Institut des Sciences Moléculaires, UMR 5255, CNRS, Université Bordeaux I, 351 Cours de la Libération, 33405 Talence Cedex, France.
Appl Spectrosc. 2010 Jan;64(1):112-9. doi: 10.1366/000370210790572089.
The infrared (IR) spectra of ionic liquids involving 1-butyl-3-methylimidazolium (BMI) and the (CF(3)SO(2))(2)N(-), BF(4)(-), or PF(6)(-) anions, recorded in the transmission and attenuated total reflection (ATR) modes, exhibit strong differences in the most intense anion absorption profiles. These distortions come from optical effects and make difficult any quantitative analysis of, for example, the antisymmetric stretching vibrations of the BF(4)(-) and PF(6)(-) anions. A method is proposed to determine the optical constants, from which any type of experimental spectrum can be simulated. It is then possible to use the anion vibrational bands as spectroscopic probes of the local interactions occurring in the neat ionic liquids and in solutions. This is illustrated by a direct identification of ion pairs and separated ions in the IR spectra of BMI-PF(6) solutions.
涉及 1-丁基-3-甲基咪唑鎓（BMI）和（CF3SO2）2N-、BF4-或 PF6-阴离子的离子液体的红外（IR）光谱，以透射和衰减全反射（ATR）模式记录，在最强的阴离子吸收轮廓中表现出强烈的差异。这些扭曲来自光学效应，使得例如 BF4-和 PF6-阴离子的反对称伸缩振动的任何定量分析变得困难。提出了一种确定光学常数的方法，从中可以模拟任何类型的实验光谱。然后可以将阴离子振动带用作在纯离子液体和溶液中发生的局部相互作用的光谱探针。这通过 BMI-PF6溶液的 IR 光谱中离子对和分离离子的直接识别得到说明。
