Synthesis, Spectral Characterization and Biocidal Studies of Copper(II) Complexes of Chromen-2-one-3-carboxy Hydrazide and 2-(Chromen-3'-onyl)-5-(aryl)-1,3,4-oxadiazole Derivatives

Abstract

Copper(II) complexes of chromen-2-one-3-carboxyhydrazide and 2-(chromen-3'-onyl)-5-(aryl)-1,3,4-oxadiazole derivatives have been synthesized. The structural features have been determined from their microanalytical, magnetic susceptibility, molar conductance, IR, UV Vis, ¹H NMR and ESR spectral data. All the Cu(II) complexes exhibit the composition Cu(Ln)₂X₂; where L1= chromen-2-one-3-carboxy hydrazide, L2 = 2-(chromen-3'-onyl)-5-(2ʺ-hydroxy phenyl)-1,3,4-oxadiazole, L3 = 2-(chromen-3'-onyl)-5-(4ʺ-nitrophenyl)-1,3,4 -oxadiazole and L4 = 2-(chromen-3'-onyl)-5-(4ʺ-chlorophenyl)-1,3,4-oxadiazole; X = Cl^-, Br^-, NO₃^-, CH₃COO^-, ClO₄^- and CNS^-. The N, O donor ligands act as a bidentate ligand in all the complexes. Distorted octahedral geometry for all the Cu(II) complexes is proposed. Molecular modeling studies have been made for the rapid structure building, geometry optimization and molecular display. These complexes show the conductance values, supporting their non-electrolytic nature. The monomeric nature of the complexes was confirmed from their magnetic susceptibility values. These complexes have been screened for their antimicrobial activities against some bacterial species like S.aureus, E.coli, Pseudomonas aeruginosa and few fungal strains C.albicans and Cryptococcus neoformans.