Radiolytic Studies of Ruthenium Oxo-Acetato Trinuclear Complexes in Acetonitrile

Article abstract of DOI:10.1021/j100131a058

Redox reactions of the ruthenium(III,III,III) and ruthenium(III,III,II) trinuclear cluster complexes PF6 and Ru3(μ3-O)(μ-CH3COO)6(py)3, (Ru(333) and Ru(332), respectively) in acetontrile were studied by pulse radiolysis.Irradiation of deaerated Ru(333) acetonitrile solutions induced one-electron reduction of the trinuclear Ru(333) center by the acetonitrile radical anion, CH3CN(*-), to Ru(332).When Ru(332) was used as a parent complex, irradiation afforded Ru(322).The yield of CH3CN(*-) was evaluated to be 0.21 μmol J^-1.In aerated solutions, Ru(333) was competitively reduced by CH3CN(*-) with a rate constant of 6.1 x 10¹⁰ M^-1 s^-1 and the superoxide ion, O2(-), with a rate constant of 3.5 x 10⁹ M^-1 s^-1 at 14 deg C.Ru(332) once produced decayed to regenerate Ru(333) in 100-300 μs after the electron-pulse irradiation.Oxidation of Ru(332) by the peroxyl radical, (*)OCH2CN, to Ru(333) with a rate constant of 2.7 x 10⁹ M^-1 s^-1 was confirmed.The whole reaction scheme for the radiation-induced processes is discussed.