title: A cobalt complex with a bioinspired molybdopterin-like ligand: a catalyst for hydrogen evolution.
abstract: Cobalt dithiolene complexes are a new class of H2-evolving catalysts. Here we describe the preparation, the structure and the catalytic activity of an original cobalt complex using a bioinspired ligand, a quinoxaline-pyran-fused dithiolene derivative (qpdt(2-)) that mimics the molybdopterin cofactor present in the active sites of formate dehydrogenases. This complex displays very good activity for electrochemical proton reduction under weak acid conditions in terms of turnover frequency, faradic yields and stability. Density functional theory calculations show that protonation of a nitrogen atom of the ligand decreases overpotentials by 520 mV and H2 formation proceeds via protonation of an intermediate Co-H hydride, with an adjacent S atom of the dithiolene ligand serving as a proton relay.
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France. yun.xu-li@college-de-france.fr marc.fontecave@college-de-france.fr.
authors.forename: Thibault
authors.initials: T
authors.lastname: Fogeron
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Porcher
authors.forename: Maria
authors.initials: M
authors.lastname: Gomez-Mingot
authors.forename: Tanya K
authors.initials: TK
authors.lastname: Todorova
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Chamoreau
authors.forename: Caroline
authors.initials: C
authors.lastname: Mellot-Draznieks
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave