Mixed valence properties of a new binuclear complex, [(edtaH)Ru IIINCRu II(CN) 5] 4− and kinetic studies of the aqua substitution reaction in Ru III(edta)(H 2O) − by Ru(CN) 64−

Abstract

A new asymmetric mixed valence complex, K 4[(edtaH)Ru IIINCRu II(CN) 5]·2H 2O, has been synthesized by aqua substitution reaction of [Ru(edtaH)H 2O] by K 4Ru(CN) 6. Kinetic studies revealed an associative mechanism for the substitution reaction with a second order rate constant 13.8±0.6 M −1s −1 at 25°C and pH = 5.0. This complex shows an MMCT maximum at 682 nm in water at 25°C. Thermochronism of the MMCT band has been discussed. On the basis of α 2 (ground state delocalisation) and H AB (coupling integral) values this complex can be categorized as a Robin-Day class-II type complex.