ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 33, Number 2
JKCSEZ 33(2)
April 20, 1989 

The heterogeneous rate constants for the electrochemical reduction by trans-[Co(en)2X2](ClO4)n (where X is cyanide, nitfite, ammonia, and isothiocyanate) at mercury and glassy carbon electrode were investigated by cyclic voltammetry, DC polarography, and by using rotating disk electrode. The good linear relationship was obtained between the activation energy of reduction and absorption wave number of complexes on glassy carbon electrode. At mercury electrode, NO2- ligated complex showed the large deviation from the linear relationship. The difference in the value of rate constants for NO2- ligated complex between mercury and glassy carbon electrode was about three order of magnitude which was much larger than the other complexes. It was suggested that NO2- ligated complex was reduced by inner-sphere mechanism on mercury electrode from the larger value of activation energy and entropy on mercury than carbon electrode.