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An ab initio molecular orbital calculation has been carried out for three different conformations of 1,3 propanediol, one of which permits intramolecular H-bond studied by ab initio quantum mechanical methods. The ΔE for H-bonding formation is compated to be 0.9 kcal/mole and the charge redistributions and molecular orbital energy changes are compared to those found in intermolecular H-bonds. 相似文献
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Laurens van Gelderen Gadi Rothenberg V. Roberto Calderone Karen Wilson N. Raveendran Shiju 《应用有机金属化学》2013,27(1):23-27
Copper immobilized on a functionalized silica support is a good catalyst for the homocoupling of terminal alkynes. The so‐called Glaser–Hay coupling reaction can be run in air with catalytic amounts of base. The copper catalyst is active for multiple substituted alkynes, in both polar and non‐polar solvents, with good to excellent yields (75–95%). Depending on the alkyne, full conversion can be achieved within 3–24 h. The catalyst was characterized by TGA, inductively coupled plasma and X‐ray photoelectron spectroscopy. Leaching tests confirm that the catalyst is and remains heterogeneous. Importantly, the overall reaction requires only alkyne and oxygen (in this case, air) as reagents, making this a clean catalytic oxidative coupling reaction. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Photoluminescence excitation spectroscopy and scanning-tunneling spectroscopy are used to study the electronic states in CdSe quantum rods that manifest a transition from a zero-dimensional to a one-dimensional quantum-confined structure. Both optical and tunneling spectra show that the level structure depends primarily on the diameter of the rod and not its length. With increasing diameter, the band gap and the excited state level spacings shift to the red. The level structure was assigned using a multiband effective-mass model, showing a similar dependence on rod dimensions. 相似文献
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Understanding solid/solid organic reactions 总被引:4,自引:0,他引:4
Rothenberg G Downie AP Raston CL Scott JL 《Journal of the American Chemical Society》2001,123(36):8701-8708
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