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31.
B. Wyncke F. Bréhat H. Kharroubi 《International Journal of Infrared and Millimeter Waves》1997,18(2):475-489
Spectroscopic studies using far infrared reflectivity and transmissivity measurements between 10 and 600 cm−1, were performed on plane parallel quartz crystal plates, in the temperature range 10–300 K. The temperature dependence of
the optical mode parameters is reporeted for both polarizations parallel and perpendicular to the c-axis. The extraordinary
optical constants of quartz are determined at 10 and 300 K, from the A2 transmissivity channeled spectrum, between 10 and 300 cm−1. 相似文献
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Bruneau C 《Angewandte Chemie (International ed. in English)》2005,44(16):2328-2334
Transformations of enynes in the presence of transition-metal catalysts have played an important role in the preparation of a variety of cyclic compounds. Recent developments in the activation of triple carbon-carbon bonds by electrophilic metal centers have provided a new entry to the selective synthesis of cyclopropane derivatives from enynes. The mechanisms of these reactions involve catalytic species with both ionic and cyclopropylcarbenoid character. This type of activation will undoubtedly be further developed for application to other unsaturated hydrocarbons and inspire new catalytic cascade reaction sequences. This Minireview discusses the recent developments in electrophilic activation of enynes and shows that simple catalysts such as [Ru(3)(CO)(12)], PtCl(2), and cationic gold complexes are efficient precursors to promote the formation of functional polyclic compounds. 相似文献
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Bayesian Regularized Neural Networks (BRNNs) employing Automatic Relevance Determination (ARD) are used to construct a predictive model for the distribution coefficient logD7.4 from an in-house data set of 5000 compounds with experimental endpoints. A method for assessing the accuracy of prediction is established based upon a query compound's distance to the training set. logD7.4 predictions are also dynamically corrected with an associated library of compounds of continuously updated, experimentally measured logD7.4 values. A comparison of local models and associated libraries comprising separate ionization class subsets of compounds to compounds of a homogeneous ionization class reveals in this case that local models and libraries have no advantage over global models and libraries. 相似文献
37.
Hania Hebbache Thomas Jerphagnon Christian Bruneau Jean-Luc Renaud 《Journal of organometallic chemistry》2010,695(6):870-874
β-Aminoesters were prepared in two simple steps from β-ketoesters derivatives and primary amines under mild conditions. Their hydrogenation was performed at 50 °C in the presence of several organometallic catalysts under acidic conditions. The new β-N-substituted aminoesters were isolated in moderate to good yields. 相似文献
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The development in Paper I is extended to multifunctional condensations where the functional groups exhibit unequal reactivities induced by substitution effects in the course of the polymerization. A system R(A)2/R′(B)3 is examined to determine how the gel point varies with the strength and positive or negative sense of the substitution effect. As in Paper I, intramolecular interactions are not considered. 相似文献