Synthesis and characterization of diazine-ring containing hydrazones and their Zn(II) complexes

Abstract

Two new zinc(II) coordination compounds have been synthesized by the reaction of diazine-ring containing Schiff bases di(2-pyridyl) ketone phthalazine-1-hydrazone (HzDPK) and di(2-pyridyl) ketone 3chloropyridazine-6-hydrazone (HpDPK) with zinc(II) salts in acetonitrile in the presence of triethylamine. The crystal and molecular structures of the complexes and that of the ligand HpDPK were determined by singlecrystal X-ray structure analysis. In both complexes, zinc atoms are situated in distorted octahedral environments, formed by two meridionally coordinated NNN tridentate, mono-deprotonated ligands. Since the applicability of the coordination compounds depends on their thermal properties, the thermal decomposition of the ligands and their complexes was followed by simultaneous TG-DSC measurements. The desolvation process of the complexes is rather slow as a consequence of a restricted diffusion through the lattice and finishes ~ 200 ˚C. The desolvated compounds are stable up to 340 ˚C. In order to follow the solvent evaporation and to have a better insight into the decomposition mechanism of the compounds coupled TG-MS measurements were carried out.