排序方式: 共有23条查询结果,搜索用时 15 毫秒
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John G. D'Angelo Jeremy A. Cody Christian Larrabee Danica J. Ostrander Kyle W. Rugg Donna Mamangun 《合成通讯》2013,43(23):3224-3232
Herein, we report new reactivity of the conducting polymer, poly-(3,4-ethylenedioxy thiophene) (PEDOT), where PEDOT mediates a Ritter reaction between alcohols and acetonitrile. The yields were variable and in most cases competitive with results obtained using sulfuric acid. Attempts at a stoichiometric reaction between benzonitrile and diphenylmethanol are also reported herein. Finally, described here are preliminary mechanistic studies that suggest PEDOT is behaving as an alcohol-selective or specific Lewis acid. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for full experimental and spectral details. 相似文献
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An impulse approximation calculation is made on the reaction 51V(γ, π+)51Ti from the region just above photopion threshold to the tail of the (3, 3) resonance. Pion final state distortions are taken into account through realistic optical potentials. Results are compared to those for plane-wave and surface-produced pions and to recent experiment. Comparison is made between surface-produced pions and pions distorted by the s-wave component of the optical potential. 相似文献
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Molar extinction coefficients of some carbohydrates viz. l-arabinose (C5H10O5), d-glucose (C6H12O6), d-mannose (C6H12O6), d-galactose (C6H12O6), d(-) fructose (C6H12O6) and maltose (C12H24O12) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by gamma ray transmission method in a
narrow beam good geometry set-up. These coefficients have been found to depend upon the photon energy following a 4-parameter
polynomial. These extinction coefficients for different sugars having the same molecular formula have same values varying
within experimental uncertainty. Within concentration ranges studied, Beer-Lambert law is obeyed very well. 相似文献
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Deguchi K Ishikawa M Yokokura T Ogata I Ito S Mimura T Ostrander C 《Rapid communications in mass spectrometry : RCM》2002,16(22):2133-2141
A new method providing enhanced sensitivity for the analysis of oligonucleotides using an on-line coupled system of reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization ion-trap mass spectrometry (ESI-MS) has been developed. The presented method allows the use of the standard gradient elution of 0.1 M triethylammonium acetate (TEAA) buffer (adjusted to pH 7.0 with acetic acid) and acetonitrile that is typically used for the separation of oligonucleotides in RP-HPLC. An added feature of this method is the ability to combine and mix additional 0.1 M imidazole in acetonitrile after the separation column for improved ESI-MS performance. This is similar to the post-column reaction method in liquid chromatography (LC) and the liquid sheath flow method in LC/ESI-MS, both of which offer the advantage of not compromising the chromatographic separation conditions. The application of this new method is demonstrated to afford improved sensitivity for the analysis of oligonucleotides (20-50 mer) via on-line coupled HPLC/ESI-MS analysis and purification systems. 相似文献
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离子液体作为溶剂/催化剂用于卤代烃对胺的选择性烷基化反应 总被引:1,自引:0,他引:1
在三乙胺存在下,在离子液体([bmim]I和[bmim]PF6)中进行了各种卤代烃对胺类化合物中氨基的选择性烷基化反应.反应在相对温和的条件下进行,转化率和选择性优异.离子液体可以回收并重复使用. 相似文献
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The structure of 1,3-dehydro-5-adamantyl cation and its isoelectronic boron analogue 1,3-dehydro-5-boraadamantane as well as some related adamantane systems, hitherto unknown as persistent long-lived species, were investigated by using the density functional theory (DFT) method. (13)C and (11)B NMR chemical shifts of the compounds were also calculated using the IGLO method. Stabilization of the systems due to homoconjugation is discussed. 相似文献
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