Mechanisms of peroxide decomposition. An EPR investigation of the reactions between some transition metal ions (TiIII, FeII, CuI) and monoperoxyphthalic acid and its anion
Abstract
Continuous-flow and spin-trapping experiments have been employed in conjunction with EPR spectroscopy to investigate the metal-ion induced decomposition of magnesium monoperoxy-phthalate (MMPP) in aqueous solution (at pH ca. 2 and 6). As with the corresponding reactions of peroxymonosulphate (HOOSO3–) it is shown that the behaviour of CuI(which leads to the formation of ˙OH and ArCO2–, Ar = 2-C6H4CO2H) is in complete contrast with that of TiIII and FeII, both of which bring about electron transfer to give ArCO2˙ and OH–. Some subsequent reactions of ArCO2˙ and Ar˙, formed by rapid decarboxylation, have been studied.