PNNL

Abstract

A mononuclear nickel(II) bis(diphosphine) complex [Ni(PMe2NPh2)2](BF4)2 (PMe2NPh2 = 1,5-diphenyl-3,7-dimethyl-1,5-diaza-3,7-diphosphacyclooctane) has been synthesized. This complex is an efficient electrocatalyst for hydrogen production by proton reduction. Using [(DMF)H]OTf as the acid and with added water, a turnover frequency of 6,700 s-1 was obtained. Based on the understanding of previous studies and the measured hydride donor ability of [HNi(PMe2NPh2)2](BF4) (?G?H- = 54.0 kcal/mol), this complex was anticipated to have the highest turnover frequency for catalytic H2 production of any complex of this class reported to date. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.