Cobalt complex containing pyrrol-2-yl-methanone as the light driven pre-catalyst to the oxidation of water

摘要

The cobalt complex [(PPMdpa)CoCl2] (Col) (PPMdpa= 4-((bis(pyridin-2-ylmemyl)amino)methyl)phenyl-3,5-dimethyl-1H-pyrrol-2-yl-methanone) was characterized by X-ray crystal structure and spectroscopic methods. The electrochemical analysis confirms the reduction of dioxygen formed at the working electrode in the Col -H2O system. A catalytic current increases with increasing pH, evidencing the involvement of a proton in the initial stage of electrochemical catalysis. The light driven catalytic water oxidation was supported by the presence of the shifted cathodic wave at — 0.62 V, (pH 8.5) and obvious oxygen evolution when irradiated with LED light Thus, Col can be a pre-catalyst to the oxidation of water without using ruthenium complexes as the photo-sensitizer and Na2S2O8 as the electron acceptor. [(PPMdpa)CoCl2]-H2O system is a blue LED light driven dioxygen evolving system.