THE NATURE OF MU(3)-OXOHEXAKIS(MU-ACETATO)TRIAQUATRIRUTHENIUM CATIONIC COMPLEXES ISOLATED FROM AQUEOUS PERCHLORIC ACID - CRYSTAL AND MOLECULAR STRUCTURE OF [RU3O(O2CCH3)(6)(OH2)(3)](CLO4)CENTER-DOT-2H(2)O

摘要

Evaporation of 2.0 M HClO4 eluates following cation-exchange chromatography of aqueous solutions of [Ru3O(O2CCH3)(6)(OH2)(3)](O2CCH3) has allowed crystallisation and structural characterisation of the complex [Ru3O(O2CCH3)(6)(OH2)(3)](ClO4).2H(2)O. A blue-green to purple colour change occurs in the mother liquor during the crystallisation process indicative of accompanying oxidation in solution to the purple dicationic Ru(III,III,IV) complex. Elution with more dilute (0.2 M) HClO4 solutions allows only isolation of the Rn(III,III,IV) complex due to a higher solubility and resulting oxidation by ClO4- ions prior to crystallisation. The structural analysis of [Ru3O(O2CCH3)(6)(OH2)(3)](ClO4).2H(2)O provides further support for the nonbonded character of the orbitals involved with electron transfer between the Ru(lII,III,III) and Ru(III,III,IV) forms of these complexes. Individual Ru-Ru and Ru-O distances indicate that in the Ru(III,III,IV) complex the Ru centres are valence delocalised at room temperature. [References: 4]