Comparison of Thermochromic Equilibria of ~o(ll) and Ni(ll) Complexes D. Lavabre, J. C. Micheau, and G. Levyi UA 470 Laboratoire des IMRCP, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex, France
Several publications in this Journal ( 1 , 2) have pointed out the interest of thermochromic equilibria for teaching purposes. A number of spectacular experiments demonstrating thermochromic behavior of Co(I1) an Ni(I1) complexes have been described (3, 4). However, there has been no comparative study of these systems. The present study was designed to evaluate two main factors: ( 1 1 the influence of tpmpernture on the equilibria, and (2) the structural changrs of the complexes mterprrred in rertns of
ligand field theory. The eauilibria were monitored by absorption spectroscopy in the Gisihle region at different
