Synthesis and Thermal Studies on Some Bimetallic Mixed-Ligand Complexes Containing a Bis-Bidentate Onno Schiff Base and Alkylxanthate Ligands

Abstract

New bimetallic mixed-ligand complexes of the general formula [M₂(sal-bz)(Rxan)₂(DMF)_n], where M = Ni(II), Co(II) or Cu(II); sal-bz= dianion of a tetradentate Schiff base derived from salicylaldehyde and benzidine; xan = xanthate anion; R = methyl, ethyl or butyl; n - 2 or 4, have been prepared and characterized by elemental analyses, molar conductance, IR and electronic spectral data. The thermal decomposition of some of these complexes has been studied. The TG curves show that the decomposition takes place in two well-defined steps. The first step involves the elimination of DMF molecules and the decomposition of the alkyl xanthate via a radical mechanism. This was accompanied by the formation of an intermediate product which decomposed in a second step to the metal sulphide as the end product. Activation energies and other kinetic parameters were computed.