Synthesis, crystal structure, DNA binding and cleavage studies of copper(II) complexes with isoxazole Schiff bases. (14th December 2015) - Pradeep Kumar, Marri
Graphical abstract: Few of the ligands (Schiff bases) and their Cu(II) complexes are characterized by single crystal X-ray diffraction analysis. And we have also done DNA interaction studies of all Cu(II) complexes by using CT-DNA for binding and supercoiled pBR322 DNA for cleavage studies. Abstract: Three novel binary copper(II) complexes1 [Cu(L 1 )2 ], 2 [Cu(L 2 )2 ] and3 [Cu(L 3 )2 ] where, L 1 (1-((E)-(3, 5-dimethylisoxazol-4-ylimino)methyl)naphthalen-2-ol, C16 H14 N2 O2 ), L 2 (2-((E)-(3, 5-dimethylisoxazol-4-ylimino)methyl)-4-methoxyphenol, C13 H14 N2 O3 ) and L 3 (2-((E)-(3, 5-dimethylisoxazol-4-ylimino)methyl)-4-bromophenol, C12 H11 BrN2 O2 ) have been synthesized. All Cu(II) complexes have been characterized by elemental analysis, FT-IR, ESI mass, UV–Vis, ESR, TG-DTA, magnetic moments and single crystal X-ray diffraction studies. Based on spectral studies square planar geometry is assigned for all Cu(II) complexes. Ligand L 1, [Cu(L 1 )2 ] and [Cu(L 2 )2 ] are crystallized and found to be triclinic, orthorhombic and monoclinic crystal systems respectively. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activity and antifungal activity by paper disc method. It is observed that all Cu(II) complexes showed more activity than corresponding Schiff bases. DNA binding and cleavage studies of Cu(II) complexes have also been investigated. It is observed an intercalation mode of binding with CT-DNA and cleavage of supercoiled pBR322 DNA in the presence of H2 O2 and UV light.