Thermal, spectroscopic, and solvent influence studies on mixed-ligand copper(II) complexes containing the bulky ligand:: Bis[N-(p-tolyl)imino]acenaphthene

Four mixed-ligand copper(II) complexes containing the rigid bidentate nitrogen ligand bis[N-(p-tolyl)imino]acenaphthene (abb. p-Tol-BIAN) ligand are reported. These complexes, namely [Cu(p-Tol-BIAN)(2)](ClO4)(2) 1, [Cu(p-Tol-BIAN)(acac)](ClO4)2, [Cu(p-Tol-BIAN)Cl-2]3 and [Cu(pTol-BIAN)(AcOH)(2)](ClO4)(2) 4 (where acac, acetylacetonate and AcOH, acetic acid) have been prepared and characterized by elemental analysis, spectroscopic, magnetic and molar conductance measurements. ESR spectra suggest a square planar geometry for complexes 1 and 2. In complexes 3 and 4, a distorted tetrahedral arrangement around copper(II) centre was suggested. Solvatochromic behavior of all studied complexes indicates strong solvatochromism of their solutions. The observed solvatochromism is mainly due to the solute-solvent interaction between the chelate cation and the solvent molecules. Thermal properties and decomposition kinetics of all complexes are investigated. The kinetic parameters (E, A, Delta H, Delta S and Delta G) of all thermal decomposition stages have been calculated using the Coats-Redfern and other standard equations. (c) 2006 Elsevier B.V. All rights reserved.