Kinetic studies on the deamination of [Co(en)3](NCS)3

The loss of ethylenediamine from [Co(en)₃](NCS)₃ has been studied using isothermal weight loss methods. The reaction has been found to be catalyzed by NH₄SCN and piperidine hydrothiocyanate, and the reaction appears first order in catalyst. However, the reaction proceeds so slowly without a catalyst present that a reliable activation energy could not be obtained. For the catalyzed process, the activation energy appears to decrease slightly as the amount of catalyst used is increased, although the results are inconclusive when NH₄SCN is the catalyst. When piperidine hydrothiocyanate is the catalyst, the activation energy appears to decrease from 37.7 kcal mole^?1 to 29.4 kcal mole^?1 as the amount of catalyst increases from 0.5 to 8.0 mole percent. In all cases, the product turned dark after a few hours indicating some reduction as a complicating feature.