Complexes of cis-bis(triphenylphosphine)ruthenium(II) with N,S-donor thiobenzhydrazones of polycyclic aromatic aldehydes: Synthesis, properties and structures
作者:Koppanathi Nagaraju、Samudranil Pal
DOI:10.1016/j.ica.2014.01.002
日期:2014.3
Reactions of [Ru(PPh3)(3)Cl-2], H2Ln (polycyclic aromatic aldehyde thiobenzhydrazones ArCH=NNHC(=S) Ph, n = 1-4 for Ar = 1-naphthalenyl, 9-anthracenyl, 9- phenanthryl and 1-pyrenyl, respectively) and NaOAc in 1:2:2 mol ratio in methanol produces ruthenium(II) complexes of formula cis-[Ru(PPh3)(2)(HLn)(2)] (1-4) in 80% yields. Microanalysis (CHN), magnetic susceptibility, solution conductivity, spectroscopic (IR, UV-Vis, NMR and fluorescence) and cyclic voltammetric measurements have been used for the characterization of 1-4. The complexes are non-electrolytic and diamagnetic. In the electronic spectra, the complexes display multiple absorptions within 505-245 nm due to metal-to-ligand charge transfer and ligand centred transitions. The emission spectral features of 1-4 indicate ligand centred emissive states. Molecular structures of 3 and 4 have been determined by X-ray crystallography. In each of 3 and 4, two thioamidate- N,S coordinating (HLn) and two mutually cis oriented PPh3 molecules assemble a distorted octahedral N2S2P2 coordination sphere around the metal centre. Cyclic voltammograms of 1-4 show an oxidation response within E-1/2 = 0.76-0.86 V (Delta E-p = 90-100 mV) versus Ag/AgCl. (c) 2014 Elsevier B.V. All rights reserved.