The first ESR spin-trapping evidence for the formation of hydroxyl radical from the reaction of copper(II) complex with hydrogen peroxide in aqueous solution

The formation of hydroxyl radical (OH·) during the reaction of copper(II) ion with hydrogen peroxide (H2O2) is determined by ESR spectroscopy using water-soluble spin-traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO, 1), α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN, 2) and sodium 3,5-dibromo-4-nitrosobenzenesulphonate (DBNBS, 3).