Bin Li

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Name: 李彬; Bin Li

Organization: Tianjin University

Department: School of Chemical Engineering and Technology

Title: Associate Professor

TOPICS

Polymer

Stimuli Responsive Polymers Stimuli Responsive Polymers Temperature Responsive Polymers

Inorganic Chemistry

hydrogenase models

Chemicals
References

Biomimetic synthesis of micro/nanostructured tubular TiO2 photocatalyst: adjusting the shape of the outer tube wall from nanoparticles to interlaced nanofibers and nanobelts

Co-reporter:Guanghui Zhang;Tianyong Zhang;Xia Zhang;Li Hai;Xingwei Chen;Ping Du

CrystEngComm (1999-Present) 2017 vol. 19(Issue 17) pp:2312-2319

Publication Date(Web):2017/05/02

DOI:10.1039/C7CE00374A

In this study, hierarchical micro/nanostructured tubular TiO2 photocatalysts were fabricated with the fluff of the chinar tree (FCT) as a biological template and titanium tetrachloride (TiCl4) as a precursor through an impregnation–calcination method. The structure, morphology and optical properties were extensively characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption, Fourier-transform infrared spectroscopy (FTIR), UV-vis diffused reflectance spectroscopy (UV-vis) and photoluminescence (PL) spectra. The results indicated that the FCT played pivotal roles as a template and inducer to assemble the tubular micro/nanostructure. Interestingly, the morphologies and structures of the outer tube wall of the obtained materials could be controlled and tailored by adjusting the dosages of TiCl4. In addition, the structures of the outer tube wall of the samples could be tuned from cross-linked nanobelts to interlaced nanofibers, and then spherical-likely nanoparticles by adjusting the dosages of TiCl4. Moreover, the as-prepared TiO2 material exhibited a 99.8% photocatalytic degradation rate for 15 mg L−1 rhodamine B (RhB) in 30 min under a 300 W mercury lamp. Compared with P25, the obtained TiO2 had superior photocatalytic activity. Furthermore, the hierarchical micro/nanostructured tubular TiO2 was easily recycled and had excellent photocatalytic stability.

Direct synthesis of phenol by novel [FeFe]-hydrogenase model complexes as catalysts of benzene hydroxylation with H2O2

Co-reporter:Xia Zhang;Tianyong Zhang;Guanghui Zhang;Li Hai;Xiaoyuan Ma;Wubin Wu

RSC Advances (2011-Present) 2017 vol. 7(Issue 5) pp:2934-2942

Publication Date(Web):2017/01/04

DOI:10.1039/C6RA27831K

Three new [FeFe]-hydrogenase model complexes, μ-(SCH(CH2CH3)CH2S)–Fe2(CO)6 (complex 1), μ-(SCH(CH2CH3)CH2S)–Fe2(CO)5PCy3 (complex 2) and μ-(SCH(CH2CH3)CH2S)–Fe2(CO)5PPh3 (complex 3) were prepared. The structures of complexes 1–3 were characterized by FT-IR, UV-vis, 1H, 13C, 31P NMR spectra and single-crystal analyses. The electron density of these model complexes was studied by IR spectra, UV spectra and electrochemical analysis and evaluated against their respective catalytic performances. The CV (cyclic voltammetry) study of complex 2 showed a less positive oxidation event at 0.6 V and a more negative reduction event at −1.94 V, which is in accordance with the enlargement of electron density at diiron centers when CO were substituted by better electron donor ligands. Of all these three complexes, complex 2 exhibited the best catalytic activity, with a yield of phenol of up to 24.6% and selectivity up to 92%, which is consistent with its higher electron density of the Fe–Fe bond. This study revealed the correlations between the electron density of the catalytic site of catalysts and their performance in catalytic hydroxylation of benzene. Based on these experimental results, a catalytic oxidation mechanism via an Fe2+–μ-O–Fe2+ intermediate as oxygen transfer reagent has been proposed.

Reversible isomerization of a novel [FeFe]‑hydrogenase model complex and water-promoted electrocatalytic proton reduction

Co-reporter:Li Hai, Tianyong Zhang, Xia Zhang, Guanghui Zhang, Bin Li, Shuang Jiang, Xiaoyuan Ma

Electrochemistry Communications 2017 Volume 82(Volume 82) pp:

Publication Date(Web):1 September 2017

DOI:10.1016/j.elecom.2017.07.025

•μ-(SCH(CH2CH3)CH2S)–Fe2(CO)4(κ2-DPPE) (complex 1), which can be regarded as the active site model of [FeFe]-hydrogenase, was synthesized and characterized.•The reversible transition of complex 1 under N2 and CO atmosphere was observed by CV and IR, and a possible isomerization mechanism was proposed.•A small amount of H2O (CH3CN: H2O = 50:1, v/v) can increase the efficiency of electrocatalytic proton reduction of complex 1.•CO atmosphere or addition of H2O in CH3CN can trigger the same inversion of configuration of complex 1.μ-(SCH(CH2CH3)CH2S)-Fe2(CO)4(κ2-DPPE) (complex 1, DPPE is 1,2-bis (diphenylphosphor) ethane), which can be regarded as a model of the [FeFe]‑hydrogenase active site, was synthesized and characterized. The reversible isomerization of complex 1 under N2 and CO atmosphere was demonstrated by cyclic voltammetry, IR spectroscopy and 31P NMR. Furthermore, we discovered that both the presence of a CO atmosphere and the addition of H2O can independently trigger the same inversion of configuration of complex 1. The electrocatalytic proton reduction capacity of 1 was evaluated under varying conditions. It was found that addition of a little H2O to CH3CN can facilitate its efficiency of electrocatalytic proton reduction. The possible mechanism of transition between axial/basal and dibasal isomers and the function of H2O in the electrocatalytic reaction are discussed.Download high-res image (192KB)Download full-size image

Facile synthesis of TiO2 hierarchical tubes with enhanced photocatalytic activity

Co-reporter:Guanghui Zhang, Tianyong Zhang, Bin Li, Shuang Jiang, Xia Zhang, Li Hai, Xingwei Chen, Mingyue Song, Ping Du

Materials Research Bulletin 2017 Volume 94(Volume 94) pp:

Publication Date(Web):1 October 2017

DOI:10.1016/j.materresbull.2017.06.014

•The fluff of chinar tree was employed as template and inducer for preparing hierarchical micro/nanostructured tubular TiO2.•The wall of the micro/nanostructured tubular TiO2 is assembled with spherical-likely nanoparticles.•The resultant TiO2 exhibits favorable photocatalytic activity and good recyclability.Hierarchical micro/nanostructured tubular TiO2 were prepared by impregnation-calcination method with FCT (the fluff of the chinar tree) as biological template and titanium tetrachloride as precursor. The resultant samples possess curly tubular structure and the exterior outline of the samples look like fried dough twist. Moreover, the wall of the tube is assembled with spherical-likely nanoparticles. Apparently in the process of preparation, the FCT played pivotal roles as substrate and inducer for assembling the curly tubular structure of micro/nanostructured TiO2. Furthermore, the micro/nanostructured TiO2 have abundant pore structures and large surface area, which are beneficial to the improvement of photocatalytic activity. Under UV light irradiation, the as-prepared TiO2 exhibits nearly 100% photocatalytic decolorization rate in 30 min and 90% TOC (total organic carbon) degradation rate in 60 min for dye methyl orange (MO).Hierarchical micro/nanostructured tubular TiO2 were prepared by impregnation-calcination method with FCT (the fluff of the chinar tree) as biological template and titanium tetrachloride as precursor. The resultant TiO2 samples possess curly tubular structure and the exterior outline of the samples look like fried dough twist. Moreover, the wall of the tube is assembled with spherical-likely nanoparticles. During the bio-inspired synthetic process, the FCT plays important roles as template and inducer for assembling the tubular micro/nanostructure. Furthermore, the resultant TiO2 exhibits favorable photocatalytic activity and good stability for degrading methyl orange under UV light irradiation.Download high-res image (131KB)Download full-size image

Catalytic hydroxylation of phenol to dihydroxybenzene by Fe(II) complex in aqueous phase at ambient temperature

Co-reporter:Li Hai, Tianyong Zhang, Xia Zhang, Guanghui Zhang, Bin Li, Shuang Jiang, Xiaoyuan Ma

Catalysis Communications 2017 Volume 101(Volume 101) pp:

Publication Date(Web):1 November 2017

DOI:10.1016/j.catcom.2017.08.001

•A novel iron carbonyl complex was synthesized and characterized.•This complex served as efficient catalyst in phenol hydroxylation.•Hydroxylation could be conducted in aqueous phase at ambient temperature (20 °C).Inspired by natural [Fe]-hydrogenase, mono-iron complex FeII(CO)3I3-[trimethylpyridine-H] (complex 1) was synthesized and characterized by IR, 1H NMR, 13C NMR, EA. The singe crystal structure of the complex 1 was characterized by single crystal X-ray diffraction. The hydroxylation reaction of phenol to dihydroxybenzene was conducted using complex 1 as catalyst in aqueous phase at ambient temperature. Under the optimum conditions, the phenol conversion was 20.5%, dihydroxybenzene selectivity was 83.7%, catechol/hydroquinone (mol/mol) was 2.6. Complex 1 can be a promising catalyst for hydroxylation of phenol to dihydroxybenzene because of mild reaction conditions and good catalytic performance.Download high-res image (123KB)Download full-size image

Synthesis and electrochemical properties of [FeFe]-hydrogenase model complexes with acid-functionalized or base-functionalized ligands

Co-reporter:Xia Zhang;Tianyong Zhang;Guanghui Zhang

Journal of Applied Electrochemistry 2017 Volume 47( Issue 5) pp:583-591

Publication Date(Web):22 March 2017

DOI:10.1007/s10800-017-1064-3

In the presence of Me3NO in THF solution, the treatment of a diiron model complex (μ-dmedt)Fe2(CO)6 (dmedt = 2,3-butanedithiol) with carboxylic acid-functionalized (3-carboxypyridine) and amino-functionalized (4-aminopyridine) ligands afforded two new diiron model complexes, (μ-dmedt)Fe2(CO)5(3-COOHPy) (2) and (μ-dmedt)Fe2(CO)5(4-NH2Py) (3). Research on the influence of the 3-COOHPy and 4-NH2Py ligands upon the electrocatalytic characteristics of the diiron dithiolate core have been discussed in terms of spectroscopic and electrochemical findings. In the presence of HOAc in CH3CN solution, electrochemical studies show that complexes 2 and 3 can catalyse hydrogen evolution, with TOFs (the turnover frequencies) of 174.09 and 74.88 mol H2 (mol·cat)−1 h−1 cm−2 for complexes 2 and 3 at −1.96 V versus Fc+/Fc, respectively. The hydrogen evolution overpotentials of complexes 2 and 3 in the presence of HOAc in CH3CN solution were 0.73 and 0.82 V, respectively. Comparatively, complex 2 produces hydrogen at an overpotential 90 mV lower than complex 3 does. Complex 2 also has a better ability for electrocatalytic H2 production than complex 3. These studies provide a basic perception of the stereo-electronic characteristics related to the design for effective hydrogenase model complexes.Two new diiron model complexes, (μ-dmedt)Fe2(CO)5(3-COOHPy) (2), (μ-dmedt)Fe2(CO)5(4-NH2Py) (3), have been prepared, which served as efficient molecular electrocatalysts in the CH3CN solution, and the electrochemical studies show that complexes 2 and 3 can catalyse hydrogen evolution with TOFs of 174.09 and 74.88 mol H2 (mol·cat)−1 h−1 cm−2 for complexes 2 and 3 at −1.96 V versus Fc/Fc+, respectively.

Biomimetic synthesis of interlaced mesh structures TiO2 nanofibers with enhanced photocatalytic activity

Co-reporter:Guanghui Zhang, Tianyong Zhang, Bin Li, Xia Zhang, Xingwei Chen

Journal of Alloys and Compounds 2016 Volume 668() pp:113-120

Publication Date(Web):25 May 2016

DOI:10.1016/j.jallcom.2016.01.197

•A facile method was applied for preparing interlaced mesh structures TiO2 nanofibers.•The spongy white peels of pomelo peel were employed as template and induction.•The as-prepared TiO2 exhibit highly photocatalytic activity and good stability.A facile and economical method assisted by PPs (the spongy white peels of pomelo peel) was applied for preparing interlaced mesh structures TiO2 nanofibers by a liquid impregnation method followed by a calcination process in this study. And the as-prepared materials were comprehensively investigated by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra and N2 adsorption-desorption. The resultant TiO2 materials exhibit unique morphology, in which the curly nanofibers with the diameter about 90 nm interweave each other for assembling hierarchical mesh structures and there are abundant grooves on the surface of the nanofibers. During the bio-inspired synthetic process, the PPs play important roles as template and induction for forming the hierarchical mesh structures of TiO2 nanofibers. Furthermore, some of the as-prepared TiO2 samples exhibit 99% degradation rate for methyl orange in 30 min under UV light irradiation, which can be ascribed to the larger surface area and the unique hierarchical mesh structures. In addition, the stability tests of 5 cycling runs of the photocatalysts indicate that the as-prepared TiO2 nanofibers can be applied as a practical photocatalyst for degrading organic dyes under UV light irradiation. Therefore, hopefully, the strategy for preparing the TiO2 nanofibers can be extended to design many more powerful photocatalysts for the environmental remediation in the near future.The TiO2 nanofibers with interlaced mesh structures were prepared with PPs (the spongy white peels of pomelo peel) as the reactive substrate and directing template, and titanium tetrachloride (TiCl4) as titanium resource. And the as-prepared TiO2 samples exhibit highly photocatalytic activity and good stability for degrading methyl orange under UV light irradiation.

Nitrogen heterocyclic carbene containing pentacoordinate iron dicarbonyl as a [Fe]-hydrogenase active site model

Co-reporter:Shuang Jiang, Tianyong Zhang, Xia Zhang, Guanghui Zhang and Bin Li

Dalton Transactions 2015 vol. 44(Issue 38) pp:16708-16712

Publication Date(Web):01 Sep 2015

DOI:10.1039/C5DT02065D

A novel pentacoordinate mono iron dicarbonyl complex bearing a nitrogen heterocyclic carbene ligand was reported as a model of a [Fe]-hydrogenase active site, which exhibits interesting proton coupled CO binding reactivity, electro-catalytic proton reduction and catalytic transfer hydrogenation reactivity.

Synthesis and Characterization of Bio-Inspired Diiron Complexes and Their Catalytic Activity for Direct Hydroxylation of Aromatic Compounds

Co-reporter:Xiao Wang;Tianyong Zhang;Qiusheng Yang;Shuang Jiang

European Journal of Inorganic Chemistry 2015 Volume 2015( Issue 5) pp:817-825

Publication Date(Web):

DOI:10.1002/ejic.201402918

Abstract

Three [FeFe]-hydrogenase model complexes [(μ-dmedt){Fe(CO)₃}₂] [1; dmedt = SCH(CH₃)CH(CH₃)S], [(μ-dmedt){Fe(CO)₃}{Fe (CO)₂PPh₃}] (1-PPh₃), and [(μ-dmest){Fe(CO)₃}₂] [1-O; dmest = SCH(CH₃)CH(CH₃)S(O)], 1-O were synthesized and characterized. These model complexes, which are generally used as the functional biomimics of the hydrogen-producing dinuclear active site in [FeFe]-hydrogenase, were used as efficient catalysts for the selective hydroxylation of aromatic compounds to phenols under mild conditions. Because both the dithiolato-sulfur site and the Fe–Fe bond in the model complexes were possible active oxidation sites, DFT calculations were used to investigate the oxygenated products, that is, the S-oxygenated products or the Fe-oxygenated forms of the model complexes, which may be involved in the catalytic cycle. The experimental and computational results indicate that the thermodynamically favored Fe-oxygenated intermediates dominate the hydroxylation of the aromatic compounds. A possible mechanism for the hydroxylation is also proposed.

Synthesis, characterization, electrochemical properties and catalytic reactivity of N-heterocyclic carbene-containing diiron complexes

Co-reporter:Yanhong Wang, Tianyong Zhang, Bin Li, Shuang Jiang and Liao Sheng

RSC Advances 2015 vol. 5(Issue 37) pp:29022-29031

Publication Date(Web):13 Mar 2015

DOI:10.1039/C4RA15150J

(μ-dmedt)[Fe(CO)3]2 (I, dmedt = 2,3-butanedithiol) was chosen as the parent complex. A series of new model complexes, N-heterocyclic carbene (NHC) substituted (μ-dmedt)[Fe–Fe]–NHC (II, (μ-dmedt)[Fe(CO)2]2[IMe(CH2)2IMe], IMe = 1-methylimidazol-2-ylidene; III, {(μ-dmedt)[Fe2(CO)5]}2[IMe(CH2)2IMe]; IV, (μ-dmedt)[Fe2(CO)5]IMes, IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene; V, (μ-dmedt)[Fe2(CO)5]IMe, IMe = 1,3-dimethylimidazol-2-ylidene) as mimics of the [Fe–Fe]–H2ase active site were synthesized from I and characterized using solution IR spectroscopy, NMR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The electrochemical properties of complexes I–V, with and without the addition of HOAc, were investigated by cyclic voltammetry in the coordinating solvent CH3CN to evaluate the effects of different NHC ligands on the redox properties of the iron atoms of the series of complexes. It was concluded that all the new complexes are electrochemical catalysts for proton reduction to hydrogen. The symmetrically substituted cisoid basal/basal coordination complex II displays the most negative reduction potential owing to the stronger δ-donating ability of the NHC and the orientation of the NHC donor carbon as a result of the constraints of the bridging bidentate ligands. A new application for the [Fe–Fe]–NHC model complexes in the direct catalytic hydroxylation of benzene to phenol was also studied. Under the optimized experimental conditions (II, 0.01 mmol; benzene, 0.1 mL; CH3CN, 2.0 mL; H2O2, 6.0 mmol; 60 °C, 3 h), the maximal phenol yield was 26.7%.

Water-mediated promotion of direct oxidation of benzene over the metal–organic framework HKUST-1

Co-reporter:Yanfeng Liu, Tianyong Zhang, Wubin Wu, Shuang Jiang, Hao Zhang and Bin Li

RSC Advances 2015 vol. 5(Issue 69) pp:56020-56027

Publication Date(Web):19 Jun 2015

DOI:10.1039/C5RA05595D

Pretreatment of a HKUST-1 catalyst with water significantly accelerated the catalytic oxidation of benzene to phenol and hydroquinone with hydrogen peroxide as an oxidant. The corresponding oxygenates had a yield of 36.5%, and the selectivity to phenol and hydroquinone was 53.2% and 35.5%, respectively. The turnover frequency (TOF) was 35.1 h−1. Comparatively, the product yield was only 2.7% over the original HKUST-1, and the TOF was 2.6 h−1. Moreover, water treatment protected HKUST-1 from decomposition due to formation of a new oxidation mode. Therefore, the catalytic system in the presence of water opened a new door towards a facile and efficient preparation of phenol and hydroquinone.

Improved process for 2,3,5-trimethylhydroquinone manufacture: highly efficient catalytic hydrogenation of 2,3,5-trimethylbenzoquinone

Co-reporter:Tianyong Zhang;Guan Yin;Xiao Wang

Research on Chemical Intermediates 2015 Volume 41( Issue 2) pp:663-677

Publication Date(Web):2015 February

DOI:10.1007/s11164-013-1219-8

An efficient and green process of catalytic hydrogenation of 2,3,5-trimethylbenzoquinone (TMBQ) to 2,3,5-trimethylhydroquinone (TMHQ) on Pd/C catalyst using the LBA (a commercial mixed solvent) as solvent is described. The important reaction parameters (e.g. temperature, catalyst loading, initial concentration of TMBQ, hydrogen pressure, and agitation speed) have been investigated to acquire the optimal process conditions. The hydrogenation molar yield of TMHQ by HPLC analysis is 99.4 %. The solvent could be recovered by steam distillation, while the isolated TMHQ overall molar yield reaches up to 96.7 %. The deactivation of Pd/C during the reuse of catalysts was ascribed to the depositions of TMHQ and TMBQ based on various characterizations and regeneration study of catalyst. The possible catalytic hydrogenation mechanism is also discussed.

Efficient hydroxylation of aromatic compounds catalyzed by an iron(II) complex with H2O2

Co-reporter:Xiao Wang;Tianyong Zhang;Qiusheng Yang;Shuang Jiang

Applied Organometallic Chemistry 2014 Volume 28( Issue 9) pp:666-672

Publication Date(Web):

DOI:10.1002/aoc.3178

A mononuclear iron(II) complex, Et₄N[Fe(C₁₀H₆NO₂)₃], coordinated by three 1-nitroso-2-naphtholate ligands in a fac-N₃O₃ geometry, was initiated to catalyze the direct hydroxylation of aromatic compounds to phenols in the presence of H₂O₂ under mild conditions. Various reaction parameters, including the catalyst dosage, temperature, mole ratio of H₂O₂ to benzene, reaction time and solvents which could affect the hydroxylation activity of the catalyst, were investigated systematically for benzene hydroxylation to obtain ideal benzene conversion and high phenol distribution. Under the optimum conditions, the benzene conversion was 10.2% and only phenol was detected. The catalyst was also found to be active towards hydroxylation of other aromatic compounds with high substrate conversions. The hydroxyl radical formed due to the reaction of the catalyst and H₂O₂ was determined to be the crucial active intermediate in the hydroxylation. A rational pathway for the formation of the hydroxyl radical was proposed and justified by the density functional theory calculations. Copyright © 2014 John Wiley & Sons, Ltd.

Preparation and enhanced visible light catalytic activity of TiO2 sensitized with Benzimidazolone Yellow H3G

Co-reporter:Xili Shang, Bin Li, Changhai Li, Xiao Wang, Tianyong Zhang, Shuang Jiang

Dyes and Pigments 2013 Volume 98(Issue 3) pp:358-366

Publication Date(Web):September 2013

DOI:10.1016/j.dyepig.2013.03.009

•A commercial organic pigment modified TiO2 photocatalyst was prepared by a simple method.•Photocatalytic degradation of three typical organic pollutants by the modified TiO2 was studied.•The catalyst showed high visible light activity and stability.A TiO2 photocatalyst sensitized with commercial organic pigment Benzimidazolone Yellow H3G was conveniently prepared and characterized by FT-IR, UV–Vis, XRD, SEM and N2 adsorption–desorption isotherms. The adsorption capacities and photocatalytic activities of the new photocatalyst were evaluated by photocatalytic degradation of Methyl Orange, Rhodamine B and Acid Chrome Blue K under irradiation with visible light. The results indicated that the new photocatalyst extends the photoresponse of TiO2 from the UV to the visible region. The photocatalysed degradation rates of the three dyes were in the range of 89–95%. The influence of the pH of the solutions on the photocatalytic activity was investigated and the mechanism of action was also discussed. Photocatalytic activity of the catalyst is reproducible which demonstrates excellent stability and recyclability factors, which are crucial to industrial wastewater treatment.

Electrochemical catalysis investigation into the dynamic coordination properties of a pyridine-substituted [2Fe2S] model complex

Co-reporter:Xia Zhang, Tianyong Zhang, Yanhong Wang, Bin Li, Guanghui Zhang, Li Hai, Shuang Jiang

International Journal of Hydrogen Energy (28 December 2016) Volume 41(Issue 48) pp:

Publication Date(Web):28 December 2016

DOI:10.1016/j.ijhydene.2016.09.199

•A pyridine substituted [2Fe2S] model complex 1 was prepared and characterized by X-ray crystallography.•Electrochemical and IR investigation showed that a new reversible transformation reaction between complex 1 and complex 2.•Complex 1 was used as novel electrocatalyst to catalyze hydrogen evolution from HOAc and aqueous media at −1.26 V.A pyridine-substituted diiron dithiolate complex (μ-dmedt)Fe2(CO)5Py 1 was prepared as a biomimetic model for the active site of [FeFe]-hydrogenase by CO-substitution of all-carbonyl complex (μ-dmedt)[Fe(CO)3]2 [dmedt = 2,3-butanedithiol] with pyridine, which has been determined by IR, 1HNMR, elemental analysis and X-ray crystallography analysis. Electrochemical and IR investigation of the complex 1 in MeCN-[NBu4][PF6] under N2 and under CO has demonstrated that the reversible transformation reaction between the complex 1 and the acetonitrile-substituted species (μ-dmedt)Fe2(CO)5(NCCH3) 2. As in reverse transformation, a pyridine ligand is coordinated to a FeI centre, and can be replaced by a solvent molecule under appropriate conditions, which could mimic the function of the flexible coordination site in the H2ase enzymes. Electrochemical studies also show complex 1 can catalyze hydrogen evolution from HOAc and aqueous media at −1.26 V.A pyridine substituted [2Fe2S] model complex 1 was fully characterized by spectroscopic methods and single-crystal structure analysis. The investigation of complex 1 has demonstrated that a reversible transformation reaction between the complex 1 and (μ-dmedt)Fe2(CO)5(NCCH3), which could mimic the function of the flexible coordination site in the hydrogenases. Electrochemical studies showed complex 1 has the ability to catalyze hydrogen evolution from HOAc and aqueous media at −1.26 V.Figure optionsDownload full-size imageDownload high-quality image (284 K)Download as PowerPoint slide

A new nitrogen heterocyclic carbene containing diiron complex as bio-inspired catalyst for proton reduction and benzene hydroxylation

Co-reporter:Yanhong Wang, Yiwen Yang, Tianyong Zhang, Xia Zhang, Shuang Jiang, Guanghui Zhang, Bin Li

Journal of Organometallic Chemistry (15 December 2016) Volumes 825–826() pp:

Publication Date(Web):15 December 2016

DOI:10.1016/j.jorganchem.2016.10.020

•A new N-heterocyclic carbene substituted diiron complexes was synthesized and characterized.•This complex could electro-catalyzed the reduction of proton to hydrogen from both HOAc and H2O.•The catalytic hydroxylation of benzene by this complex achieved a phenol yield of 32.4% and a good selectivity.A new diiron complex (μ-dmedt)[Fe2(CO)5IPr] (2, dmedt = 2,3-butanedithiol, IPr = 1,3-bis(2,6-diisopropylphenyl) imidazol-2-ylidene) was synthesized as analogue of the active site of [Fe-Fe]-H2ases. The sterically bulky nitrogen heterocyclic carbene ligand of IPr coordinated to the iron center was introduced via CO/L substitution reaction in mild conditions. The reactivity of electrocatalytic reduction of proton and catalytic hydroxylation of benzene were explored for the developed diiron complex. Complex 2 undergoes two irreversible reduction events at ca. -2.17 V and −2.50 V and acts as an efficient electrocatalyst for proton reduction to hydrogen with both HOAc and H2O as proton source. The catalytic hydroxylation of benzene by complex 2 achieved phenol yield of 32.4% with almost 100% selectivity. The enhanced catalytic activity compared to the all carbonyl precursor and related derivatives was attributed to the good electron donating ability of introduced IPr ligand.A nitrogen heterocyclic carbene containing diiron complex, (μ-dmedt)[Fe2(CO)5IPr], is synthesized and used as a bio-inspired catalyst for both electro-chemical proton reduction and highly selective hydroxylation of benzene.