Thermal and spectral properties of halogenosalicylato-Cu(II) complexes

Abstract

This paper reports an investigation of thermal and spectral properties of the complexes Cu2(3,5Cl2sal)4⋅H2 O( I), Cu(3,5-Br2sal)2⋅2H2 O( II), Cu(3,5-I2sal)2⋅2H2 O( III) and Cu(5-Isal)2⋅2H2 O( IV), (where sal=salicylate). TG, DTG, DTA, IR, EPR and electronic spectra have been applied to investigate thermal and spectral properties of these complexes. The chemical composition of the complexes has been identified by means of elemental analysis and complexometric titration. Schemes of destruction of these complexes are suggested. Heating of these compounds first resulted in a release of water molecules. The thermal stability of these complexes can be ordered in the sequence: IV=I<II<III. The final product of the thermal decomposition was CuO in all cases. IR data suggested a unidentate coordination of carboxylates to Cu(II) in complexes I–IV.