Electrochemical and Mechanistic Study of Superoxide Scavenging by Pyrogallol in N,N-Dimethylformamide through Proton-Coupled Electron Transfer

Scavenging of electrogenerated superoxide radical anion (O2•?) by pyrogallol (PyH3) was investigated on the basis cyclic voltammetry and in situ electrolytic electron spin resonance spectrum N,N-dimethylformamide with aid density functional theory (DFT) calculations. Quasi-reversible dioxygen/O2•? redox couple modified presence PyH3, suggesting that O2•? scavenged PyH3 through proton-coupled transfer (PCET) involving two proton one transfer. DFT calculation suggested pre-reactive formation a hydrogen-bond (HB) complex subsequent concerted two-proton-coupled characterized catechol moiety is plausible mechanism embodies superior kinetics scavenging as shown electrochemical results. Furthermore, it clarified three hydroxyl groups promote HB complex, comparative analyses using related compounds, resulting promotion scavenging.