Oxidation of Ru-bound thiolate thioether and its NS₄-ligand containing thiolate and thioether sulfur donors: synthesis, characterization, and X-ray structures

Abstract

A ruthenium complex [Ru(H 2 O){Et 2 NpyS 4 (O 3 ) 2 }] Á (4) containing sulfinates, sulfenates S-donors, and water as co-ligand has been synthesized from oxidation of hydrazine complex [Ru(N 2 H 4 )(Et 2 NpyS 4 )] (3) and completely characterized with X-ray structural analysis [Et 2 NpyS À2 4 = 4-(diethylamino)-2,6-bis[(2-mercaptophenyl)thiomethyl]pyridine(2À)]. Complex 4 exhibits distorted octahedral coordination of the ruthenium center and the d [Ru-S sulfinates ] and d [Ru-S sulfenates ] are almost equivalent. The average d [S-O sulfinate ] at 148.0 pm is ca 10 pm longer than the average d [S-O sulfenate ] at 138.0 pm. The sulfinates IR(KBr) bands are located in the range 1132-1113 cm À1 as two band sets, (SO) asym and (SO) sym , whereas the sulfenates show a single absorbance at approximately 882 cm À1 . The lower frequency of the (SO)stretches of the sulfenates as compared to that of their sulfinate rivals indicates a weaker S-O bond in the sulfenates and is consistent with X-ray crystal structure data (vide infra). Oxidation of the dithiol ligand Et 2 NpyS 4 -H 2 (1) under the same condition afforded the disulfide, in this case forming a macrocyclic ligand S,S-Et 2 NpyS 4 (2) as is evidenced by an X-ray crystal structure determination. Thus, the oxidation of 3 involves activation of either the oxygen or thiolate by the ruthenium center.

Therapeutic effect of dithiophenolato chitosan nanocomposites against carbon tetrachloride-induced hepatotoxicity in rats

“…) (Shaban et al 2010). The bisul te can be oxidized by both one-and two-electrons forming sulfur trioxide radical anion (SO 3…”

Curative Role of Dithiophenolato Titanium (IV)-Chitosan Nanocomposite Complex Against Carbon Tetrachloride-Induced Liver Injuries

“…TiO 2 induces the generation of ROS such as O 2 -• and H 2 O 2 , resulting in increasing oxidative stress, lipid peroxidation, membrane damage, and increases the apoptosis of the unwanted cells [30]. Also, the thiol groups in the DBT and DBT-CSNPs are able to oxidize in the presence of H 2 O 2 , forming O-S-O [31] resulting in the reduction of H 2 O 2 and this leads to the non-signi cant elevation in the MDA level compared with CCl 4 . Moreover, the reduction in the antioxidant enzymes may be related to the fact that SOD and GPx are Zn-and selenium-dependent enzymes, respectively.…”

Therapeutic Effect of Dithiophenolato Chitosan Nanocomposites Against Carbon Tetrachloride-induced Hepatotoxicity in Rats

“…et al 2010). The bisul te can be oxidized by both one-and two-electrons forming sulfur trioxide radical anion (SO 3•-) and sulfate (SO4 2-).Then SO 3•reacts with a molecule of oxygen forming an O 2 •and peroxysulfate radical anion (SO 5•-Shaban et al 2010). The results in Fig.3showed that the toxic effects of the reactive metabolites werelower than the useful effects of the antioxidants present in the dithiol groups of DPT and DPT.…”