Octahedral copper(II) carboxylate complex: synthesis, structural description, DNA-binding and anti-bacterial studies

Abstract

<p>Self-assembly of CuSO₄, <i>para</i>-methyl-2-phenyl acetate and 1,10-phenanthroline afforded good-quality crystalline complex in quantitative yield. The complex was characterized by FTIR and UV-visible spectroscopy, electrochemistry, and powder and single-crystal XRD studies. Its structure was found to possess axially elongated octahedral symmetry with CuO₄N₂ chromophore. Its purity was assessed by powder XRD spectrum. Absorption study yielded a broad band corresponding to ²E_g→²T_2 g transition. Electrochemical solution study indicated diffusion-controlled irreversible electron transfer process corresponding to Cu(II)/Cu(I) redox couple with diffusion coefficient = 7.89(±0.1)×10⁻⁹ cm²s⁻¹. Results of spectroscopic techniques support each other. Complex exhibited excellent DNA-binding ability through UV-visible spectroscopy and cyclic voltammetry yielding <i>K</i>_<i>b</i> values 1.399 × 10⁴ M⁻¹ and 5.81 × 10³ M⁻¹, respectively. The complex exhibited significant activity against bacterial strains <i>Escherichia coli</i>, <i>Micrococcus luteus</i> and <i>Staphylococcus aureus</i> and good activity against <i>Bacillus subtilis</i>. These preliminary studies impart good biological relevance on the synthesized complex.</p