4237-4242

Publication Date(Web):2017/01/10

DOI:10.1039/C6RA25291E

A series of aza-crown ether ionic liquids supported on magnetic Fe3O4@SiO2 core–shell particles were designed, synthesized and characterized by elemental analysis, TEM, TG and FT-IR. These new aza-crown ether complex cation ionic liquids were utilized as heterogeneous acidic catalysts in Friedel–Crafts alkylation and Hantzsch reaction in good yields under convenient reaction conditions. Moreover, these magnetic particle supported IL catalysts could be readily recovered by an external magnet and reused five times without obvious loss of activity.

The role of a metallic copper interlayer during visible photocatalytic hydrogen generation over a Cu/Cu2O/Cu/TiO2 catalyst

Co-reporter:Wenlong Zhen;Wenjun Jiao;Yuqi Wu;Gongxuan Lu

Catalysis Science & Technology (2011-Present) 2017 vol. 7(Issue 21) pp:5028-5037

Publication Date(Web):2017/10/30

DOI:10.1039/C7CY01432E

The role of metallic copper as a co-catalyst is still uncertain, which is an interesting problem in photocatalytic hydrogen evolution. There is debate over the role of Cu+, Cu2+ and metallic Cu during photocatalytic hydrogen generation. Herein, we identified that the metallic copper interlayer between Cu2O and TiO2 played a key role in the hydrogen evolution process. By fabricating the metallic Cu interlayer via in situ reduction of Cu2O/TiO2, efficient charge transfer took place over the Cu/Cu2O/Cu/TiO2 catalyst, while a retarded electron transfer was found over the Cu/TiO2 catalyst. This interlayer structure provides a bridge for photoelectron transfer from th`e conduction band of TiO2 to Cu2O, significantly prolonging the life-time of electron transfer. In addition, the ratio of metallic Cu and Cu2O could be easily adjusted by the loading amount of Cu2O on TiO2, and that the ratio affects the photocatalytic hydrogen evolution activity. A high transient photocurrent and long fluorescence lifetime (0.365 ns) were achieved over the Cu/Cu2O/Cu/TiO2 catalyst when the molar ratio of the interlayer metallic Cu to Cu2O was 0.99. Under the same reaction conditions, the photocatalytic hydrogen generation activity of the Cu/Cu2O/Cu/TiO2 catalyst was three times than that observed with the Cu/TiO2 catalyst with good stability.

The role of a metallic copper interlayer during visible photocatalytic hydrogen generation over a Cu/Cu2O/Cu/TiO2 catalyst

Co-reporter:Wenlong Zhen;Wenjun Jiao;Yuqi Wu;Gongxuan Lu

Catalysis Science & Technology (2011-Present) 2017 vol. 7(Issue 21) pp:5028-5037

Publication Date(Web):2017/10/30

DOI:10.1039/C7CY01432E

Reply to the ‘Comment’ on “Lewis acidic ionic liquids of crown ether complex cations: preparation and applications in organic reactions” by M. Swadźba-Kwaśny, RSC Adv., 2017, 7, DOI: 10.1039/c7ra05921c

Co-reporter:Jinyuan Wang;Panpan Zhou

RSC Advances (2011-Present) 2017 vol. 7(Issue 85) pp:53686-53688

Publication Date(Web):2017/11/21

DOI:10.1039/C7RA09037D

No abstract available

Artificial photosynthesis of methanol from carbon dioxide and water via a Nile red-embedded TiO2 photocathode

Co-reporter:Yongjian Jia;Yanjie Xu;Rong Nie;Fengjuan Chen;Zhenping Zhu;Jianguo Wang

Journal of Materials Chemistry A 2017 vol. 5(Issue 11) pp:5495-5501

Publication Date(Web):2017/03/14

DOI:10.1039/C6TA10231J

The conversion of carbon dioxide into useful chemicals is a prospective strategy for alleviating the greenhouse effect and the depletion of energy. Herein, we report an artificial photosynthetic system composed of a photoanode and a photocathode comprised of NRx@TiO2 functionalized with Nile red via covalent linkage or Pd/NRx@TiO2 with additional palladium nanoparticles. The new Nile red derivatives and organic–inorganic composite electrodes were steadily prepared and well characterized using NMR, HRMS, UV-vis, FTIR, TEM, XPS, XRD and SEM. Methanol and oxygen were the products that could be detected in the liquid and gas phase. The main active species in this artificial photosynthesis system were proven using EPR spectroscopy to be hydroxy radicals releasing O2 gas via H2O2. Moreover, the carbon source of methanol was validated using a 13CO2 labeling experiment; 18O2 was determined to come from H2O using GC-MS. The optimal photoelectrocatalytic CO2 reduction was carried out using Pd/NR2@TiO2 as the working electrode yielding methanol at a rate of 106 μM h−1 cm−2 with high light quantum efficiency (Φcell = 0.95).

Cycloaddition of epoxides and CO2 catalyzed by bisimidazole-functionalized porphyrin cobalt(III) complexes

Co-reporter:Xu Jiang, Faliang Gou, Fengjuan Chen and Huanwang Jing

Green Chemistry 2016 vol. 18(Issue 12) pp:3567-3576

Publication Date(Web):09 Mar 2016

DOI:10.1039/C6GC00370B

A series of innovative bisimidazole-functionalized porphyrin cobalt(III) complexes have been devised, synthesized and characterized using NMR, MS and elemental analysis. These homogeneous catalysts were applied to the cycloaddition of epoxides and carbon dioxide without organic solvent and co-catalyst. It was found that the performance of the catalysts deeply relies on their structural features. The alkoxyl chain length of the linkage and the imidazole position relative to the phenyl rings of porphyrin evidently affects the catalyst activities. [5,15-Di(3-((8-imidazolyloctyl)oxy)phenyl)porphyrin] cobalt(III) chloride (J-m8) and [5,15-di(2-((6-imidazolylhexyl)oxy)phenyl)porphyrin] cobalt(III) chloride (J-o6) demonstrated excellent activity under optimal reaction conditions. Synchronously, a preliminary kinetic investigation of this reaction was carried out using three catalysts and illustrated the activation energies of cyclic carbonate formation. Furthermore, a tri-synergistic catalytic mechanism has been carefully proposed in light of the features of the new catalysts and experimental results.

Palladium-Catalyzed Intramolecular Dearomatization of Indoles via Decarboxylative Alkynyl Termination

Co-reporter:Si Chen, Xin-Xing Wu, Jia Wang, Xin-Hua Hao, Yu Xia, Yi Shen, Huanwang Jing, and Yong-Min Liang

Organic Letters 2016 Volume 18(Issue 16) pp:4016-4019

Publication Date(Web):August 10, 2016

DOI:10.1021/acs.orglett.6b01711

A highly diastereoselective dearomatization of indoles via palladium-catalyzed decarboxylative alkynyl termination was developed. This protocol provides dissimilar tetracyclic and tetrasubstituted indoline scaffolds bearing congested stereocenters, which led to operationally simple conditions, short time, and broad substrate scope. Additionally, this reaction system could be scaled to gram quantities in a satisfactory yield and diastereoselectivity.

π-Spacer effect in dithiafulvenyl-π-phenothiazine dyes for dye-sensitized solar cells

Co-reporter:Xiaofeng Zhang, Faliang Gou, Dongning Zhao, Jian Shi, Hong Gao, Zhenping Zhu, Huanwang Jing

Journal of Power Sources 2016 Volume 324() pp:484-491

Publication Date(Web):30 August 2016

DOI:10.1016/j.jpowsour.2016.05.120

•Four new dithiafulvenyl-π-phenothiazine dyes have been synthesized for DSSCs.•The inserted π-spacers markedly enhance charge separation in DPP series dyes.•The torsion structures of D-π-D-A dyes suppress their aggregation on TiO2 surface.•DPP-4 sensitized solar cells achieve the best efficiency of 7.66%.New dithiafulvenyl-π-phenothiazine dyes have been devised and prepared for dye-sensitized solar cells. Various π-spacers have been successfully introduced into the skeleton of dithiafulvenyl and phenothiazine unit to generate novel D-π-D-A dyes (DPP-1 ∼ 4). All dyes have been characterized with NMR, HRMS, UV–vis and fluorescence spectra, and taken into cyclic voltammetry measurements. The devices of new dyes have been determined by photoelectrochemical experiments (IV, IPCE and EIS), in which, solar cell of DPP-4 with biphenyl ring π-spacer enhances obviously its photoelectric conversion efficiency to 7.66% reaching 94% of N719-based standard cell and displays good long-term stability with quasi-solid-state electrolyte. Density functional theory (DFT) calculations of new dyes provide further insight into the molecular geometries and the impacts of the torsion angles on their photovoltaic performance. Large dihedral angles in DPP dyes induce good charge separation for efficient unidirectional flow of electron from donor to acceptor.

Mechanisms of cascade reactions between N-methylindole and sulfonylazides via Huisgen cycloaddition: A theoretical investigation

Co-reporter:Da-Gang Zhou, Pan-Pan Zhou, Huan-Wang Jing

Journal of Molecular Catalysis A: Chemical 2016 Volume 417() pp:19-27

Publication Date(Web):June 2016

DOI:10.1016/j.molcata.2016.03.010

•The mechanisms for cascade reactions between N-methylindole and sulfonylazides via Huisgen cycloaddition were proposed.•Two possible reaction pathways I and II were found for these Huisgen cycloaddition reactions.•The gaseous environment and solvent play crucial roles in determining the product.The mechanisms of three cascade reactions between N-methylindole and sulfonylazides via Huisgen cycloaddition were investigated using density functional theory, and the polarized continuum model (PCM) was applied to simulate the solvent effects. Fukui functions and dual descriptor have been employed to assess the atomic reactivity. With respect to these three reactions, each has two possible reaction pathways (I and II). The calculated results show that singlet O2 plays a crucial role in the oxidative dehydrogenation process in the first reaction between 2-imine indole and p-tosylazide (TsN3), when the reaction occurs without O2 but with N2, two pathways via the processes of breaking two covalent bonds, followed by 1,2-H shift and N2 removal (or by N2 removal and 1,2-H shift) exist. Water molecule plays an important role in the H-shift process in the third reaction of the methyl substituted N-methylindole with TsN3. Our results demonstrated that these reactions can take place at certain condition, in good agreement with the experimental observation. The understanding of the competitive pathways for Huisgen cycloaddition of N-methylindole and sulfonylazides can provide valuable insights into related reactions.

Catalytic asymmetric cycloaddition of CO2 to epoxides via chiral bifunctional ionic liquids

Co-reporter:Shuhui Duan, Xinyao Jing, Dandan Li, Huanwang Jing

Journal of Molecular Catalysis A: Chemical 2016 Volume 411() pp:34-39

Publication Date(Web):January 2016

DOI:10.1016/j.molcata.2015.10.008

•A series of new chiral bifunctional ionic liquid catalysts incorporating the N,N′-bis(salicyclidene)cyclohexene diaminatocobalt and an imidazolium salt in one molecule were designed and synthesized.•A kinetic resolution of racemic epoxides with carbon dioxide to generate chiral cyclic carbonates was achieved in high yield with reasonable enantioselectivity.•The effects of anixal anion, counterions and the chain length of alkyl of catalysts in these asymmetric cycloadditions were discussed.A series of new chiral ionic liquid catalysts composed of the N,N'-bis(salicyclidene) cyclohexene diaminatocobalt and an imidazolium salt were designed, prepared and applied for the chiral cyclic carbonate synthesis from racemic epoxides and carbon dioxide. All reactions exhibit good enantioselectivity for the chiral cyclic carbonate without polycarbonate and other by-products. The order of The order of catalytic activity toward the axial anions is OAc− > CF3CO2− > CCl3CO2− > OTs− and the order of enantioselectivity is OTs− > OAc− > CCl3CO2− > CF3CO2−.

Mechanisms of water-promoted aryl azide conversion into N-alkylated aniline: Two competitive pathways

Co-reporter:Da-Gang Zhou, Pan-Pan Zhou, Huan-Wang Jing

Computational and Theoretical Chemistry 2015 1070() pp: 76-81

Publication Date(Web):15 October 2015

DOI:10.1016/j.comptc.2015.07.026

•The mechanism for the conversion of aryl azide into N-alkylated aniline is proposed.•The alkylating agent Bu2BOTf acts as an electrophilic agent.•Water plays a crucial role in the hydrolytic process.The reaction mechanism for the conversion of aryl azide into N-alkylated aniline using Bu2BOTf as an alkylating agent has been unveiled by employing density functional theory (DFT) calculations at the B3LYP/6-31+G(d,p) level of theory and the reactivity indices like Fukui function and dual descriptor. The results show that the electrophilic attack of Bu2BOTf on aryl azide leads to the abscission of N2 via SN2 reaction, then the obtained intermediate goes through a critical step of hydrolytic procedure to generate the product. Water molecule play a crucial role in obtaining the product, the hydrolytic process can probably proceed via two competitive pathways I and II in which one and two water molecules are involved, respectively. Pathway II with CH2Cl2 as solvent is more favorable, which could be the actual reaction process to yield the product. The energy profile for the whole reaction indicates that it can be realized at room temperature, consistent with the experimental results.

Strategy to Improve Photovoltaic Performance of DSSC Sensitized by Zinc Prophyrin Using Salicylic Acid as a Tridentate Anchoring Group

Co-reporter:Faliang Gou, Xu Jiang, Ran Fang, Huanwang Jing, and Zhenping Zhu

ACS Applied Materials & Interfaces 2014 Volume 6(Issue 9) pp:6697

Publication Date(Web):April 24, 2014

DOI:10.1021/am500391w

Three new zinc porphyrin dyes attached to ethynyl benzoic acid as an electron transmission and anchoring group have been designed, synthesized, and well-characterized. The performances of their sensitized solar cells have been investigated by optical, photovoltaic, and electrochemical methods. The photoelectric conversion efficiency of the solar cells sensitized by the dye with salicylic acid as an anchoring group demonstrated obvious enhancement when compared with that sensitized by the dye with carboxylic acid as an anchoring group. The density functional theory calculations and the electrochemical impedance spectroscopies revealed that tridentate binding modes could increase the efficiency of electron injection from dyes to the TiO2 nanoparticles by more electron pathways.Keywords: anchoring group; dye-sensitized solar cell; salicylic acid; zinc porphyrin dye;

New magnetic nanocomposites of ZrO2–Al2O3–Fe3O4 as green solid acid catalysts in organic reactions

Co-reporter:Anqi Wang, Xiang Liu, Zhongxing Su and Huanwang Jing

Catalysis Science & Technology 2014 vol. 4(Issue 1) pp:71-80

Publication Date(Web):25 Sep 2013

DOI:10.1039/C3CY00572K

A series of magnetic solid acid nano-catalysts were designed and prepared through a facile co-precipitate approach. The original nanocomposites ZrO2–Al2O3–Fe3O4 were characterized by means of ICP-AES, BET, XRD, TEM, HRTEM, VSM, FT-IR, NH3-TPD and TG. Their catalytic behaviours were investigated via esterification, the synthesis of bis-indolylmethanes, Hantzsch reaction, Biginelli reaction and Pechmann reaction. In all of these organic reactions, the corresponding products were obtained in moderate to excellent yields. The optimal catalyst was ZAF-16/16, which retained catalytic activity after several recycles.

Brønsted acidic ionic liquids of aza-crown ether complex cations: preparation and applications in organic reactions

Co-reporter:Chen Cheng and Huanwang Jing

RSC Advances 2014 vol. 4(Issue 65) pp:34325-34331

Publication Date(Web):25 Jul 2014

DOI:10.1039/C4RA03061C

A series of novel Brønsted acidic ionic liquids composed of an aza-crown ether chelated potassium cation and various anions, were designed, synthesized and characterised by FTIR, NMR and mass spectrometry, thermogravimetric differential thermal analysis (TG-DTA) and elemental analysis. These new Brønsted acidic ionic liquids of aza-crown ether complex cations (aCBAILs) were applied as catalysts to the Biginelli reaction, Mannich reaction and synthesis of bis-(4-hydroxycoumarin-3-yl)methanes. These organic reactions were achieved in good yields under mild reaction conditions. Moreover, these new IL catalysts can be recycled several times.

Combined use of [TBA][L-ASP] and hydroxypropyl-β-cyclodextrin as selectors for separation of Cinchona alkaloids by capillary electrophoresis

Co-reporter:Yu Zhang, Haixia Yu, Yujiao Wu, Wenyan Zhao, Min Yang, Huanwang Jing, Anjia Chen

Analytical Biochemistry 2014 Volume 462() pp:13-18

Publication Date(Web):1 October 2014

DOI:10.1016/j.ab.2014.06.008

Abstract

In this paper, a new capillary electrophoresis (CE) separation and detection method was developed for the chiral separation of the four major Cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine) using hydroxypropyl-β-cyclodextrin (HP-β-CD) and chiral ionic liquid ([TBA][L-ASP]) as selectors. Separation parameters such as buffer concentrations, pH, HP-β-CD and chiral ionic liquid concentrations, capillary temperature, and separation voltage were investigated. After optimization of separation conditions, baseline separation of the three analytes (cinchonidine, quinine, cinchonine) was achieved in fewer than 7 min in ammonium acetate background electrolyte (pH 5.0) with the addition of HP-β-CD in a concentration of 40 mM and [TBA][L-ASP] of 14 mM, while the baseline separation of cinchonine and quinidine was not obtained. Therefore, the first-order derivative electropherogram was applied for resolving overlapping peaks. Regression equations revealed a good linear relationship between peak areas in first-order derivative electropherograms and concentrations of the two diastereomer pairs. The results not only indicated that the first-order derivative electropherogram was effective in determination of a low content component and of those not fully separated from adjacent ones, but also showed that the ionic liquid appeared to be a very promising chiral selector in CE.

SalenZn-bridged D--A Dyes For Dye-Sensitized Solar Cells

Co-reporter:Yongjian Jia;Faliang Gou;Ran Fang;Zhenping Zhu

Chinese Journal of Chemistry 2014 Volume 32( Issue 6) pp:513-520

Publication Date(Web):

DOI:10.1002/cjoc.201300924

Abstract

A series of SalenZn based dyes with triphenylamine derivatives as the donor, benzoic acid as the acceptor, and coplanar Salen complexes as the spacer have been designed and synthesized for dye-sensitized solar cells. The absorption, electrochemical, and photovoltaic properties for all sensitizers have been systematically investigated. When the tail length of the alkyl substituents is increased from C-0 to C-8 on the donor part, the efficiency of its DSSC augments evidently. It is found that the incorporation of bis-carboxyl groups instead of the single carboxyl group as anchoring groups induces a remarkable enhancement of the electron injection efficiency from the excited dyes to the TiO₂ semiconductor and generates higher electron density and voltage.

Aza-Crown Ether Complex Cation Ionic Liquids: Preparation and Applications in Organic Reactions

Co-reporter:Dr. Yingying Song;Chen Cheng ; Huanwang Jing

Chemistry - A European Journal 2014 Volume 20( Issue 40) pp:12894-12900

Publication Date(Web):

DOI:10.1002/chem.201403118

Abstract

Aza-crown ether complex cation ionic liquids (aCECILs) were devised, fabricated, and characterized by using NMR spectroscopy, MS, thermogravimetric differential thermal analysis (TG-DTA), elemental analysis and physical properties. These new and room-temperature ILs were utilized as catalysts in various organic reactions, such as the cycloaddition reaction of CO₂ to epoxides, esterification of acetic acid and alcohols, the condensation reaction of aniline and propylene carbonate, and Friedel–Crafts alkylation of indole with aldehydes were investigated carefully. In these reactions, the ionic liquid exhibited cooperative catalytic activity between the anion and cation. In addition, the aza-[18-C-6HK][HSO₄]₂ was the best acidic catalyst in the reactions of esterification and Friedel–Crafts alkylation under mild reaction conditions.

Chiral separation and determination of amino acids in real samples by LE-MEKC using Cu(II)-l-proline as chiral selector

Co-reporter:Yujiao Wu, Yuyao Zhai, Yu Zhang, Hongfen Zhang, Huanwang Jing, Anjia Chen

Journal of Chromatography B 2014 Volume 965() pp:254-259

Publication Date(Web):15 August 2014

DOI:10.1016/j.jchromb.2014.07.001

•We evaluated various kinds of real samples.•We measured the physical constant (CMC, see in Fig. 2) by CE.•The method has a great influence on the clinical auxiliary diagnosis of diabetes.•We discussed the mechanism of this method in details.This work reports that Cu(II) complexes with l-proline were used as chiral additives for the enantioseparations and determination of three underivatized amino acids by ligand-exchange micellar electrokinetic chromatography (LE-MEKC). Sodium dodecylsulfate (SDS) was shown to be necessary for simultaneous separation of the enantiomeric amino acids. Separation parameters such as SDS concentrations, the Cu(II)-l-proline ratio, the concentration of the copper(II) complex at a specific Cu(II)-l-proline ratio, pH and separation voltage were investigated for the enantioseparation in order to achieve the maximum possible resolution. A good separation was achieved in the BGE composing of 10 mM ammonium acetate, 10 mM Cu(II) and 20 mM l-proline and 30 mM SDS at pH 5.0, and an applied voltage of 15 kV performed. Under above-mentioned optimum conditions, linearity was achieved within concentration ranges of up to two orders of magnitudes for the investigated amino acids with the correlation coefficients ranging from 0.9917 to 0.9984. The proposed method has been successfully applied to the determination of amino acid enantiomers in human urine, compound amino acids injection, and amino acid oral liquid.

Salicylic Acid As a Tridentate Anchoring Group for azo-Bridged Zinc Porphyrin in Dye-Sensitized Solar Cells

Co-reporter:Faliang Gou, Xu Jiang, Bo Li, Huanwang Jing, and Zhenping Zhu

ACS Applied Materials & Interfaces 2013 Volume 5(Issue 23) pp:12631

Publication Date(Web):November 14, 2013

DOI:10.1021/am403987b

Two series dyes of azo-bridged zinc porphyrins have been devised, synthesized, and performed in dye-sensitized solar cells, in which salicylic acids and azo groups were introduced as a new anchoring group and π-conjugated bridge via a simple synthetic procedure. The representation of the new dyes has been investigated by optical, photovoltaic, and electrochemical means. The photoelectric conversion efficiency of their DSSC devices has been improved compared with other DSSC devices sensitized by symmetrical porphyrin dyes. The results revealed that tridentate binding modes between salicylic acid and TiO2 nanoparticles could enhance the efficiency of electron injection. The binding modes between salicylic acid and TiO2 nanoparticles may play a crucial role in the photovoltaic performance of DSSCs.Keywords: anchoring group; azo-bridge; dye-sensitized solar cells; porphyrin dye; salicylic acid;

Photovoltaic performance enhancement of dye-sensitized solar cells by formation of blocking layers via molecular electrostatic effect

Co-reporter:Bo Li, Jiazang Chen, Jianfeng Zheng, Jianghong Zhao, Zhenping Zhu, Huanwang Jing

Electrochimica Acta 2012 Volume 59() pp:207-212

Publication Date(Web):1 January 2012

DOI:10.1016/j.electacta.2011.10.056

The improvement in photovoltaic performance of dye-sensitized solar cells was found after aging in the dark and was analyzed by linear sweep voltammetry and electrochemical impedance spectroscopy. The promotion was found to arise from the formation of blocking layers on the surface of nanocrystalline TiO2, resulting most likely from the intermolecular electrostatic action between the 4-tert-butylpyridine and the 1,2-dimethyl-3-propylimidazolium ions. These blocking layers can retard the interfacial reaction of the electron with I3− ions without deteriorating the rate of regeneration of the oxidized dye molecules. By virtue of the blocking layers, the retarding recombination of electrons with the I3− ions significantly increased the electron lifetime and enlarged the electron diffusion length, resulting in a higher open-circuit voltage and an improvement in charge collection efficiency, and eventually an enhancement of the energy conversion efficiency.

Brønsted acid improved cycloaddition of carbon dioxide to propylene oxide

Co-reporter:Bo Li, Lilong Zhang, Yingying Song, Dongsheng Bai, Huanwang Jing

Journal of Molecular Catalysis A: Chemical 2012 Volumes 363–364() pp:26-30

Publication Date(Web):November 2012

DOI:10.1016/j.molcata.2012.05.012

New and highly efficient catalyst systems of 5,10,15,20-tetra(4-carboxyphenyl)porphyrinato cobalt salt (TCPPCo(III)X/PTAT, X = CF3COO, OAc, Br, Cl) were developed to catalyze the coupling reaction of carbon dioxide and propylene oxide. It was discovered that the Brønsted acid can accelerate this reaction. A kinetic study demonstrated that the coupling reaction follows the rule of first order reaction and the reaction with addition of organic acid has lower activation energy than that without organic acid. This promotion can be attributed to the additional activation of epoxides by hydrogen bonding.Graphical abstractHighlights► TCPPCo(III)CF3COO/PTAT was effective for the reaction of propylene oxide and CO2. ► Brønsted acids were found to have promotion on this coupling reaction. ► A kinetic study was carried out to further reveal this coupling reaction. ► A reasonable reaction mechanism was proposed.

One Approach to Cyclic Carbonates via a Three-Component Cyclization of Phenacyl Bromide, CO2, and Aldehyde

Co-reporter:Peng Yan, Xueqin Tan, Huanwang Jing, Shuhui Duan, Xiaoxuan Wang, and Zhongli Liu

The Journal of Organic Chemistry 2011 Volume 76(Issue 8) pp:2459-2464

Publication Date(Web):March 14, 2011

DOI:10.1021/jo1020294

A three-component cyclization reaction was designed for synthesizing cyclic carbonates in a single operation from phenacyl bromide, CO2, and aldehyde in the presence of lithium diisopropylamide (LDA). These novel reactions were achieved under extremely mild conditions to generate the target products in moderate to good yields within 10 min.

Crown Ether Complex Cation Ionic Liquids: Preparation and Applications in Organic Reactions

Co-reporter:Dr. Yingying Song; Huanwang Jing;Dr. Bo Li ;Dr. Dongsheng Bai

Chemistry - A European Journal 2011 Volume 17( Issue 31) pp:8731-8738

Publication Date(Web):

DOI:10.1002/chem.201100112

Abstract

A series of crown ether complex cation ionic liquids (CECILs) were designed, synthesised and characterised by NMR spectroscopy, HRMS, thermogravimetric differential thermal analysis (TG-DTA) and elemental analysis. Their applications in various organic reactions were investigated: [15-C-5Na][OH], [15-C-5Na][OAc], [18-C-6K][OH] and [18-C-6K][OAc] (15-C-5=[15]crown-5; 18-C-6=[18]crown-6) efficiently catalysed the Michael addition of alkenes and relevant nucleophiles; [18-C-6K][OH] and [15-C-5Na][OH] effectively catalysed the Henry reaction of nitromethane and aromatic aldehydes; [18-C-6K][OH] has excellent catalytic efficiency for Knoevenagel condensation of aromatic aldehydes and malononitrile; PdCl₂/[18-C-6K]₃[PO₄]/K₂CO₃ efficaciously catalysed the Heck reaction of olefins and aromatic halides; [18-C-6K][BrO₃] can be used as both oxidant and solvent in the oxidation reaction of aromatic alcohols. The CECIL catalysts [15-C-5Na][OH] (Michael addition) and [18-C-6K][OH] (Henry reaction) can be recycled and reused several times without obvious loss of activity and their recovery is very simple.

Chiral metal-containing ionic liquid: Synthesis and applications in the enantioselective cycloaddition of carbon dioxide to epoxides

Co-reporter:YingYing Song;QianRu Jin;SuLing Zhang

Science China Chemistry 2011 Volume 54( Issue 7) pp:1044-1050

Publication Date(Web):2011 July

DOI:10.1007/s11426-011-4274-2

A series of novel chiral metal-containing ionic liquids (CMILs) consisting of the cation of crown ether-chelated potassium/sodium and the anion of chiral amino acids were designed and synthesized. These new CMILs were used to catalyze the enantioselective cycloaddition of epoxides and carbon dioxide incorporating with the salenCo(OOCCCl3) to generate corresponding chiral cyclic carbonates under mild conditions. These new catalysts can be recycled at least five times without significant loss of activity and enantioselectivity.

Aerobic oxidative carboxylation of olefins with metalloporphyrin catalysts

Co-reporter:Dongsheng Bai and Huanwang Jing

Green Chemistry 2010 vol. 12(Issue 1) pp:39-41

Publication Date(Web):27 Oct 2009

DOI:10.1039/B916042F

Dioxo(tetraphenylporphyrinato)ruthenium(VI) and quaternary onium salt were successfully developed as catalysts to initiate a three component reaction of olefin, O2, and CO2 at ambient temperature under low pressure. The reaction can be carried out under solvent-free or solvent conditions. Styrene carbonate was obtained in 76% yield with 100% selectivity using 4 mol% of catalyst under optimized conditions.

Chiral ionic liquids improved the asymmetric cycloaddition of CO2 to epoxides

Co-reporter:Suling Zhang, Yongzhong Huang, Huanwang Jing, Weixuan Yao and Peng Yan

Green Chemistry 2009 vol. 11(Issue 7) pp:935-938

Publication Date(Web):14 Apr 2009

DOI:10.1039/B821513H

The new catalyst system of chiral SalenCo(OAc)/chiral ionic liquid was developed to catalyze the asymmetric cycloaddition reaction of CO2 and epoxides yielding the chiral cyclic carbonates. The synergistic effect between them is discussed.

Bifunctional Chiral Catalyst for the Synthesis of Chiral Cyclic Carbonates from Carbon Dioxide and Epoxides

Co-reporter:Tao Chang;Lili Jin

ChemCatChem 2009 Volume 1( Issue 3) pp:379-383

Publication Date(Web):

DOI:10.1002/cctc.200900135

Abstract

Bifunctional chiral catalysts incorporating the N,N′-bis(salicylidene)cyclohexenediaminato (salen) ligand and a quaternary onium salt within one metal complex were synthesized and developed for the catalytic kinetic resolution of racemic epoxides with carbon dioxide to generate chiral cyclic carbonates in high yield and with moderate enantioselectivity. These new catalysts also have a great advantage as they can be recycled without any obvious loss of activity and enantioselectivity.

Synthesis, crystal structure, and magnetic properties of 1D Azido-bridged copper(II) complex

Co-reporter:Guoqi Liu;Desheng Xue

Structural Chemistry 2008 Volume 19( Issue 1) pp:81-86

Publication Date(Web):2008 February

DOI:10.1007/s11224-007-9254-y

A novel copper(II)-azide complex of [Cu2(DMAP)2(μ-1,1-N3)2(μ-1,3-N3)2]n (DMAP = 4-(dimethylamino)pyridine) has been synthesized and characterized by IR spectra, X-ray diffraction, elemental analysis, and magnetism measurement. The complex reveals a 1D ladder-like chain structure, in which two μ-1,1-N3 and two μ-1,3-N3 bridges form a dimeric unit of [Cu2(DMAP)2(μ-1,1-N3)2(μ-1,3-N3)2] and are then connected to each other from the tail nitrogens of two asymmetric μ-1,3-N3 bridges to generate a chain structure that stacks in the cell to construct the 3D crystal. The Cu atom is five-coordinated by azide anions to form a distorted square-pyramid of CuN5 (τ = 0.2667). Magnetic susceptibility of complex exhibits a ferromagnetic interaction between the copper(II) ions through two kinds of azido-bridges.

Chiral catalysts for the asymmetric cycloaddition of carbon dioxide with epoxides

Co-reporter:Lili Jin, Yongzhong Huang, Huanwang Jing, Tao Chang, Peng Yan

Tetrahedron: Asymmetry 2008 Volume 19(Issue 16) pp:1947-1953

Publication Date(Web):22 August 2008

DOI:10.1016/j.tetasy.2008.08.001

Several chiral BINADCo(III)X (BINAD = Bis(1,1′-2-hydroxy-2′-alkoxy-3-naphthylidene)-1,2-cyclohexanediamine, X = OAc, CF3CO2, CCl3CO2, OTs, p-NO2PhCO2) complexes were synthesized and used to catalyze the asymmetric cycloaddition of carbon dioxide with epoxides under mild condition to afford chiral cyclic carbonates. The best catalyst of (S,S,S,S)-BINADCo(III)(OAc) 9b and phenyltrimethylammonium tribromide (PTAT) can provide propylene carbonate with the highest ee being 95% at −20 °C.New catalysts of BINADCo(III)X were synthesized and applied to the asymmetric cycloaddition of CO2 with epoxides to generate chiral cyclic carbonates with moderate to excellent yield under very mild conditions.(1R,2R)-(−)-N,N′-Bis((R)-1,1′-2-hydroxy-2′-butoxy-3-naphthylidene))-1,2-cyclohexanediamineC56H54N2O4[α]D20=-88 (c 1.0, CH2Cl2)Source of chirality: (1R,2R)-cyclohexanediamine, (R)-BINOLAbsolute configuration: (R,R,R,R)(1S,2S)-(−)-N,N′-Bis((S)-1,1′-2-hydroxy-2′-butoxy-3-naphthylidene))-1,2-cyclohexanediamineC56H54N2O4[α]D20=+88 (c 1.0, CH2Cl2)Source of chirality: (1S,2S)-cyclohexanediamine, (S)-BINOLAbsolute configuration: (S,S,S,S)(1R,2R)-(−)-N,N′-Bis((R)-1,1′-2-hydroxy-2′-benzyloxy-3-naphthylidene))-1,2-cyclohexanediamineC62H50N2O4[α]D20=-108 (c 1.0, CH2Cl2)Source of chirality: (1R,2R)-cyclohexanediamine, (R)-BINOLAbsolute configuration: (R,R,R,R)(1R,2R)-(−)-N,N′-Bis((R)-1,1′-2-hydroxy-2′-phenyl-3-naphthylidene))-1,2-cyclohexanediamineC60H46N2O2[α]D20=-85 (c 1.0, CH2Cl2)Source of chirality: (1R,2R)-cyclohexanediamine, (R)-BINOLAbsolute configuration: (R,R,R,R)Bis((1R,2R)-(−)-N,N′-(R)-1,1′-bi-2-hydroxy-3-naphthylidene)-1,2-cyclohexanediamineC56H48N4O4[α]D20=-184 (c 0.5, CH2Cl2)Source of chirality: (1R,2R)-cyclohexanediamine, (R)-BINOLAbsolute configuration: (R,R,R,R)Bis((1R,2R)-(−)-N,N′-(S)-1,1′-bi-2-hydroxy-3-naphthylidene)-1,2-cyclohexanediamineC56H48N4O4[α]D20=-558 (c 0.5, CH2Cl2)Source of chirality: (1R,2R)-cyclohexanediamine, (S)-BINOLAbsolute configuration: (S,R,R,S)(1S,2S)-(−)-N,N′-Bis((R)-1,1′-2-hydroxy-2′-phenyl-3-naphthylidene))-1,2-cyclohexanediamineC60H46N2O2[α]D20=+197 (c 0.2, CH2Cl2)Source of chirality: (1S,2S)-cyclohexanediamine, (R)-BINOLAbsolute configuration: (R,S,S,R)

Ni-foam-supported and amine-functionalized TiO2 photocathode improved photoelectrocatalytic reduction of CO2 to methanol

Co-reporter:Liwen Wang, Yongjian Jia, Rong Nie, Yuqian Zhang, Fengjuan Chen, Zhenping Zhu, Jianguo Wang, Huanwang Jing

Journal of Catalysis (May 2017) Volume 349() pp:1-7

Publication Date(Web):1 May 2017

DOI:10.1016/j.jcat.2017.01.013

•New Ni-foam-supported and amine-functionalized TiO2 photocathodes were developed.•Energy band shifting is proved and attributed to organic ligand modification.•The light quantum efficiency reaches 1.2%, which is 2 times better than for plants.•Isotropic labeling and photoelectrochemical experiments prove the carbon source.We report new insights into the photoelectrochemical reduction of CO2 in a photoelectrochemical system, which is assembled from a nickel foam covered with TiO2 modified by covalent ligands as photocathode and BiVO4 as photoanode. These photoelectrocatalytic cells generate mainly methanol as a product in the liquid phase. Our results show that imine-functionalized TiO2/Ni has the highest activity. The formation rate of methanol in this excellent cell is up to 153 μM/h · cm2, which is about 15 times higher than that of the TiO2/Ni electrode. If the Faradaic efficiency is considered as 100%, the light quantum efficiency of this cell reaches 1.2%, that is two times better than that of plants. Isotopic labeling experiments with 13CO2 confirm that the detected products are produced exclusively by the reduction of CO2 and water splitting.Download high-res image (69KB)Download full-size image

Alternating copolymerization of CO2 and propylene oxide catalyzed by C2v-porphyrin cobalt: Selectivity control and a kinetic study

Co-reporter:Xu Jiang, Faliang Gou, Huanwang Jing

Journal of Catalysis (May 2014) Volume 313() pp:159-167

Publication Date(Web):1 May 2014

DOI:10.1016/j.jcat.2014.03.008

•New and efficient C2v-porphyrin cobalt catalysts were designed and synthesized for the PO/CO2 copolymerization.•Catalysts demonstrated excellent reactivity and selectively.•Detailed macro-kinetic investigations were carried out by two catalyst systems.•A competition mechanism was firstly proposed.Some C2v (Cs)-porphyrin cobalt complexes have been devised, synthesized and utilized as efficient catalysts in combination with dimethylaminopyridine for the alternating copolymerization of propylene oxide and carbon dioxide. The C2v-catalyst [5,15-diphenylporphyrin]cobalt(III) chloride (1d) has demonstrated excellent reactivity and selectivity under optimized conditions. The axial counterions and the substituents of these metalloporphyrins exhibited distinct infection on the catalytic activity and selectivity. Synchronously, preliminary kinetic investigations of this reaction were achieved by using two catalyst systems illustrating the activation energies of copolymerization and coupling reaction, respectively. A competition mechanism between the polymerization and cycloaddition of propylene oxide and CO2 has been carefully proposed according to our experimental results.Download high-res image (118KB)Download full-size image

Pd/C as a high efficient and reusable catalyst for cycloaddition of CO2 to epoxides

Co-reporter:Xiying Fu, Dagang Zhou, Kai Wang, Huanwang Jing

Journal of CO2 Utilization (June 2016) Volume 14() pp:31-36

Publication Date(Web):1 June 2016

DOI:10.1016/j.jcou.2016.02.003

•Pd/C was found to synthesize cyclic carbonate in good yield and high selectivity.•The cycloaddition of epoxide and CO2 can take place under extremely mild conditions.•Pd/C could be simply reused for 5 times without significant loss of activity.Pd/C was found to be an excellent catalyst in the coupling reaction of carbon dioxide and epoxides with tetrabutylammonium iodide (TBAI) as cocatalyst and the corresponding cyclic carbonates were obtained in good yields and high selectivities. 3-Chloropropylene carbonate was synthesized under extremely mild conditions of room temperature and atmosphere. The proposed mechanism was also calculated and confirmed by DFT. The palladium catalyst could be simply recycled and reused for 5 times without significant loss of activity.Download high-res image (125KB)Download full-size image

Ionic liquids-functionalized porphyrins as bifunctional catalysts for cycloaddition of carbon dioxide to epoxides

Co-reporter:Xu Jiang, Faliang Gou, Xiying Fu, Huanwang Jing

Journal of CO2 Utilization (December 2016) Volume 16() pp:264-271

Publication Date(Web):1 December 2016

DOI:10.1016/j.jcou.2016.08.003

•New and efficient ionic liquids-functionalized metalloporphyrin catalysts were designed and synthesized for the PO/CO2 cycloaddition.•Catalysts demonstrated excellent reactivity and selectively.•The catalytic performance is strongly dependent on both halogen anionic species and cationic structural nature.Six ionic liquids-functionalized metallophorphyrins have been designed, prepared and characterized by NMR, MS and elemental analysis. They were applied as efficient bifunctional catalysts to the cycloaddition of epoxides and carbon dioxide without additive and organic solvent yielding cyclic carbonates. 5,15-Di[4-(4-tributylammoniobutoxy)phenyl]porphyrin zinc(II) dibromide (JBp) and 5,15-di[3-(4-tributylammoniobutoxy)phenyl]porphyrin zinc(II) dibromide (JBm) have been demonstrated excellent activities under optimized conditions. It has been found that both the structure of porphyrin complex cations and the anion moieties would strongly affect their catalytic performance. The catalysts were versatile for the cycloaddition of CO2 to various terminal epoxides in satisfying yields with excellent selectivities. Moreover, phenoxypropylene carbonate was able to be obtained under atmosphere pressure of CO2 and in large-scale. Furthermore, a plausible mechanism involving Lewis acid-base synergistic catalysis has been proposed according to our experimental results.Download high-res image (113KB)Download full-size image

Tunable catalytic activities and selectivities of metal ion doped TiO2 nanoparticles – oxidation of organic compounds

Co-reporter:Anqi Wang and Huanwang Jing

Dalton Transactions 2014 - vol. 43(Issue 3) pp:NaN1018-1018

Publication Date(Web):2013/10/10

DOI:10.1039/C3DT51987B

A series of metal ion doped TiO2 nanoparticles (M–TiO2, M = Cr3+, Mn2+, Fe3+, V5+, Zn2+, Ni2+, Ag+, Cu2+ and Co2+) were prepared by a facile co-precipitation approach and characterized by means of ICP-AES, N2 adsorption–desorption isotherms, XRD, TEM and HRTEM. Their catalytic performance was investigated via the oxidation of organic compounds. The variation of metal ion species and doping contents allowed tuning the catalytic properties of the M–TiO2. Among them, the catalyst Cu-10 displayed excellent activity (97.5%) in the oxidation of styrene and the selectivity of benzaldehyde was as high as 99.4%. Surprisingly, the product distribution of styrene oxidation experienced a reverse trend over the Co–TiO2 catalysts with different doping amounts of cobalt ions: Co-10 was in favor of forming benzaldehyde (80.2% selectivity), in contrast with Co-15, which produced styrene oxide as the dominant product (84.7% selectivity). The M–TiO2 catalysts also showed catalytic activities for the oxidation of benzyl alcohol and toluene to generate chlorine-free benzaldehyde in excellent selectivities (>99%).

New magnetic nanocomposites of ZrO2–Al2O3–Fe3O4 as green solid acid catalysts in organic reactions

Co-reporter:Anqi Wang, Xiang Liu, Zhongxing Su and Huanwang Jing

Catalysis Science & Technology (2011-Present) 2014 - vol. 4(Issue 1) pp:NaN80-80

Publication Date(Web):2013/09/25

DOI:10.1039/C3CY00572K

Artificial photosynthesis of methanol from carbon dioxide and water via a Nile red-embedded TiO2 photocathode

Co-reporter:Yongjian Jia, Yanjie Xu, Rong Nie, Fengjuan Chen, Zhenping Zhu, Jianguo Wang and Huanwang Jing

Journal of Materials Chemistry A 2017 - vol. 5(Issue 11) pp:NaN5501-5501

Publication Date(Web):2017/02/13

DOI:10.1039/C6TA10231J

Mechanism of selective C–H cyanation of 2-phenylpyridine with benzyl nitrile catalyzed by CuBr: a DFT investigation

Co-reporter:Da-Gang Zhou, Fan Yang, Xing Yang, Chao-Xian Yan, Pan-Pan Zhou and Huan-Wang Jing