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61.
Sodium, potassium, rubidium, caesium, ammonium and tetramethylammonium tetraphenylborates were studied by both positive and negative ion electrospray mass spectrometry. An affinity order of Cs+ > Rb+ > K+ ~ Na+ was obtained. The results obtained were compared with both calculations and solid-state structures, where available. The previously reported high affinity of caesium for tetraphenylborate concluded from NMR experiments was confirmed for the gas phase. The affinity does not appear to result from steric effects and a cation–pi interaction seems likely. In the positive ion mode, a unique acetonitrile complex of NaBPh4 was observed. 相似文献
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63.
Vincent J. Kalish Robert L. Shone Steven W. Kramer Paul W. Collins Kevin A. Babiak Kathleen T. McLaughlin 《合成通讯》2013,43(11):1641-1645
Hydrozirconation-iodination of a terminal acetylene followed by lithium-iodide exchange and finally dilithio cyanocuprate mediated conjugate addition to an appropriate cyclopentenone is reported as an efficient method for the synthesis of prostaglandin analogues. 相似文献
64.
Philipp Bissinger Prof. Dr. Holger Braunschweig Dr. Alexander Damme Dr. Rian D. Dewhurst Dr. Katharina Kraft Thomas Kramer Dr. Krzysztof Radacki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(40):13402-13407
The synthesis of base‐stabilized boryl and borylene complexes is reported. An N‐heterocyclic carbene (NHC)‐stabilized iron–dihydroboryl complex was prepared by two different routes including methane liberation and salt elimination. A range of base‐stabilized iron–dichloroboryl complexes was prepared by addition of Lewis bases to boryl complexes. Base‐stabilized, cationic monochloroborylene complexes were synthesized from these boryl complexes by halide abstraction by using weakly coordinating anions. 相似文献
65.
Jiang X Arrington J Benmokhtar F Camsonne A Chen JP Choi S Chudakov E Cusanno F Deur A Dutta D Garibaldi F Gaskell D Gayou O Gilman R Glashauser C Hamilton D Hansen O Higinbotham DW Holt RJ de Jager CW Jones MK Kaufman LJ Kinney ER Kramer K Lagamba L de Leo R Lerose J Lhuillier D Lindgren R Liyanage N McCormick K Meziani ZE Michaels R Moffit B Monaghan P Nanda S Paschke KD Perdrisat CF Punjabi V Qattan IA Ransome RD Reimer PE Reitz B Saha A Schulte EC Sheyor R Slifer K Solvignon P Sulkosky V 《Physical review letters》2007,98(18):182302
We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance. 相似文献
66.
A practical computational method is discussed for obtaining the rotational–vibrational molecular state densities of molecules with large amplitude torsional degrees of freedom (DoFs). This method goes beyond the traditional harmonic oscillator/rigid rotor or separable hindered rotor approximations in that it includes coupling between the torsion, the remaining vibrational modes, and the overall rotation. The method is based on the vibrationally adiabatic approximation whereby the torsional motion is assumed to be slow compared to the remaining vibrational DoFs although the nonseparability may be large. The torsional coordinate therefore parameterizes the rotational constants and the effective vibrational potential. A semiclassical method is then introduced to calculate the total state density in which the torsion is treated classically while the remaining coordinates are treated quantum mechanically. The method is also formulated for reactive problems in which the density of states is parameterized by a second large amplitude degree of freedom, the reaction coordinate. The performance of the method is assessed using the dissociation reaction of the hydrogen peroxide molecule and its isotopomers. It is found that the method performs well based on numerical tests. The torsional nonseparability is found to yield errors of factors of 2–3 in the statistical rate coefficient when compared with results of traditional separable models. 相似文献
67.
Boryl‐Functionalized σ‐Alkynyl and Vinylidene Rhodium Complexes: Synthesis and Electronic Properties 下载免费PDF全文
Prof. Dr. Holger Braunschweig Christopher K. L. Brown Dr. Rian D. Dewhurst Dr. J. Oscar C. Jimenez‐Halla Thomas Kramer Dr. Ivo Krummenacher Dr. Bernd Pfaffinger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(5):1427-1433
The synthesis, reactivity, and properties of boryl‐functionalized σ‐alkynyl and vinylidene rhodium complexes such as trans‐[RhCl(?C?CHBMes2)(PiPr3)2] and trans‐[Rh(C?CBMes2)(IMe)(PiPr3)2] are reported. An equilibrium was found to exist between rhodium vinylidene complexes and the corresponding hydrido σ‐alkynyl complexes in solution. The complex trans‐[Rh(C?CBMes2)(IMe)(PiPr3)2] (IMe=1,3‐dimethylimidazol‐2‐ylidene) was found to exhibit solvatochromism and can be quasireversibly oxidized and reduced electrochemically. Density functional calculations were performed to determine the reaction mechanism and to help rationalize the photophysical properties of trans‐[Rh(C?CBMes2)(IMe)(PiPr3)2]. 相似文献
68.
69.
The used liquid-phase epitaxy apparates are described and the experimental conditions of growth on GaP and Ga(AsP) onto GaAs-substrates are reported. The influence of growing conditions (temperature, cooling rate, composition of melt) on the quality of interface and on the inlusion of solvent are discussed. The consequence of varying degrees of substrat-misorientation on the surface morphology has been studied. 相似文献
70.
Following the initial synthesis of the fuchsones1I, (α, η -diphenyl-1,4-benzoquinone methides), numerous substituted members of this series have been described by workers interested in triphenylmethane dyes. The fuchsones have been synthesized by the sulfuric acid condensation of benzilic acid and appropriate phenol1, by dehydration of 4-hydroxytriphenylcarbinol2, by oxidation 4-hydroxytri-phenylmethane and by photochemically induced reactions benzophenones with 2,6-dialkylphenols4. 相似文献