Multiple-Site Concerted Proton-Electron Transfer in a Manganese-Based Complete Functional Model for [FeFe]-Hydrogenase.
Angew Chem Int Ed Engl
; 60(49): 25839-25845, 2021 12 01.
Article
em En
| MEDLINE
| ID: mdl-34595813
ABSTRACT
The active site of [FeFe]-hydrogenase (H2 ase) is preorganized with an amine (azadithiolate) as a proton relay and a [4Fe4S] subunit as an electron reservoir, which together lower the overpotential for proton reduction and hydrogen oxidation by multiple-site concerted proton-electron transfer (MS-CPET). Herein, we report a mononuclear manganese complex, fac-[Mn(CO)3 (6-(2-hydroxyphenol)-2-pyridine-2-quinoline) Br] (1), as a rare model to fully mimic the functions of the H2 ase. In 1, a redox-active bidentate ligand with a pendent phenol replicates the roles of the electron reservoir and the proton relay in the enzyme. Experimental and theoretical studies revealed two consecutive MS-CPET processes in the catalytic cycle, in each of which an electron stored in the reductive ligand and a proton at the proximal phenol moiety are transferred to the Mn center in a concerted way. By virtue of this mechanism, complex 1 exhibited a low overpotential comparable to that of natural enzyme in electrochemical hydrogen production using phenol as a proton source.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Prótons
/
Complexos de Coordenação
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Hidrogenase
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Proteínas Ferro-Enxofre
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Manganês
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article