KINETICS AND MECHANISM OF SUBSTITUTION-RE ACTIONS OF ,N-DIETHYLDITHIOCARBAMATO)ALKYLXANTHATOCOBALT(III) WITH DIPROPYLAMINE AND DI-N-BUTYLAMINE IN METHANOL

The title reactions with R = Me, Et, n-Pr were studied in a temperatur e range of 25 similar to 40 degrees C by spectrophotometry. It was fou nd that the rate with respect to [complexp] is unity and that to [amin e] is fractional. A linear relationship between [amine]/K-obs and [ami ne] was observed, where K-obs stands for pcsudo-first-order rate costa nt. The rate increases with the increase in water content of the solve nt. A mechanism involving a preequilibrium of an adduct formation betw een the complex and amine was proposed. The equation derived from the mechanism explained all the experimental results and the preequilibriu m constants, rate constants of the rate-evaluated.