Half-sandwich Ruthenium(II) arene complexes bearing the azo-azomethine ligands: Electrochemical, computational, antiproliferative and antioxidant properties

Abstract

Three novel azo-azomethine ligands have been synthesized in an accomplished one-pot synthesis protocol. The mononuclear Ru(II) complexes of these azo-azomethine dyes were prepared and characterized by the combination of elemental analyses, IR, UV-Visible spectroscopy and H-1-C-13 NMR spectra. Solid state structures of 3, 4 and 7 were determined by single crystal X-ray diffraction studies. The electrochemical and photoluminescence properties of the compounds were studied. The 1931 CIE (x, y) chromaticity coordinates of the ligands and their metal complexes were investigated and the x, y values of the compounds were found to be close to the National Television Standard Committee (NTSC) standard. Quantum chemical calculation of related ligands and complexes are performed at B3LYP/6-31G(d, p) and B3LYP/6-31G(d, p) (LANL2DZ) level in vacuum. In addition, the azo-azomethine ligands and their Ru(II) complexes were evaluated for both their in-vitro antibacterial activity by the disc diffusion method and antioxidant properties using ferric reduction power, DPPH free radical, and ABTS cation radical scavenging activities as in vitro. Radical scavenging activities of compounds 5-7 were found higher than BHT, BHA, and Trolox used as positive controls. Compounds 2-4 antioxidant capacities were lower than the positive controls. Finally, the new azoazomethine dyes and their Ru(II) complexes were investigated for their in vitro antiproliferative activities against non-small cell lung cancer cells (H2126), prostate adenocarcinoma cells (PC3) and breast cancer cells (MCF7) in vitro. Cell proliferation test were performed as dose-dependent assays at 200 mu M. The new azo-azomethine ligands and their Ru(II) complexes have shown anticancer activity on the studied cell lines after 24 h exposure to 200 mu M compounds. However, the activities of the compounds are much lower than 5-Fu. (C) 2018 Elsevier B.V. All rights reserved.