Synthesis and characterization of some Chromium(III) complexes of dibasic tridentate hydrazone schiff base ligands

Coordination complexes of Cr(III)with four tridentate Schiff base ligands viz. N-(2-hydroxy-1-naphthaldehyde)- -(4-nitrobenzoyl)hydrazone(HNNH = H2L 1 ), N-(2-hydroxy-4-methoxybenzaldehyde)- -(2-furoyl) hydrazone (HMFH = H2L 2 ), N-(2-hydroxyacetophenone)- -(2-theonyl) hydrazone (HATH = H2L 3 ) and N-(2- hydroxy-5-methylacetophenone)- -(3-toloyl) hydrazone (HMAT = H2L 4 ) have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, thermogravimetric analysis and spectral (IR, electronic, NMR) measurements. IR spectra indicates that the ligand behave as dibasic tridentate ligand in a chelate coordinating to Cr(III) ion through ketonic oxygen, azomethine nitrogen and by both enolic and phenolic protons (except in H2L 1 by naphtholic oxygen atom) via double deprotonation of ligands. The magnetic and spectral data indicate chelate in octahedral environment and analytical data suggest 1:1 stoichiometries for the complexes