On the Hydrolysis of the Manganese(III) Ion.

Reduction Potentials of SO3•-, SO5•-, and S4O6•3-Radicals in Aqueous Solution

“…In a recent pulse radiolysis study, the oxidation of Mn 2+ and its sulfite complexes by SO 5 · - radicals at pH 3 was reported to take place with a rate constant between 2 × 10 8 and 2 × 10 10 L mol -1 s -1 and to depend on the nature of the species being oxidized . The standard reduction potential for the Mn 3+ /Mn 2+ couple is 1.56 V vs NHE in strongly acidic solutions, where both ions are in their aquo form . The aquo Mn 3+ ion is known to undergo stepwise deprotonation of its water molecules to form Mn(OH) 2+ and then Mn(OH) 2+ , with p K a values of −0.4 and 0.3 .…”

Kinetics of reaction between O2 and Mn(II) species in aqueous solutions

“…Properties of the aqueous species Mn 3ϩ , MnOH 2ϩ , and Mn(OH) 2 ϩ have been reported previously, e.g., by Diebler and Sutin (1964), Biedermann and Palombari (1978), Macartney and Sutin (1985), and Fronaeus et al (1998). A proposed rate expression on the basis of the foregoing is then Ϫd[Mn(II)/dt ϭ 4{O 2 ] ⌺ k i [Mn(II) i ].…”

Oxidation of manganese(II) by ozone and reduction of manganese(III) by hydrogen peroxide in acidic solution

“…Davies et al [29] base their mechanism on the assumption that the HO 2 radical can oxidize to 2ϩ Mn Mn(III) and thus reaction (8) is reversible. This assumption has later been proven faulty [19,20]. Furthermore, the role of Mn(IV) has not been recognized.…”