Synthesis and spectral studies of transition metal complexes of some heterocyclic hydrazones derived from 4,6-diacetylresorcinol

Abstract

Two new hydrazone ligands, H2L1 and H2L2, were synthesized by the condensation of 4,6-diacetylresorcinol with 3-hydrazino-5,6-diphenyl-1,2,4-triazine and isatin monohydrazone, respectively. Reactions of the ligands with several copper(II), nickel(II) and cobalt(II) salts in absence and presence of secondary ligands yielded new binary and ternary complexes. The ligands and their complexes were characterized by elemental and thermal analyses, IR, electronic, 1H NMR, ESR and mass spectra as well as conductivity and magnetic susceptibility measurements. Based on the analytical and spectral studies, it was concluded that the coordination sites are phenolic oxygen, azomethine nitrogen and triazinic nitrogen (H2L1 ligand) or isatinic oxygen (H2L2 ligand). The metal complexes exhibited different geometrical arrangements such as octahedral, square planar and tetrahedral arrangements. The ligands and some complexes showed antimicrobial activity against selected kinds of bacteria, yeast and fungi.