Synthesis, characterization and thermogravimetric analysis of Co(II), Ni(II), Cu(II) and Zn(II) complexes supported by ONNO tetradentate Schiff base ligand derived from hydrazino benzoxazine

A new series of Co(II), Ni(II), Cu(II) and Zn(II) metal complexes of a novel ligand 3-(2-(1-(2,4-DihydroxyPhenyl)ethylidene)hydrazinyl)-2H-benzo[b][1,4]oxazin-2-one, (DPE-HBO) were prepared and characterized. Microwave synthesis of the ligand was also carried out which gave a high increase in its yield within very short time. 3D molecular modeling structure of the ligand is obtained by using ArgusLab software. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analysis, thermal, infrared, electronic spectra, magnetic moments and conductivity measurements. ESR spectrum of Cu(II) complex is studied. All the complexes show subnormal magnetic moments. ONNO donor atoms participate in coordination with Cu(II) and Zn(II) complexes exhibiting octahedral geometry. Co(II) and Ni(II) complexes behave differently with ONNO donor atoms showing two types of geometries i.e., octahedral and square planar within the same complex.