Octahedral cobalt(III) complexes of the chloropentammine type. Part VIII. Temperature dependence of activation energies in the hydrolysis of chloropentammine-, cis-chloroamminebis(ethylenediamine)- and cis-chlorotriethylenetetramine-cobalt(III) cations

Abstract

The first-order rate constants for the hydrolysis of chloropentamminecobalt(III), cis-chloroamminebis(ethylenediamine)cobalt(III) and cis-chlorotriethylenetetraminecobalt(III) perchlorates in water have been carefully measured by a titrimetric method between 20° and 80° at 10° intervals. The results show that the energies of activation decrease as the temperature is raised. A bimolecular mechanism is assigned to these reactions and the temperature dependence of activation energies is briefly discussed in terms of solvation of the developing chloride ion.