Synthesis, characterization and DNA-binding studies of mono and heterobimetallic complexes Cu[single bond]Sn sub(2)/Zn[single bond]Sn sub(2) and their DNA cleavage activity

• Published in: Journal of molecular structure 2010-02, Vol.965 (1-3), p.14-22
• Main Authors: Arjmand, Farukh, Sayeed, Fatima
• Format: Article
• Language: English
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2009.11.025

Heterobimetallic complexes C sub(6)H sub(2)4N sub(4)O sub(6)CuSn sub(2)Cl sub(6) 3, C sub(6)H sub(2)4N sub(4)O sub(6)ZnSn sub(2)Cl sub(6) 4 have been synthesized from their monometallic analogs C sub(6)H sub(16)N sub(4)O sub(2)CuCl sub(2) 1, C sub(6)H sub(16)N sub(4)O sub(2)ZnCl sub(2) 2, and were characterized by various spectroscopic and analytical methods. The complexes 1-4 reveal an octahedral geometry for both central metal ions Cu/Zn as well as for Sn metal ion. The interaction of complexes 1-4 with CT-DNA, were investigated by using absorption, emission, cyclic voltammetry, viscometry and DNA cleavage studies. The emission quenching of 3 and 4 by [Fe(CN) sub(6)][super]4- depressed greatly when bound to CT-DNA. The results of spectroscopic, viscometric and cyclic voltammetry of complexes 3 and 4 revealed electrostatic mode of binding of the complexes with CT-DNA. These results revealed that 4 bind more avidly in comparison to 3 with CT-DNA. Gel electrophoresis of DNA with complexes 3 and 4 demonstrated that the complexes exhibit excellent cleavage activity under physiological conditions.