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Dubourdeaux P, Blondin G, Latour JM. Mixed Valence (μ-Phenoxido) Fe II Fe III et Fe III Fe IV Compounds: Electron and Proton Transfers. Chemphyschem 2021; 23:e202100399. [PMID: 34633731 DOI: 10.1002/cphc.202100399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 10/03/2021] [Indexed: 11/08/2022]
Abstract
Mixed-valence non-heme diiron centers are present at the active sites of a few enzymes and confer them interesting reactivities with the two ions acting in concert. Related (μ-phenoxido)diiron complexes have been developed as enzyme mimics. They exhibit very rich spectroscopic properties enabling independent monitoring of each individual ion, which proved useful for mechanistic studies of catalytic hydrolysis and oxidation reactions. In our studies of such complexes, we observed that these compounds give rise to a wide variety of electron transfers (intervalence charge transfer), proton transfers (tautomerism), coupled electron and proton transfers (H. abstraction and PCET). In this minireview, we present and analyze the main results illustrating the latter aspects.
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Affiliation(s)
| | - Geneviève Blondin
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-LCBM/pmb, F-38000, Grenoble, France
| | - Jean-Marc Latour
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-LCBM/pmb, F-38000, Grenoble, France
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Coin G, Ferrier de Montal O, Dubourdeaux P, Latour J. Expedient Synthesis of 2‐Iminothiazolidines via Telescoping Reactions Including Iron‐Catalyzed Nitrene Transfer and Domino Ring‐Opening Cyclization (DROC). European J Org Chem 2020. [DOI: 10.1002/ejoc.202001379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Guillaume Coin
- Univ. Grenoble Alpes CNRS UMR 5249, CEA, LCBM/pmb 38000 Grenoble France
- Univ. Grenoble Alpes CNRS UMR 5250, DCM 38000 Grenoble France
- Present address: ETH Zürich Department of Chemistry and Applied Biosciences 8093 Zürich Switzerland
| | | | | | - Jean‐Marc Latour
- Univ. Grenoble Alpes CNRS UMR 5249, CEA, LCBM/pmb 38000 Grenoble France
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Liu Y, Tse CW, Lam KY, Chang XY, Guan X, Chao MY, Huang JS, Che CM. Intramolecular Nitrene Insertion into Saturated C-H-Bond-Mediated C-N Bond Cleavage of a Coordinated NHC Ligand. Chemistry 2019; 25:10828-10833. [PMID: 31271674 DOI: 10.1002/chem.201903012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Indexed: 01/07/2023]
Abstract
Ruthenium(II) complexes bearing a tridentate bis(N-heterocyclic carbene) ligand reacted with iminoiodanes (PhI=NR) resulting in the formation of isolable ruthenium(III)-amido intermediates, which underwent cleavage of a C-N bond of the tridentate ligand and formation of an N-substituted imine group. The RuIII -amido intermediates have been characterized by 1 H NMR, UV/Vis, ESI-MS, and X-ray crystallography. DFT calculations were performed to provide insight into the reaction mechanism.
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Affiliation(s)
- Yungen Liu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China
| | - Chun-Wai Tse
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P. R. China
| | - Kar-Yee Lam
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P. R. China
| | - Xiao-Yong Chang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China
| | - Xiangguo Guan
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P. R. China
| | - Meng-Yao Chao
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China
| | - Jie-Sheng Huang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P. R. China
| | - Chi-Ming Che
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China.,Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P. R. China
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Kaczmarek MA, Malhotra A, Balan GA, Timmins A, de Visser SP. Nitrogen Reduction to Ammonia on a Biomimetic Mononuclear Iron Centre: Insights into the Nitrogenase Enzyme. Chemistry 2017; 24:5293-5302. [PMID: 29165842 PMCID: PMC5915742 DOI: 10.1002/chem.201704688] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Indexed: 11/05/2022]
Abstract
Nitrogenases catalyse nitrogen fixation to ammonia on a multinuclear Fe‐Mo centre, but their mechanism and particularly the order of proton and electron transfer processes that happen during the catalytic cycle is still unresolved. Recently, a unique biomimetic mononuclear iron model was developed using tris(phosphine)borate (TPB) ligands that was shown to convert N2 into NH3. Herein, we present a computational study on the [(TPB)FeN2]− complex and describe its conversion into ammonia through the addition of electrons and protons. In particular, we tested the consecutive proton transfer on only the distal nitrogen atom or alternated protonation of the distal/proximal nitrogen. It is found that the lowest energy pathway is consecutive addition of three protons to the same site, which forms ammonia and an iron‐nitrido complex. In addition, the proton transfer step of complexes with the metal in various oxidation and spin states were tested and show that the pKa values of biomimetic mononuclear nitrogenase intermediates vary little with iron oxidation states. As such, the model gives several possible NH3 formation pathways depending on the order of electron/proton transfer, and all should be physically accessible in the natural system. These results may have implications for enzymatic nitrogenases and give insight into the catalytic properties of mononuclear iron centres.
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Affiliation(s)
- Monika A Kaczmarek
- Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.,Department of Chemistry, University of Warsaw, Ludwika Pasteura 1, 02-093, Warsaw, Poland
| | - Abheek Malhotra
- Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - G Alex Balan
- Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Amy Timmins
- Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Sam P de Visser
- Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
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