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

An experimental investigation is made to determine the mechanism of the aquation of [Co(en)2Cl2]+ in Hg2+ aqueous solution. The progress of reaction is followed UV/vis-spectrophotometrically by a measurment of the absorbance at a specific wavelength of Co(Ⅲ) complex as a function of time. The aquation of cis-[Co(en)2Cl2]+and trans-[Co(en)2Cl2]+ has been found to be first order and second order with respect to the concentration of Hg2+ catalyst, respectively. It has been found that the reaction rate for aquation of the trans-form is faster than that of cis-form, and that the product of either cis-form or trans-form is always in the mixture ratio of 97 % to 3 %. Plausible reaction mechanism is proposed for the reaction system on the basis of kinetic data and activation parameters. Theoretical rate equation derived from the proposed mechanism is consistent with the observed one.