An in situ high pressure FTIR study on molecular interactions of ketones, esters, and amides with dense phase carbon dioxide
An in situ high pressure FTIR study on molecular interactions of ketones, esters, and amides with dense phase carbon dioxide
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DOI：
10.1016/j.supflu.2008.03.009
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发表时间：
2008-09-01
影响因子：
3.9
通讯作者：
Arai, M.
中科院分区：
文献类型：
--
作者：
Akiyama, Y.;Fujita, S.;Arai, M.
通过原位高压FTIR测量研究了各种羰基化合物（酮、酯和酰胺）与密相CO2之间的相互作用。这些化合物的气相和液相光谱也被测量，以提供准确的参考数据，这些已被比较与那些在正己烷和密相CO2在各种压力下获得。羰基IR吸收的频率是羰基键强度的量度，并且在稠密CO2介质中，在气相和液相中观察到的频率之间。取代基对v（C=O）吸收带的影响是相同的气体，液体和致密的CO2光谱，它是有关的电子给取代基的性质。当羰基化合物的正己烷溶液被稀释时，v（C=O）吸收带发生蓝移。相比之下，这些带在稠密的CO2是红移与增加压力（稀释CO2）。随着CO2压力的增加，酰胺>酯>酮的红移较大。(c)2008 Elsevier B.V.保留所有权利。
The interactions between a variety of carbonyl compounds (ketones, esters, and amides) and dense phase CO2 have been investigated by in situ high pressure FTIR measurements. The gas and liquid phase spectra of these compounds have also been measured to provide accurate reference data, and these have been compared with those obtained in n-hexane and dense phase CO2 at a variety of pressures. The frequency of the carbonyl IR absorption is a measure of the strength of the carbonyl bond, and in the dense CO2 medium, is in between that observed in the gaseous and liquid phases. The substituent effect on the v(C=O) absorption bands is the same for the gas, liquid, and dense CO2 spectra and it is related to the electron donating nature of the substituents. When solutions of carbonyl compounds in n-hexane are diluted, the v(C=O) absorption bands are blue-shifted. In contrast, these bands in dense CO2 are red-shifted with increasing pressure (dilution by CO2). The red shift with increasing CO2 pressure is larger in amides > esters > ketones. (c) 2008 Elsevier B.V. All rights reserved.