Two new binuclear copper complexes, [Cu(2)(oxpn)(bpy)(pic)(H(2)O)](pic) (1) and [Cu(2)(oxpn)(Me(2)bpy)(pic)](pic) (2) [H(2)oxpn=N,N'-bis(3-aminopropyl)oxamide; Hpic=2,4,6-trinitrophenol; bpy=2,2'-bipyridine; Me(2)bpy=4,4'-dimethyl-2,2'-bipyridine], have been synthesized and characterized by elemental analyses, conductivity measurements, IR, UV-visible spectroscopy and single crystal X-ray analyses. Both complexes have similar molecular structures. In complex 1, the central two Cu(II) atoms are bridged by cis-oxpn(2-) with the Cu1-Cu2 separation of 5.221A and the polyhedron of each copper atom is a square-pyramid. Similarly, complex 2 is a cis-oxpn(2-)-bridged binuclear complex with the Cu1-Cu2 separation of 5.196A. Cu1(II) central atom situated in a tetrahedral geometry is four-coordinated and Cu(II) atom situated in a square-pyramidal geometry is five-coordinated. Hydrogen bonding interactions and pi-pi stacking interactions link the binuclear copper complex 1 or 2 into a 2D infinite network. The antibacterial assays indicate that the two complexes showed better activities than their ligands. The interactions of the two binuclear complexes with herring sperm DNA (HS-DNA) have been studied by UV absorption titration, fluorescence titration and viscosity measurements. The results suggest that the two binuclear complexes bind to HS-DNA via an intercalative mode.
