Vibrational and H-NMR spectroscopic studies on di-μ-chlorobis(1,5-cyclooctadiene) of iridium(I) and rhodium (I) complexes have been carried out. In addition, the two D2h and D2 structures for both complexes have been...Vibrational and H-NMR spectroscopic studies on di-μ-chlorobis(1,5-cyclooctadiene) of iridium(I) and rhodium (I) complexes have been carried out. In addition, the two D2h and D2 structures for both complexes have been fully optimized. It was expected from the single-molecule vapor-phase density functional theory (DFT) calculation that the D2 structure is more stable by 5 - 6 kcal/mol. While spectroscopic analysis study confirms that in the solid phase, the two complexes retain the higher D2h symmetry. The vibrational wavenumbers of certain modes associated to free 1,5-cyc- looctadiene were observed to be shifted to lower values upon coordination with rhodium or iridium metals. It was also found theoretically that the metal-olefin interaction is slightly more pronounced for iridium metal.展开更多
The title complex [Fc（OCH3）PS2Ir（cod）] （1, Fc = Fe（η^5-C5H4）（η^5-C5H5）, cod = 1,5-cyclooctadiene） has been prepared and characterized by X-ray diffraction analysis. It crystallizes in monoclinic, space gro...The title complex [Fc（OCH3）PS2Ir（cod）] （1, Fc = Fe（η^5-C5H4）（η^5-C5H5）, cod = 1,5-cyclooctadiene） has been prepared and characterized by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 12.5567（5）, b = 13.5197（5）, c = 11.7833（4） A, β = 99.651（2）°, V = 1972.06（13）A^3, Z = 4, Mr = 611.52, Dc = 2.06 g/cm^3, μ（MoKα） = 7.775 mm^-, F（000） = 1184, S = 1.063, the final R = 0.0199 and wR = 0.0468 for 4063 observed reflections with I 〉 2σ（I） and 227 variables. The molecular structure of 1 shows that the central iridium atom is chelated by the [Fc（OCH3）PS2]-ligand via two sulfur atoms and coordinated by one η^4-cod molecule via four carbon atoms in a distorted octahedral coordination geometry. The average Ir-S and Ir-C bond lengths are 2.3712（8） and 2.122（3） A, respectively.展开更多
Polyethylene glycol （PEG）-stabilized palladium nanoparticles were prepared and applied to the selective hydrogenation of 1,5- cyclooctadiene （1,5-COD） in thermoregulated PEG biphase system, which allows a reaction...Polyethylene glycol （PEG）-stabilized palladium nanoparticles were prepared and applied to the selective hydrogenation of 1,5- cyclooctadiene （1,5-COD） in thermoregulated PEG biphase system, which allows a reaction in a single-phase at a higher temperature followed by a phase split at a lower temperature. Under the optimized reaction conditions, the conversion of 1,5-COD and the selectivity of cyclooctene （COE） were 100 and 98%, respectively. The catalyst could be easily separated from the product by phase separation and reused for 6 times without evident loss in activity and selectivity. 2007 Yan Hua Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
文摘Vibrational and H-NMR spectroscopic studies on di-μ-chlorobis(1,5-cyclooctadiene) of iridium(I) and rhodium (I) complexes have been carried out. In addition, the two D2h and D2 structures for both complexes have been fully optimized. It was expected from the single-molecule vapor-phase density functional theory (DFT) calculation that the D2 structure is more stable by 5 - 6 kcal/mol. While spectroscopic analysis study confirms that in the solid phase, the two complexes retain the higher D2h symmetry. The vibrational wavenumbers of certain modes associated to free 1,5-cyc- looctadiene were observed to be shifted to lower values upon coordination with rhodium or iridium metals. It was also found theoretically that the metal-olefin interaction is slightly more pronounced for iridium metal.
基金supported by the National Natural Science Foundation of China (20771003)
文摘The title complex [Fc（OCH3）PS2Ir（cod）] （1, Fc = Fe（η^5-C5H4）（η^5-C5H5）, cod = 1,5-cyclooctadiene） has been prepared and characterized by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 12.5567（5）, b = 13.5197（5）, c = 11.7833（4） A, β = 99.651（2）°, V = 1972.06（13）A^3, Z = 4, Mr = 611.52, Dc = 2.06 g/cm^3, μ（MoKα） = 7.775 mm^-, F（000） = 1184, S = 1.063, the final R = 0.0199 and wR = 0.0468 for 4063 observed reflections with I 〉 2σ（I） and 227 variables. The molecular structure of 1 shows that the central iridium atom is chelated by the [Fc（OCH3）PS2]-ligand via two sulfur atoms and coordinated by one η^4-cod molecule via four carbon atoms in a distorted octahedral coordination geometry. The average Ir-S and Ir-C bond lengths are 2.3712（8） and 2.122（3） A, respectively.
基金Financial support from the National Natural Science Foundation of China （No. 20573015） is gratefully acknowledged.
文摘Polyethylene glycol （PEG）-stabilized palladium nanoparticles were prepared and applied to the selective hydrogenation of 1,5- cyclooctadiene （1,5-COD） in thermoregulated PEG biphase system, which allows a reaction in a single-phase at a higher temperature followed by a phase split at a lower temperature. Under the optimized reaction conditions, the conversion of 1,5-COD and the selectivity of cyclooctene （COE） were 100 and 98%, respectively. The catalyst could be easily separated from the product by phase separation and reused for 6 times without evident loss in activity and selectivity. 2007 Yan Hua Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
