Novel binuclear Cu(II) complexes combining a semicarbazone Schiff base with distinct bridging ligands: Structure and antimicrobial activity

The Schiff base methyl 2-pyridyl ketone semicarbazone (HL) was prepared from the condensation of methyl 2-pyridyl ketone and semicarbazide, and used in the synthesis of a series of novel binuclear Cu(II) complexes with three distinct bridging ligands: [Cu(L)(μ1,1-N3)]2 (1), [Cu(L)(μS,N-SCN)]2 (2) and [Cu(L)(Cl)]2 (3). The compounds were characterized by elemental analysis, IR and UV–Vis spectroscopy, and their solid-state structures have been established by single-crystal X-ray diffraction revealing the first binuclear complexes with the HL ligand. Supramolecular interactions invoving the adjacent complexes were studied in detail. The antimicrobial activity of HL and the complexes 1–3 was further investigated against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Erwinia carotovora and fungals Candida kefyr, Candida krusei and Aspergillus niger, with the complex 3 demonstrating enhanced activity relatively to the free ligand and remaining complexes.

The Schiff base methyl 2-pyridyl ketone semicarbazone (HL) was used in the synthesis of a series of unprecedented binuclear Cu(II) complexes with three distinct bridging ligands: [Cu(L)(μ1,1-N3)]2 (1), [Cu(L)(μS,N-SCN)]2 (2) and [Cu(L)(Cl)]2 (3). Their solid-state structures have been established by single-crystal X-ray diffraction revealing the first binuclear complexes with the HL ligand. The antimicrobial activity of HL and the complexes 1–3 was further investigated against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Erwinia carotovora and fungals Candida kefyr, Candida krusei and Aspergillus niger.Figure optionsDownload as PowerPoint slide