1-丁基-3-甲基咪唑四氟硼酸盐离子液体上饱和蒸汽的组成：汽化过程的多技术研究

The Composition of Saturated Vapor over 1-Butyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid: A Multi-Technique Study of the Vaporization Process.

作者信息

Dunaev Anatoliy M, Motalov Vladimir B, Kudin Lev S

机构信息

Research Institute of Thermodynamics and Kinetics, Ivanovo State University of Chemistry and Technology, 153000 Ivanovo, Russia.

出版信息

Entropy (Basel). 2021 Nov 8;23(11):1478. doi: 10.3390/e23111478.

DOI:10.3390/e23111478

PMID:34828176

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8625100/

Abstract

A multi-technique approach based on Knudsen effusion mass spectrometry, gas phase chromatography, mass spectrometry, NMR and IR spectroscopy, thermal analysis, and quantum-chemical calculations was used to study the evaporation of 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF). The saturated vapor over BMImBF was shown to have a complex composition which consisted of the neutral ion pairs (NIPs) [BMIm][BF], imidazole-2-ylidene CNHBF, 1-methylimidazole CNH, 1-butene CH, hydrogen fluoride HF, and boron trifluoride BF. The vapor composition strongly depends on the evaporation conditions, shifting from congruent evaporation in the form of NIP under Langmuir conditions (open surface) to primary evaporation in the form of decomposition products under equilibrium conditions (Knudsen cell). Decomposition into imidazole-2-ylidene and HF is preferred. The vapor composition of BMImBF is temperature-depended as well: the fraction ratio of [BMIm][BF] NIPs to decomposition products decreased by about a factor of three in the temperature range from 450 K to 510 K.

摘要

采用基于克努森 effusion 质谱、气相色谱、质谱、核磁共振和红外光谱、热分析以及量子化学计算的多技术方法，研究了 1-丁基-3-甲基咪唑四氟硼酸盐（BMImBF）的蒸发情况。结果表明，BMImBF 上方的饱和蒸汽具有复杂的组成，其中包括中性离子对（NIPs）[BMIm][BF]、咪唑-2-亚基 CNHBF、1-甲基咪唑 CNH、1-丁烯 CH、氟化氢 HF 和三氟化硼 BF。蒸汽组成强烈依赖于蒸发条件，从朗缪尔条件（开放表面）下以 NIP 形式的一致蒸发，转变为平衡条件（克努森池）下以分解产物形式的初次蒸发。分解为咪唑-2-亚基和 HF 是优先发生的。BMImBF 的蒸汽组成也取决于温度：在 450 K 至 510 K 的温度范围内，[BMIm][BF] NIPs 与分解产物的分数比降低了约三倍。