
%0 Journal Article
%A Chin, LF 
%A Millen, WA 
%A Watts, DW 
%T Octahedral cobalt(III) complexes in dipolar aprotic solvents. I. The substitution of thiocyanate into the <I>cis</I>-Chlorodimethylsulphoxidobisethylenediaminecobalt(III) ion in anhydrous dimethylsulphoxide and NN-dimethylformamide
%J Australian Journal of Chemistry
%D 1965/04/01
%V 18
%N 4
%P 453-461
%K 
%R https://doi.org/10.1071/CH9650453
%U https://www.publish.csiro.au/paper/CH9650453 
%X The substitution of thiocyanate ion into the cis-chlorodimethylsulphoxidobisethylenediaminecobalt(III) ion, cis-(Coen2(DMSO)Cl)2+, has been studied in the solvents dimethylsulphoxide (DMSO) and NN-dimethylformamide (DMF). In DMSO the reaction shows second-order characteristics which are accounted for by an ion-pair dissociative mechanism (SNIIP). The activation energy is 30.1 kcal mole-1.  In DMF the entry is first-order, the rate determining step being solvolysis to the intermediate cis-(Coen2(DMF)Cl)2+ which has been isolated as the nitrate. In high thiocyanate concentrations the rate shows some thiocyanate dependence due to the competition of ion-paired thiocyanate with the DMF solvent for coordination following the DMSO dissociation. The activation energy for this substitution is 17.5 kcal mole-1. 
