Thermal properties of solid complexes with biologically important heterocyclic ligands

Abstract

Thermogravimetry (TG) and derivative thermogravimetry (DTG) have been applied to the investigation of the thermal behavior of the compounds Cu(2-Clbz)2(denia)2(H2O)2 (I), Cu(2-Brbz)2(denia)2(H2O)2 (II), and Cu(3-Brbz)2(denia)2(H2O)1 (III), where 2-Clbz and 2-Brbz and 3-Brbz = 2-chloro-, 2-bromo- and 3-bromobenzoate anions, denia = N,N-diethylnicotinamide, H2O = water molecules. Thermal decomposition of all studied compounds proceeds in three steps. Heating of the compounds first results in the release of water molecules. The final product of thermal decomposition of studied complexes was CuO. The thermal stability of the complexes can be ordered in the sequence: (II) < (I) < (III). IR data suggest unidentate coordination of benzoate anions to Cu(II) in complexes (I)–(III).