ESR and Optical Absorption Studies of Various Bis(N-salicylidenealkylaminato)copper(II) Complexes with Tetrahedrallydistorted Coordination Geometry

Abstract

Abstract The ESR and visible absorption spectra of a number of bis(N-salicylidenealkylaminato)copper(II) complexes with different kinds of alkyl groups were measured in toluene. The coordinations of these complexes in toluene are distorted towards a tetrahedral geometry to varying extents; the relationship between the degree of the distortion and the ESR and visible absorption parameters was systematically investigated. Especially, the experimental fact that the absolute values of the hyperfine coupling constant with the copper nucleus decrease with an increase in the degree of distortion was discussed. A configurational equilibrium between two species with different degrees of the distortion was found to exist for the complexes with R=isopropyl and cyclohexyl in toluene.