A binary copper(II) complex having stepped polymeric structure: Synthesis, characterization, DNA-binding and anti-fungal studies

Abstract

A rarely found polymeric complex of copper(II) was obtained in the reaction of 2-(4-methylphenyl)acetate and copper sulfate and crystallized in quantitative yield. The complex was characterized using FT-IR, electron spin resonance, absorption spectroscopy, electrochemistry and powder and single crystal XRD studies. The structure was found to consist of interconnected paddlewheel units without an intervening ligand resulting in a stepped polymeric arrangement of the structure. The purity of the sample was judged from powder XRD data while ESR spectroscopy indicated a weak signal between 3000 and 4000 G values, indicating the presence of Cu(II) in the complex. Electrochemistry revealed an irreversible, predominantly diffusion controlled CuIICuII/CuIICuI process with a D0 value calculated to be 3.032?10-8 cm2 s-1. The complex was screened for its DNA-binding ability through cyclic voltammetry, absorption and florescence spectroscopy and viscometry; the former two yielding Kb values of 3.34?103 and 6.90?103 M-1, respectively. The complex exhibited significant activity against fungal strain Mucor piriformis, moderate activity against Aspergillus niger and slight activity against Helminthosporium solani. These preliminary findings revealed the excellent biological potential of the synthesized complex.