Solvochromism and Thermochromism of Cobalt(II) Complexes Solubilized in Reversed Micelles

Configurational change takes place between tetrahedral and octahedral species, when cobalt(II) complexes are cosolubilized in reversed micelles formed by the cationic or ampholytic detergents in chloroform. This is accompanied by the elimination-addition reaction of ligand water from and to the metal ion in the reversed micellar core. The phenomenon is interpreted in terms of solvochromism and thermochromism. The nature and state of “naked” metal ion and “free” water molecule afforded in a highly restricted field of reversed micelles have been discussed on the basis of equilibrium constants and thermodynamic parameters for the configurational change, particular attention being given to the structure of micelles. Their resemblance to the active site of metalloenzymes is also discussed.