Thermal decomposition of metal complexes—III: Stoicheiometry of the thermal dissociation of some hexamminecobalt (III) complexes

Abstract

The stoicheiometry and probable decomposition sequence for the thermal dissociation of [Co(NH 3) 6]X 3, where X is Cl, Br, NO 3 and [Co(NH 3) 6] 2(SO 4) 3·2·5H 2O, are presented. Differential thermal analysis and gas evolution curves are presented for each of the complexes. The data shows that the reduction of Co(III) → Co(III) is due to ammonia, forming NH 4X(X = Cl, Br or SO 4) and nitrogen. No free halogen could be detected. Due to the presence of both oxidizing and reducing groups, [Co(NH 3) 6](NO 3) 3 decomposed in a different manner than the other three compounds.