Synthesis and structural characterization of asymmetric mononuclear ruthenium (II) complexes derived from 2-(1,2,3-thiadiazol-4-yl)pyridine and azoimine ligands

Five mononuclear ruthenium complexes of the general type trans-[RuII(L)(Azo)Cl2] {(Azo = C6H5NNC(COCH3)NC6H4Y, Y = H (1), CH3 (2), OCH3 (3), Cl (4), Br (5)} and L is 2-(1,2,3-thiadiazol-4-yl)pyridine have been synthesized and their structures investigated by elemental analyses, spectroscopic (IR, UV/–Vis, and NMR) and electrochemical (cyclic voltammetry) techniques. In addition, complex (3) has been further characterized by X-ray diffraction analysis. The absorption spectrum of 3 in acetonitrile has been modeled by time-dependent density functional theory (TD-DFT) using mixed basis set, LanL2DZ/6–-31 + g(d,p), in acetonitrile as a solvent.