摘要 : The reaction of P,S-chelating diphosphane ligands [bis(2-di- phenylphosphanylphenyl)ether monosulfide] (a) and [9,9-di-methyl-4,5- bis(diphenylphosphanyl)xanthene monosulfide] (b) with [Ru(CO)_2Cl _2]_n in a 1:1 molar ratio afford... 展开 The reaction of P,S-chelating diphosphane ligands [bis(2-di- phenylphosphanylphenyl)ether monosulfide] (a) and [9,9-di-methyl-4,5- bis(diphenylphosphanyl)xanthene monosulfide] (b) with [Ru(CO)_2Cl _2]_n in a 1:1 molar ratio affords two new ruthenium(II) complexes of the type [Ru(CO)_2Cl_2(PnS)] (1a, 1b), where P∩S = a, b. The compounds are characterized by elemental analyses, mass spectrometry, thermal studies, and IR and NMR spectroscopy, together with single-crystal X-ray structure determination of bis(2-diphenylphosphanylphenyl) ether (DPEphos), a, 1a, and 1b. The ruthenium atom in both 1a and 1b occupies the center of a slightly distorted octahedral environment formed by a P atom, an S atom, two Cl atoms, and two CO groups. The crystal structures of a and la highlights an interesting feature, in which the P(2)-P(1)-S(1) spatial angle (ca. 174.7°) in free ligand a is reduced to around 46° upon complexation, which indicates a very high flexibility of the angle. Complex la also exhibits some hemilabile behavior in solution because of its flexible ligand back-bone, while ligand b in complex 1b remains rigid in solution. Complexes 1a and 1b are thermally stable up to about 300 °C and show high catalytic activities in the transfer hydrogenation of aldehydes and ketones to the corresponding alcohols. The highest conversion (about 99%) with the corresponding TOP value of about 1000 h~(-1) was obtained for 1a in the case of benzaldehyde. The catalytic efficiency of la is found to be much higher than 1b, which might result from the hemilabile behavior of ligand a. 收起