Reactivities of Hydroxycinnamic Acid Derivatives Involving Caffeic Acid toward Electrogenerated Superoxide in N,N-Dimethylformamide

Reactivity of (2E)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid (caffeic acid), classified as a hydroxycinnamic (HCA) derivative, toward electrogenerated superoxide radical anion (O2•−) was investigated through cyclic voltammetry, in situ electrolytic electron spin resonance spectrometry, and ultraviolet–visible spectrometry N,N-dimethylformamide (DMF), aided by density functional theory (DFT) calculations. The quasi-reversible redox dioxygen/O2•− is modified the presence caffeic acid, suggesting that O2•− scavenged proton-coupled transfer. reactivities are mediated ortho-diphenol (catechol) moiety rather than acryloyl group, experimentally confirmed comparative analyses with other HCAs. electrochemical DFT results DMF suggested concerted two-proton-coupled transfer mechanism proceeds via catechol moiety. This embodies superior kinetics scavenging acid.