Synthesis, Characterization, DNA binding and Microbial Activity of Cobalt (III) Complexes of Mixed Ligands, Hydroxamic Acid and 1,10-Phenanthroline

Abstract

New Co(III) complexes of mixed ligands, hydroxamic acid (L1 = AHA (acetohydroxamic acid), L2 = BHA (benzohydroxamic acid) and L3 = OHA (oxalohydroxamic acid) and 1, 10-phenanthroline (phen) were synthesized and characterized by NMR, IR, UV-visible, mass spectrometer, and elemental analysis. In the complexes, [Co(phen)₂L]ClO₄ (L = L1, L2, L3), the metal ion is coordinated by six atoms, two oxygen atoms from hydroxamic acid and 4N atoms from co-ligand 1, 10-phenanthroline to form octahedral Co(III) complexes. The interaction of these complexes with calf thymus DNA (CT-DNA) has been investigated by absorption spectroscopy measurement. The DNA-binding constants for complexes 1, 2, 3 are 2.47 x 10⁶ M^-1, 4.02 x 10⁶ M^-1, 2.23 x 10⁶ M^-1 respectively. Detailed analysis shows that these complexes bind with DNA through interaction binding. And the study of microbial activity against Gram positive and Gram negative bacteria.

Keywords: DNA binding, hydroxamic acid, cobalt complexes, 1, 10-phenanthroline, microbial activity.