Mechanism of a one-photon two-electron process in photocatalytic hydrogen evolution from ascorbic acid with a cobalt chlorin complex

Abstract

A one-photon two-electron process was made possible in photocatalytic H-2 evolution from ascorbic acid with a cobalt(II) chlorin complex [Co-II(Ch)] via electron transfer from ascorbate to the excited state of [Ru(bpy)(3)](2+) followed by electron transfer from [Ru(bpy)(3)](+) to Co-II(Ch) with proton to give the hydride complex, which reacts with proton to produce H-2. [Co-III(Ch)](+) was reduced by ascorbate to reproduce Co-II(Ch).