Hydrogen Evolution Mediated by Cobalt Diimine‐Dioxime Complexes: Insights into the Role of the Ligand Acid/Base Functionalities.
Dongyue Sun, Aparna Karippara Harshan, Jacques Pécaut, Sharon Hammes‐Schiffer, Cyrille Costentin, Vincent Artero
Abstract
Abstract The benchmarking of the performance for H 2 evolution of cobalt diimine‐dioxime catalysts is provided based on a comprehensive study of their catalytic mechanism. The latter follows an ECE'CC pathway with intermediate formation of a Co(II)‐hydride intermediate and second protonation possibly at a basic site of the ligand, acting as a proton relay. This suggests an intramolecular coupling between the hydride and protonated ligand as the proton concentration‐independent rate‐determining step controlling the turnover frequency for H 2 evolution.
Topics & Concepts
DiimineProtonationCobaltLigand (biochemistry)ChemistryCatalysisHydrideIntramolecular forceProtonHydrogenPhotochemistryMedicinal chemistryStereochemistryInorganic chemistryOrganic chemistryReceptorPhysicsIonBiochemistryQuantum mechanicsMetalloenzymes and iron-sulfur proteinsElectrocatalysts for Energy ConversionCO2 Reduction Techniques and Catalysts