Sulfonylbenzimidazoles and their copper complexes have tremendous applications in drug development. In the present work, bis(2-hydroxylbenzoato-kappa O-2,O ')bis(2-methyl-1-(toluene-4-sulfonyl)-1H-benzimidazole) copper(II) complex [Cu(L-1)(L-2)] has been synthesized and structurally characterized by Fourier-transformed infrared spectroscopy (FTIR) and single-crystal X-ray diffraction (XRD). The complex formed a distorted octahedral geometry with the benzimidazole ligands occupying the axial position and the hydroxylbenzoato ligands in the equatorial positions. The latter ligands coordinated in an isobidentate manner with a Cu-O-deprotenated bond length of 1.955(18) angstrom and a long range Cu-O-carbonyl of 2.574(2) angstrom. An excellent correlation was found between bond lengths and bond angles obtained experimentally from single-crystal XRD analysis and that obtained from density functional theory. Electrochemical behavior of [Cu(L-1)(L-2)] has been probed by cyclic voltammetry (CV). CV studies revealed that it undergoes one-electron reduction followed by one-electron oxidation process. In vitro tyrosinase inhibitory activity of the complex was evaluated and it was observed that it exhibited good inhibitory potential with IC50 value 56.8 +/- 11.4 mu M. Complex-DNA-interaction studies were performed by CV, electronic and florescence spectroscopic titrations and it has been inferred that the [Cu(L-1)(L-2)] binds with DNA through intercalation and the value of binding constant was 3.6 x 10(4) M-1.

Sulfonylbenzimidazoles and their copper complexes have tremendous applications in drug development. In the present work, bis(2-hydroxylbenzoato-kappa O-2,O ')bis(2-methyl-1-(toluene-4-sulfonyl)-1H-benzimidazole) copper(II) complex [Cu(L-1)(L-2)] has been synthesized and structurally characterized by Fourier-transformed infrared spectroscopy (FTIR) and single-crystal X-ray diffraction (XRD). The complex formed a distorted octahedral geometry with the benzimidazole ligands occupying the axial position and the hydroxylbenzoato ligands in the equatorial positions. The latter ligands coordinated in an isobidentate manner with a Cu-O-deprotenated bond length of 1.955(18) angstrom and a long range Cu-O-carbonyl of 2.574(2) angstrom. An excellent correlation was found between bond lengths and bond angles obtained experimentally from single-crystal XRD analysis and that obtained from density functional theory. Electrochemical behavior of [Cu(L-1)(L-2)] has been probed by cyclic voltammetry (CV). CV studies revealed that it undergoes one-electron reduction followed by one-electron oxidation process. In vitro tyrosinase inhibitory activity of the complex was evaluated and it was observed that it exhibited good inhibitory potential with IC50 value 56.8 +/- 11.4 mu M. Complex-DNA-interaction studies were performed by CV, electronic and florescence spectroscopic titrations and it has been inferred that the [Cu(L-1)(L-2)] binds with DNA through intercalation and the value of binding constant was 3.6 x 10(4) M-1.