Solvatochromic Properties of Heteroleptic Copper(Ii) Complexes Containing N,N,N',N'-Tetramethylethylenediamine and 2-Aacetylcyclopentanone Ligands

Three new heteroleptic copper(ii) complexes, [(tmen)cu(dike)h2o]x where tmen = n,n,n',n'-tetramethylethylenediamine, dike = 2- acetylcyclopentanone anion and x = clo4 - (1), cl- (2) and br- (3) are prepared and characterized by elemental analyses, molar conductance measurements and ir and uv-vis spectroscopy techniques. the complex 1 is fairly soluble in various organic solvents and demonstrates distinctive solvatochromism. however, the solubility of complexes 2 and 3 is less than 1 and their color changes are limited to polar solvents. the influence of the solvent polarity and counter ions on the wave length maxima, λmax values of the d-d bands of the complexes have been investigated by visible spectroscopy. a multi-parametric equation has been utilized to explain the solvent effect on the d-d transition of [(tmen)cu(dike h2o)]clo4 using spss/pc software. the stepwise multiple linear regression (smlr) method demonstrated that the donor power of the solvent plays the most important role in the observed negative solvatochromism of the compound.