Cai Chen-Bo, Han Qing-Juan, Tang Li-Juan, Xu Lu, Wu Hai-Long, Jiang Jian-Hui, Yu Ru-Qin
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Talanta. 2009 Apr 30;78(2):337-41. doi: 10.1016/j.talanta.2008.11.022. Epub 2008 Nov 25.
An unlooked-for experimental observation that in near-infrared spectroscopy (NIR) the absorption peak of the second overtone of aniline adsorbed by 13X molecular sieve nearly disappeared led us investigate a fundamental question: the behavior of NIR when the outside space surrounding a molecule is too small to allow the molecule to vibrate freely. Through NIR of various organic compounds adsorbed by different porous inorganic materials like 13X molecular sieve, silica gel and active aluminium oxide, and NIR of supramolecular cyanuric acid-melamine, we can reasonably confirm a theoretical inference that in the micro-environment above, all intensities of NIR absorbance decrease, and the second overtone decreases more than the first overtone does. Furthermore, one distinct feature of NIR, higher sensitivity to the size of micro-environmental space as compared with mid-infrared (MIR), and its potential application to the study of supramolecular structure are outlined by our experiments.
一项意外的实验观察结果，即在近红外光谱（NIR）中，被13X分子筛吸附的苯胺的二次泛频吸收峰几乎消失，促使我们去研究一个基本问题：当分子周围的外部空间太小而无法让分子自由振动时近红外光谱的表现。通过对被不同多孔无机材料（如13X分子筛、硅胶和活性氧化铝）吸附的各种有机化合物进行近红外光谱分析，以及对超分子氰尿酸-三聚氰胺进行近红外光谱分析，我们可以合理地证实一个理论推断，即在上述微环境中，近红外吸收的所有强度都会降低，并且二次泛频比一次泛频降低得更多。此外，我们的实验还概述了近红外光谱的一个显著特征，即与中红外（MIR）相比，对微环境空间大小的敏感性更高，以及其在超分子结构研究中的潜在应用。
