Synthesis, X-ray structure, spectroscopic, DFT study and catalytic activity of cis-[RuCl2(L)(EPh3)] complexes (E = P, As, Sb; L = NN′N″ tridentate azoimine-quinoline ligands)

Abstract

Abstract New of complexes of formula cis-[RuCl2(L)(PPh3)] (C1–C5) where L = XC6H4N NC(COCH3) NC9H6N, X = H, L1 (C1); CH3, L2 (C2); Br, L3 (C3); CN, L4 (C4), F, L5 (C5)} and cis-[RuCl2(L1)(EPh3)] where E = As (C6); E = Sb (C7) have been synthesized by refluxing [RuCl2(EPh3)3 ] and L in a mixture of (5:1) chloroform/ethanol solution. The complexes have been characterized by the spectroscopic techniques (IR, NMR and UV–Vis) and geometries have been confirmed by X-ray crystal structures of cis-[RuCl2(L3)(PPh3)] (C3). The electronic structure, redox and absorption properties of the complexes have been explained based on DFT and TDDFT results. Cyclic voltammetric studies show one reversible Ru(III)/Ru(II) oxidation couple and two successive one electron reductions leading to the formation of L(0/−1) and L(−1/−2), respectively. The complexes cis-[RuCl2(L)(EPh3)](C1–C7) catalyze the transfer hydrogenation of acetophenone in 2-propanol at 86 °C and in the presence NaOCH3.