Gas–solid reactions of single crystals: A study of reactions of NH3 and NO2 with single crystalline organic substrates by infrared microspectroscopy
- 作者：Samantha L. Jenkins ; Matthew J. Almond ; Samantha D.M. Atkinson ; Peter Hollins and John P. Knowles
- 关键词：Gas– ; solid reactions ; Carboxylic acid ; Hydantoin ; Solvent-free nitration ; Infrared microspectroscopy ; Raman microspectroscopy
- 刊名：Spectrochimica Acta Part A ; Molecular and Biomolecular Spectroscopy
- 出版年：2005
- 期刊代码：99_13861425
- 类别：ch
- 出版时间：December 2005
- 卷：62
- 期：4-5
- 页码：1131-1139
- 文件大小：193 K
摘要
Reaction of single crystals of benzoic and trans-cinnamic acids with 200 Torr pressure of ammonia gas in a sealed glass bulb at 20 °C generates the corresponding ammonium salts; there is no sign of any 1:2 adduct as has been reported previously for related systems. Isotopic substitution using ND3 has been used to aid identification of the products. Adipic acid likewise reacts with NH3 gas to form a product in which ammonium salts are formed at both carboxylic acid groups. Reaction of 0.5 Torr pressure of NO2 gas with single crystals of 9-methylanthracene and 9-anthracenemethanol in a flow system generates nitrated products where the nitro group appears to be attached at the 10-position, i.e. the position trans to the methyl or methoxy substituent on the central ring. Isotopic substitution using 15NO2 has been used to confirm the identity of the bands arising from the coordinated NO2 group. The products formed when single crystals of hydantoin are reacted with NO2 gas under similar conditions depend on the temperature of the reaction. At 20 °C, a nitrated product is formed, but at 65 °C this gives way to a product containing no nitro groups. The findings show the general applicability of infrared microspectroscopy to a study of gas–solid reactions of organic single crystals.