1021490-40-3Relevant academic research and scientific papers
Transfer hydrogenation of ketones and catalytic oxidation of alcohols with half-sandwich complexes of ruthenium(II) designed using benzene and tridentate (S, N, E) type ligands (E = S, Se, Te)
Singh, Pradhumn,Singh, Ajai K.
experimental part, p. 6433 - 6442 (2011/02/17)
The complexes of composition fac-[(η6-C6H 6)Ru(L)][PF6][X] (1-6; X = PF6 or Cl), formed by reacting 2-MeSC6H4CH=NCH2CH 2E-C6H4-4-R (L1-L3) and 2-MeSC 6H4CH2-NHCH2CH2E-C 6H4-4-R (L4-L6) (where E = S or Se, R = H; E = Te, R = OMe) with [{(η6-C6H6)RuCl(μ-Cl)} 2] and NH4PF6, have been characterized by 1H, 13C{1H}, 77Se{1H}, and 125Te{1H} NMR spectroscopy and X-ray crystallography. The Ru-Se and Ru-Te bond lengths are in the ranges 2.4837(14)-2.4848(14) and 2.6234(6)-2.6333(7) A, respectively. Complexes 1-6 have been found to be efficient catalysts for catalytic oxidation of alcohols with N-methylmorpholine-N-oxide, tBuOOH, NaOCl, and NaIO4 and transfer hydrogenation reaction of ketones with 2-propanol. The TON values are up to 9.9 × 104 and 9.8 × 104 for two catalytic processes, respectively. The oxidation probably involves the formation of intermediate species having Ru(IV)=O. Complexes 1-3 are as efficient as 4-6 for transfer hydrogenation of ketones. In transfer hydrogenation, the mechanism does not appear to be dependent on the availability of hydrogen on nitrogen and probably involves Ru-H bond formation. The catalytic efficiency for both processes follows the order Te > Se > S, which may be due to the presence of a MeO group on Te.
