Synthesis, structural characterization and microbial activities of mixed ligand copper(II) complexes of 2,2′-bipyridine and acetylacetonate

Two new mixed ligand complexes of copper(II) with acetylacetonate (acac) and 2,2′-bipyridine (bpy) belonging to the class of cytotoxic and antineoplastic compounds known as CASIOPEINAS® have been synthesized and characterized on the basis of analytical and spectroscopic data. Molecular structures of the complexes, [Cu(acac)(bpy)Cl][Cu(acac)(bpy)(H2O]Cl.H2O and [Cu(acac)(bpy)Br]H2O, were established by single crystal X-ray study. The Cu(II) ion in both the complexes exhibited square pyramidal geometry with acac and bpy in the equatorial plane and halide/water in the axial position. Interestingly, for the complex with chloride anion, two types of complexes with chloride and water at the axial positions were derived from the same reaction and co-crystallized in the asymmetric unit with strong intermolecular interactions. Microbial property of these two complexes as antibacterial and antifungal agents has been investigated and some of the results are comparable to that of the standard drugs such as E. coli, P. aeruginosa, S. aureus, S. pyogenes, A. niger and C. albicans, used in this study.

Graphical abstractTwo Cu(II) complexes belonging to the class of cytotoxic and antineoplastic compounds known as CASIOPEINAS® have been synthesized and structurally characterized, their microbial activity against standard drugs were studied and the results are encouraging.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Mixed ligand complexes of Cu(II) have been synthesized following a unique synthetic methodology. ► These complexes are known under the trade name CASIOPEINAS®. ► They were characterized crystallographically. ► Two penta coordinated complexes with chloride and water at the axial positions are co-crystallized. ► Antibacterial and antifungal property of these complexes are comparable to some standard drugs.