ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 32, Number 4
JKCSEZ 32(4)
August 20, 1988 

We studied the aquation reaction of s-cis-[Co(eee)Cl2]+] and s-cis-[Co(eee)Br2]+ complex ions under the various temperatures and pressures. In these complexes eee is NH2-CH2CH2-S-CH2CH2-NH2. The rate law of the aquation reactions of these two complexes obeys Rate = kobsd[CO(Ⅲ)], where rate constants of s-cis-[Co(eee)Cl2]+ and s-cis-[Co(eee)Br2]+ respectively are 0.687 × 10^-4sec^-1 and 4.10 × 10^-4sec^-1 in condition of 0.1M HClO4 and 40℃. In the same condition, the activation entropies of s-cis-[Co(eee)Cl2]+ and s-cis-(Co(eee)Br2]+ complexes respectively are -15.5 eu and -7.54eu, and the activation volumes are -4.6cm3mole-1 and -4.2cm3mole-1. From these data, we could infer the mechanism of the aquation reaction as the interchange dissociation (Id) mechanism.