Mechanistic Diversity in Proton-Coupled Electron Transfer between Thiophenols and Photoexcited [Ru(2,2′-Bipyrazine)₃]²⁺

Abstract

Proton-coupled electron transfer (PCET) with phenols has been investigated in considerable detail in recent years while at the same time analogous mechanistic studies of PCET with thiophenols have remained scarce. We report on PCET between a series of thiophenols and a photoexcited Ru­(II) complex, which acts as a combined electron/proton acceptor. Depending on the exact nature of the thiophenol, PCET occurs through different reaction mechanisms. The results are discussed in the context of recent studies of PCET between phenols and photoexcited d⁶ metal complexes