A Bioinspired Molybdenum Complex as a Catalyst for the Photo‐ and Electroreduction of Protons. Issue 47 (25th September 2015)

• Record Type: Journal Article
• Authors: Porcher, Jean‐Philippe; Fogeron, Thibault; Gomez‐Mingot, Maria; Derat, Etienne; Chamoreau, Lise‐Marie; Li, Yun; Fontecave, Marc
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 47(2015)
• Page Start: 14090
• Page End: 14093
• Publication Date: 2015-09-25
• Subjects: density functional calculations -- dithiolene ligands -- homogeneous catalysis -- hydrogen evolution reaction -- molybdenum; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201505607
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A molybdenum–dithiolene–oxo complex was prepared as a model of some active sites of Mo/W‐dependent enzymes. The ligand, a quinoxaline–pyran‐fused dithiolene, mimics molybdopterin present in these active sites. For the first time, this type of complex was shown to be active as a catalyst for the photoreduction of protons with excellent turnover numbers (500) and good stability in aqueous/organic media and for the electroreduction of protons in acetonitrile with remarkable rate constants (1030 s −1 at −1.3 V versus Ag/AgCl). DFT calculations provided insight into the catalytic cycle of the reaction, suggesting that the oxo ligand plays a key role in proton exchange. These results provide a basis to optimize this new class of H2 ‐evolving catalysts. Abstract : Second nature : A bioinspired molybdenum complex employing a quinoxaline–pyran‐fused dithiolene ligand has been synthesized for the first time. The complex was found to be an efficient and stable catalyst for the photo‐ and electroreduction of protons to form hydrogen. As suggested by DFT calculations, the oxo ligand plays a key role in facilitating protonation of a Mo–hydride intermediate and H2 formation.