A square-planar nickel dithiolate complex as an efficient molecular catalyst for the electro- and photoreduction of protons

Abstract

A square-planar nickel(II) dithiolate complex is an active molecular catalyst for both photoreduction of protons from water with a turnover number (>1500) and electroreduction of protons from weakly acidic solutions with remarkable turnover frequencies (5575 s⁻¹ at −1.92 V and 1441 s⁻¹ at −1.61 V vs. SCE). DFT calculations provide in-depth insight into the catalytic cycle of the electrochemical reaction, suggesting that the sulfur atoms play crucial roles in proton exchange and hydrogen formation.