Synthesis and Thermal Behaviour of Co(II), Ni(II) and Cu(II) Complexes of N,N-di-n-propyl-N?- (2-chlorobenzoyl)thiourea

Abstract

The Co(II), Ni(II) and Cu(II) complexes of N,N-di-n-propyl-N′-(2- chlorobenzoyl)thiourea were synthesized and the thermal behaviour of all complexes was studied by differential thermal analysis and thermal gravimetry methods. A GC-MS combined system was used to identify the decomposition products. The pyrolytic end products were identified by X-ray powder diffraction method. Both nickel and copper complexes decomposed in three stages, but cobalt complex decomposed in two stages. End products of the decomposition reactions were identified as Ni₃S₂, Co₄S₃ and Cu_1.96S. The decomposition of the complexes begins with breakage the longer metal-oxygen bond in chelate ring, since these complexes decompose at higher temperatures proportional to 1/metal-ligand bond length.