Dinuclear copper(II) complex of containing N,N-diisopropyl,N'-3-propylamide-ethylenediamine and dihydroxo bridge; Solvatochromic and Thermochromic

Abstract

The synthesis and characterization of dinuclear [LCu(m-OH)2CuL](ClO4)2, complex with a tridentate N,N-diisopropyl,N'-3-propylamide-ethylenediamine hemilabile ligand (abbreviated L) is reported. The dinuclear complex was characterized by elemental analyses, molar conductance, thermal analysis and spectral studies. In the complex two copper centers are 5-coordinated and bridged through two hydroxo groups. Thermo- and solvatochromic behaviors of the complex were investigated by visible spectroscopy. Its reversible thermochromism (blue ↔ green) is due to breakage and re-coordination of Cu-O(amide) moiety in acetonitrile solution. The solvent-dependent absorption maxima, max, was studied by a stepwise multiple linear regression (SMLR) analysis to determine the best model describing the resulting positive solvatochromism. The statistical results demonstrated that among different solvent parameters, donor number (DN) is a dominant parameter responsible for the redshift in the d-d absorption band of the complexes with increasing its values.