Synthesis, Structural Characterization, and Antibacterial Activity of Cu(II) and Zn(II) Complexes With Tetradentate Schiff Bases

Abstract

Biological activity study on Cu(II) and Zn(II) complexes is a challenging issue because of the activity of ligands could be modulated by complexation. A new dinuclear copper(II) complex, [Cu₂(L¹)₂]·2CH₃OH (1), and a new mononuclear zinc(II) complex, [ZnL²(CH₃OH)] (2), where L¹ is the dianionic form of the bis-Schiff base N,N′-bis(2-hydroxy-5-methoxybenzylidene)-1,2-ethanediamine (H₂L¹), and L² is the dianionic form of N,N′-bis(5-fluoro-2-hydroxybenzylidene)-1,2-ethanediamine (H₂L²), have been synthesized and characterized by single-crystal X-ray diffraction. X-ray analysis indicates that the metal atoms in the complexes are in square pyramidal coordination. Antibacterial activity of the complexes against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Candida albicans strains was studied and compared with that of the free Schiff bases.

Keywords:

• Schiff base
• Cu(II) complex
• Zn(II) complex
• crystal structure
• antibacterial activity

Funding

The work was supported by the Guangdong Pharmaceutical University Young Teachers' Fund and the Ten Hundred Thousand Project of the Bureau of Education of Guangdong Province, P. R. China.

Supplementary Material

CCDC 940554 (1) and 972038 (2) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: [phone]; or e-mail: [email protected].