DNA BINDING AND ANTIBACTERIAL ACTIVITY OF TRANSITION METAL COMPLEXES WITH PREORGANIZED HEXADENTATE LIGAND

A new preorganized ligand, benzil bis [2-(2-amino-ethylamino) ethanol)] (H2BAE) has been synthesized and characterized for the first time. Copper (II) and cobalt (II) complexes of H2BAE have been synthesized and characterized based on molar conductivity data IR, UV-Vis spectroscopy.  The complexes are found to have general formula M(BAE)2 (where, M = Cu (II) and Co (II).  IR spectral data indicate that H2BAE acts as hexadentate ligand. The complexes are 6-coordinate and found to have octahedral structure; the copper complex is investigated using ESR spectroscopy at room temperature (RT) and liquid nitrogen temperature (LNT). The spin Hamiltonian, orbital reduction, and bonding parameters are calculated for the complex. The interactions of these complexes with calf thymus DNA have been investigated using absorption spectrophotometry. Groove binding of complexes to DNA is suggested on the basis of deoxyribonucleic acid (DNA) binding constants and the variations in the absorption spectra of metal complexes in the presence of DNA. The copper complex binds DNA more strongly than cobalt complexes. Metal complexes are screened for their antibacterial activity by using the agar well diffusion method. The complexes inhibit bacteria more strongly than H2BAE ligand.