Synthesis, characterization and antimicrobial activity of copper(II) complexes with hydrazone derived from 3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carbaldehyde

Abstract Pyridoxal isonicotinoyl hydrazone ( HL ) and its copper(II) complexes: [CuLCl(H 2 O) 2 ] ( 1 ), [CuL(OAc)](H 2 O) ( 2 ), [CuL(OAcac)] ( 3 ), [CuL(NO 3 )](H 2 O) ( 4 ), [CuL 2 ](H 2 O) ( 5 ) were synthesized and characterized. The ligand has been obtained by condensation of 3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carbaldehyde (pyridoxal) hydrochloride with isonicotinoyl hydrazide. The characterization of the formed compounds was done by 1 H NMR, 13 C NMR, UV–Vis, IR and EPR spectroscopy as well by thermal studies and elemental analysis. The crystal structure of HL has been determined by single crystal X-ray diffraction studies. The microbiological effect of the ligand and all five complexes against both Gram-positive and Gram-negative strains, Staphylococcus aureus ATTC 6538, Bacillus cereus ATCC 14579, Escherichia coli W3110 and Pseudomonas aeruginosa ATCC 9027 was tested.