Synthesis, spectral, thermal analyses, molecular modeling, and antimicrobial activities of Cu(II)-complexes with 1,3,4-oxadiazole Schiff-base derivatives

Abstract

Seven Cu(II)-complexes with 2-amino-5-substituted aryl-1,3,4-oxadiazole Schiff bases are presented. The donors and possible geometries of the complexes were investigated by elemental and thermal (differential thermal analysis and thermogravimetric analysis) analyses, molar conductance, magnetic moments, IR, ¹H-NMR, ESR, UV-Vis, and mass spectra. The ligands are bidentate, coordinating through the nitrogen of azomethine and the nearest nitrogen to it. The results are supported by 3-D molecular modeling of 2 using CS Chem 3-D Ultra Molecular Modeling and Analysis Program. The investigated complexes have been screened for in-vitro antibacterial (Escherichia coli and Staphylococcus aureus) and antifungal (Aspergillus flavus and Candida albicans) activities. The qualitative and quantitative antimicrobial activities prove that the complexes are very active against the tested microorganisms.

Keywords:

• Cu(II)-complexes
• Oxadiazole Schiff bases
• Molecular modeling
• Antimicrobial activity

Acknowledgments

The authors thank Dr Mohamed El-Zarie (Gakushuin University, Japan) for assistance in measuring ¹H-NMR and mass spectra carried out in this work.