Kinetics and mechanisms of redox reactions in aqueous solution. Part 4. Oxidation of diols by aquamanganese(III) ions in aqueous perchloric acid

Abstract

The kinetics of oxidations of butane-1,4-, pentane-1,5-, and hexane-1,6-diols and of 3-methoxybutan-1-ol by aquamanganese(III) ions have been investigated in aqueous perchloric acid at constant ionic strength (4 mol dm^–3). The reaction has a first-order dependence both on [Mn^III] and [Substrate], but is independent of [Mn^II]. The rate decreases with increasing [H⁺] at constant ionic strength, becoming less sensitive at >3 mol dm^–3 HClO₄. The present rate data do not help to distinguish between inner- and outer-sphere mechanisms, although complex formation is indicated by spectrometry. A probable mechanism is suggested and the activation parameters are reported.