Kinetics and Mechanism of Substitution of Chloride Ion in trans-[Co(en)2Cl2]+ by Organic Bases in Dimethyl Acetamide Solution M. Asadi* and K. Mohammadi Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454, Iran� (Received 8 June 2003, Accepted 29 September 2003) ����� The kinetics of substitution of chloride ion in trans-dichlorobis(ethylenediamine) cobalt(III) cation by five organic bases (diethylamine, triethylamine, benzylamine, t-butylamine and n-propylamine) in dimethylacetamide (DMA) at ionic strength of 0.80 M NaClO4�is reported. The activation parameters for the second-order path lie on a good isokinetic line. The linear plots of kobs vs. [B], the large negative values of �S2� and the span of k2 values signify an associative mechanism. �Keywords: Kinetics, Mechanism, Substitution reaction, Organic bases | 
