Thermal properties of [Co(en)2Cl2]Cl in solid state. Cis-trans isomerization of the [Co(en)2Cl2]~+ complex ion in methanol

摘要

Thermal decompositions of the trans-[Co(en)2Cl2]Cl and cis-[Co(en)2-Cl2]Cl complex isomers have been studied using the TG-FTIR and TG-DSC-MS techniques. The measurements were carried out in argon atmosphere over the temperature range 293-873 K. The influence of the configurational geometry on the pathways of thermal transformations was discussed. Furthermore, kinetic studies on the reaction of the cis-trans isomerization of the [Co(en)2Cl2]Cl complex salt in methanolic solutions were performed using UV-Vis spectrophotometry at five temperatures in the 293-313 K temperature range. The observed rate constants were computed using the "Glint" program based on the global analysis. It has been found that the cis-trans isomerization of [Co(en)2Cl2]Cl is a first order reaction. Furthermore, the cis/trans [Co(en)2Cl2]Cl isomerization proceeds according to the dissociative mechanism.