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51.
Carlos A. Martinez Eric Keller Renzo Meijer Gerard Metselaar Gerlof Kruithof Curtis Moore Pei-Pei Kung 《Tetrahedron: Asymmetry》2010,21(19):2408-2412
An efficient four-step biotransformation-mediated synthesis of (1S)-1-(2,6-dichloro-3-fluorophenyl)ethanol in enantiomerically pure form is described. This compound is a key intermediate required for the preparation of PF-2341066, a potent inhibitor of c-Met/ALK that is currently in clinical development. The described synthesis was used to manufacture 6 kg of the title compound and can also be employed to produce the corresponding (1R)-enantiomer. 相似文献
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53.
Niobium and tantalum carbide clusters have been isolated in the gas phase and irradiated with intense tunable infrared (IR) light. Stable neutral clusters are selectively ionized and subsequently detected in a mass spectrometer. By tuning the IR frequency, infrared multiphoton absorption spectra are obtained for a whole range of clusters. These mass-selective IR spectra lead to insights into the structures of small niobium and tantalum carbide clusters and nanocrystals. 相似文献
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55.
J.J. Neve C.F.J. de Meijer F.A.P. Blom 《Journal of Physics and Chemistry of Solids》1981,42(11):975-980
Shubnikov-de Haas oscillations in the transverse magnetoresistance of single-crystalline n-type CdSnAs2 have been recorded at temperatures between 2 and 25 K in magnetic fields up to 5T. The electron concentration of the samples ranged from 2 × 1017 to 2 × 1018 cm?3. The angular dependences of the oscillation periods and cyclotron effective masses showed that the conduction band exhibits an energy dependent anisotropy, obeying the Kildal band structure model. For the low-temperature values of the band parameters we found: a band gap Eg = 0.30 eV, a spin-orbit splitting Δ = 0.50 eV, a crystal field splitting parameter δ = ?0.09 eV, and an interband matrix element P = 8.5 × 10?8eV cm. This simple four-level model was found to be not adequate to describe quantitatively the observed electronic effective g-factor for a sample with low electron concentration. 相似文献
56.
The complex 1-methylally(cyclooctatetraene)titanium has been prepared by the reaction of cyclooctatetraenetitanium chloride and 1-methylallylmagnesium bromide. The IR spectrum shows the vibrations of the h8-C8H8 ligand and of a π-bonded methylallyl group. The mass spectrum is also discussed. 相似文献
57.
Since the thermodynamic properties of cerous magnesium nitrate play such an important role in low temperature physics we computed the influence of all variations still possible under the given set of known data: Small variation in the lattice structure, in particular the displacement of the center plane, small variations of the g-factor and the combination thereof. 相似文献
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59.
Fielicke A von Helden G Meijer G Simard B Rayner DM 《The journal of physical chemistry. B》2005,109(50):23935-23940
We report the vibrational spectra of the carbonyl complexes of anionic gold clusters in the range of the CO stretching frequency as measured in the gas phase using IR multiple photon dissociation spectroscopy. The investigated complexes contain between 3 and 14 Au atoms and up to 7 CO ligands. Special attention is given to the complexes that exhibit saturation CO coverage as well as to the monocarbonyl species. In conjunction with data from the corresponding cationic complexes we quantify how the CO stretching frequency varies with the charge state of the gold cluster. Our results provide a size- and charge-dependent basis to interpret values of the CO stretching frequency measured for CO on deposited gold clusters in terms of the charge states of the clusters. 相似文献