1
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Dual electronic effects achieving a high-performance Ni(II) pincer catalyst for CO 2 photoreduction in a noble-metal-free system. Proc Natl Acad Sci U S A 2022; 119:e2119267119. [PMID: 35998222 PMCID: PMC9436338 DOI: 10.1073/pnas.2119267119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A carbazolide-bis(NHC) NiII catalyst (1; NHC, N-heterocyclic carbene) for selective CO2 photoreduction was designed herein by a one-stone-two-birds strategy. The extended π-conjugation and the strong σ/π electron-donation characteristics (two birds) of the carbazolide fragment (one stone) lead to significantly enhanced activity for photoreduction of CO2 to CO. The turnover number (TON) and turnover frequency (TOF) of 1 were ninefold and eightfold higher than those of the reported pyridinol-bis(NHC) NiII complex at the same catalyst concentration using an identical Ir photosensitizer, respectively, with a selectivity of ∼100%. More importantly, an organic dye was applied to displace the Ir photosensitizer to develop a noble-metal-free photocatalytic system, which maintained excellent performance and obtained an outstanding quantum yield of 11.2%. Detailed investigations combining experimental and computational studies revealed the catalytic mechanism, which highlights the potential of the one-stone-two-birds effect.
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2
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Petersen HA, Alherz AW, Stinson TA, Huntzinger CG, Musgrave CB, Luca OR. Predictive Energetic Tuning of C-Nucleophiles for the Electrochemical Capture of Carbon Dioxide. iScience 2022; 25:103997. [PMID: 35310940 PMCID: PMC8927916 DOI: 10.1016/j.isci.2022.103997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/28/2021] [Accepted: 02/23/2022] [Indexed: 11/29/2022] Open
Abstract
This work maps the thermodynamics of electrochemically generated C-nucleophiles for reactive capture of CO2. We identify a linear relationship between the pKa, the reduction potential of a protonated nucleophile (Ered), and the nucleophile’s free energy of CO2 binding (ΔGbind). Through synergistic experiments and computations, this study establishes a three-parameter correlation described by the equation ΔGbind=−0.78pKa+4.28Ered+20.95 for a series of twelve imidazol(in)ium/N-heterocyclic carbene pairs with an R2 of 0.92. The correlation allows us to predict the ΔGbind of C-nucleophiles to CO2 using reduction potentials or pKas of imidazol(in)ium cations. The carbenes in this study were found to exhibit a wide range CO2 binding strengths, from strongly CO2 binding to nonspontaneous. This observation suggests that the ΔGbind of imidazol(in)ium-based carbenes is tunable to a desired strength by appropriate structural changes. This work sets the stage for systematic energetic tuning of electrochemically enabled reactive separations. CO2 binding energy was calculated for a set of N-heterocyclic carbenes (NHCs) CO2 binding energy of NHCs is widely synthetically tunable pKa, reduction potential, and CO2 binding energy correlate linearly for NHCs 3D correlation enables easy prediction of CO2 binding strength for novel NHCs
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Affiliation(s)
- Haley A. Petersen
- Department of Chemistry and Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Abdulaziz W. Alherz
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, United States
| | - Taylor A. Stinson
- Department of Chemistry and Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Chloe G. Huntzinger
- Department of Chemistry and Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Charles B. Musgrave
- Department of Chemistry and Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309, USA
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, United States
- Materials Science and Engineering Program, University of Colorado, Boulder, CO 80309, United States
- Corresponding author
| | - Oana R. Luca
- Department of Chemistry and Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO 80309, USA
- Corresponding author
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3
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Wang XZ, Meng SL, Chen JY, Wang HX, Wang Y, Zhou S, Li XB, Liao RZ, Tung CH, Wu LZ. Mechanistic Insights Into Iron(II) Bis(pyridyl)amine-Bipyridine Skeleton for Selective CO 2 Photoreduction. Angew Chem Int Ed Engl 2021; 60:26072-26079. [PMID: 34545677 DOI: 10.1002/anie.202107386] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/20/2021] [Indexed: 12/29/2022]
Abstract
A bis(pyridyl)amine-bipyridine-iron(II) framework (Fe(BPAbipy)) of complexes 1-3 is reported to shed light on the multistep nature of CO2 reduction. Herein, photocatalytic conversion of CO2 to CO even at low CO2 concentration (1 %), together with detailed mechanistic study and DFT calculations, reveal that 1 first undergoes two sequential one-electron transfer affording an intermediate with electron density on both Fe and ligand for CO2 binding over proton. The following 2 H+ -assisted Fe-CO formation is rate-determining for selective CO2 -to-CO reduction. A pendant, proton-shuttling α-OH group (2) initiates PCET for predominant H2 evolution, while an α-OMe group (3) cancels the selectivity control for either CO or H2 . The near-unity selectivity of 1 and 2 enables self-sorting syngas production at flexible CO/H2 ratios. The unprecedented results from one kind of molecular catalyst skeleton encourage insight into the beauty of advanced multi-electron and multi-proton transfer processes for robust CO2 RR by photocatalysis.
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Affiliation(s)
- Xu-Zhe Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shu-Lin Meng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jia-Yi Chen
- School of Chemistry and Chemical Engineering, Huazhong, University of Science and Technology, Wuhan, 430074, P. R. China
| | - Hai-Xu Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuai Zhou
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xu-Bing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Rong-Zhen Liao
- School of Chemistry and Chemical Engineering, Huazhong, University of Science and Technology, Wuhan, 430074, P. R. China
| | - Chen-Ho Tung
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li-Zhu Wu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
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4
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Wang X, Meng S, Chen J, Wang H, Wang Y, Zhou S, Li X, Liao R, Tung C, Wu L. Mechanistic Insights Into Iron(II) Bis(pyridyl)amine‐Bipyridine Skeleton for Selective CO
2
Photoreduction. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xu‐Zhe Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Shu‐Lin Meng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Jia‐Yi Chen
- School of Chemistry and Chemical Engineering Huazhong, University of Science and Technology Wuhan 430074 P. R. China
| | - Hai‐Xu Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Yang Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Shuai Zhou
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Xu‐Bing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Rong‐Zhen Liao
- School of Chemistry and Chemical Engineering Huazhong, University of Science and Technology Wuhan 430074 P. R. China
| | - Chen‐Ho Tung
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Li‐Zhu Wu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
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5
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Abstract
The decrease of total amount of atmospheric CO2 is an important societal challenge in which CO2 reduction has an important role to play. Electrocatalytic CO2 reduction with homogeneous catalysts is based on highly tunable catalyst design and exploits an abundant C1 source to make valuable products such as fuels and fuel precursors. These methods can also take advantage of renewable electricity as a green reductant. Mn-based catalysts offer these benefits while incorporating a relatively cheap and abundant first-row transition metal. Historically, interest in this field started with Mn(bpy-R)(CO)3X, whose performance matched that of its Re counterparts while achieving substantially lower overpotentials. This review examines an emerging class of homogeneous Mn-based electrocatalysts for CO2 reduction, Mn complexes with meridional tridentate coordination also known as Mn pincers, most of which contain redox-active ligands that enable multi-electron catalysis. Although there are relatively few examples in the literature thus far, these catalysts bring forth new catalytic mechanisms not observed for the well-established Mn(bpy-R)(CO)3X catalysts, and show promising reactivity for future studies.
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6
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Wang XZ, Meng SL, Xiao H, Feng K, Wang Y, Jian JX, Li XB, Tung CH, Wu LZ. Identifying a Real Catalyst of [NiFe]-Hydrogenase Mimic for Exceptional H 2 Photogeneration. Angew Chem Int Ed Engl 2020; 59:18400-18404. [PMID: 32667116 DOI: 10.1002/anie.202006593] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/22/2020] [Indexed: 11/09/2022]
Abstract
Inspired by the natural [NiFe]-H2 ase, we designed mimic 1, (dppe)Ni(μ-pdt)(μ-Cl)Ru(CO)2 Cl to realize effective H2 evolution under photocatalytic conditions. However, a new species 2 was captured in the course of photo-, electro-, and chemo- one-electron reduction. Experimental studies of in situ IR spectroscopy, EPR, NMR, X-ray absorption spectroscopy, and DFT calculations corroborated a dimeric structure of 2 as a closed-shell, symmetric structure with a RuI center. The isolated dimer 2 showed the real catalytic role in photocatalysis with a benchmark turnover frequency (TOF) of 1936 h-1 for H2 evolution, while mimic 1 worked as a pre-catalyst and evolved H2 only after being reduced to 2. The remarkably catalytic activity and unique dimer structure of 2 operated in photocatalysis unveiled a broad research prospect in hydrogenases mimics for advanced H2 evolution.
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Affiliation(s)
- Xu-Zhe Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shu-Lin Meng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hongyan Xiao
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Ke Feng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jing-Xin Jian
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xu-Bing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chen-Ho Tung
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li-Zhu Wu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
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7
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Wang X, Meng S, Xiao H, Feng K, Wang Y, Jian J, Li X, Tung C, Wu L. Identifying a Real Catalyst of [NiFe]‐Hydrogenase Mimic for Exceptional H
2
Photogeneration. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Xu‐Zhe Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Shu‐Lin Meng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Hongyan Xiao
- Key Laboratory of Bio-inspired Materials and Interfacial Science Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
| | - Ke Feng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Yang Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Jing‐Xin Jian
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Xu‐Bing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Chen‐Ho Tung
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
| | - Li‐Zhu Wu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
- School of Future Technology University of Chinese Academy of Sciences Beijing 100049 China
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8
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Xie L, Tian J, Ouyang Y, Guo X, Zhang W, Apfel U, Zhang W, Cao R. Water‐Soluble Polymers with Appending Porphyrins as Bioinspired Catalysts for the Hydrogen Evolution Reaction. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003836] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Lisi Xie
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
| | - Jia Tian
- Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Yingjie Ouyang
- Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Xinai Guo
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
| | - Weian Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Ulf‐Peter Apfel
- Ruhr-Universität Bochum Fakultät für Chemie und Biochemie Anorganische Chemie I Universitätsstrasse 150 44801 Bochum Germany
- Fraunhofer UMSICHT Osterfelder Strasse 3 46047 Oberhausen Germany
| | - Wei Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
| | - Rui Cao
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
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9
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Xie L, Tian J, Ouyang Y, Guo X, Zhang W, Apfel U, Zhang W, Cao R. Water‐Soluble Polymers with Appending Porphyrins as Bioinspired Catalysts for the Hydrogen Evolution Reaction. Angew Chem Int Ed Engl 2020; 59:15844-15848. [DOI: 10.1002/anie.202003836] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/10/2020] [Indexed: 01/09/2023]
Affiliation(s)
- Lisi Xie
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
| | - Jia Tian
- Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Yingjie Ouyang
- Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Xinai Guo
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
| | - Weian Zhang
- Shanghai Key Laboratory of Functional Materials Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 China
| | - Ulf‐Peter Apfel
- Ruhr-Universität Bochum Fakultät für Chemie und Biochemie Anorganische Chemie I Universitätsstrasse 150 44801 Bochum Germany
- Fraunhofer UMSICHT Osterfelder Strasse 3 46047 Oberhausen Germany
| | - Wei Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
| | - Rui Cao
- Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an 710119 China
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10
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Myren THT, Alherz A, Stinson TA, Huntzinger CG, Lama B, Musgrave CB, Luca OR. Metalloradical intermediates in electrocatalytic reduction of CO 2 to CO: Mn versus Re bis-N-heterocyclic carbene pincers. Dalton Trans 2020; 49:2053-2057. [PMID: 31971534 DOI: 10.1039/c9dt04691g] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This work examines the relative reactivities of ReI and MnI tricarbonyl pyridine-2,6-bis-N-heterocyclic carbene pincers M(CO)3CNCBnX (M = Re, Mn and X = Cl and Br) towards catalysis for the electrochemical conversion of CO2 to CO. Unlike prior well-studied group VII catalysts, Mn(CO)3CNCBnX is extraordinarily active, while the new Re(CO)3CNCBnX complex surprisingly does not exhibit catalytic response. DFT calculations shed light on this puzzling behavior and show that the redox-active pyridine-2,6-bis-N-heterocyclic carbene ligand facilitates the reduction of the ground-state complexes; however, the extent of electronic delocalization in the reduced intermediates differs in the degree of metalloradical character. The highly-active Mn(CO)3CNCBnX complex proceeds through an intermediate with nucleophilic metalloradical character in which 66% of the unpaired electron spin resides on Mn. In contrast, Re(CO)3CNCBnX reduction proceeds through an intermediate with less metalloradical character in which only 38% of the unpaired spin is localized on Re with the remainder delocalized over the ligand. The energetic penalty of the electron delocalization of an electron on the ligand affects the M-CO bond strengths and related kinetic barriers. We discuss these observations in the context of turnover-enabling effects in CO2 reductions mediated by group VII NHC pincer molecular electrocatalysts.
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Affiliation(s)
- Tessa H T Myren
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA.
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11
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Myren THT, Alherz A, Thurston JR, Stinson TA, Huntzinger CG, Musgrave CB, Luca OR. Mn-Based Molecular Catalysts for the Electrocatalytic Disproportionation of CO2 into CO and CO32–. ACS Catal 2020. [DOI: 10.1021/acscatal.9b04773] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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12
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Myren THT, Lilio AM, Huntzinger CG, Horstman JW, Stinson TA, Donadt TB, Moore C, Lama B, Funke HH, Luca OR. Manganese N-Heterocyclic Carbene Pincers for the Electrocatalytic Reduction of Carbon Dioxide. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00535] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | | | | | | | | | | | - Curtis Moore
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093-0358, United States
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