Frömbgen Tom, Drysch Katrin, Tassaing Thierry, Buffeteau Thierry, Hollóczki Oldamur, Kirchner Barbara
Mulliken Center for Theoretical Chemistry, University of Bonn, Beringstraße 4, 53115, Bonn, Germany.
Institut des Sciences Moléculaires (ISM), UMR 5255, University of Bordeaux - CNRS - Bordeaux INP, Talence, 33400, France.
Angew Chem Int Ed Engl. 2025 Jul 7;64(28):e202502885. doi: 10.1002/anie.202502885. Epub 2025 May 30.
Here, we show that the four conformers of the regularly used ionic liquid anion bis(trifluoromethylsulfonyl)imide are true enantiomeric pairs by analyzing their calculated vibrational circular dichroism spectra. The significant modes involve those atoms of the anion that form specific hydrogen bond patterns with the chiral probe molecule propylene oxide. Adding this probe molecule to the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, the experimental and simulated spectra indicate intermolecular interaction between the chiral molecule and the liquid and thus the induction of chirality in the anion. This emergence of chirality in the ionic liquid takes place via the hydrogen bonding between the anion of the ionic liquid and the solute, which results in a redistribution of the symmetric occurrence of conformers to an asymmetric one. Altogether, this study reveals the mechanism of chiral induction from the propylene oxide molecule to the ionic liquid anion, while pointing out the importance of rational over a random choice of the ionic liquid building units.
在此,我们通过分析计算得到的振动圆二色光谱表明,常用离子液体阴离子双(三氟甲基磺酰)亚胺的四种构象体是真正的对映体对。重要的模式涉及阴离子中与手性探针分子环氧丙烷形成特定氢键模式的那些原子。将这种探针分子添加到离子液体1-乙基-3-甲基咪唑鎓双(三氟甲基磺酰)亚胺中,实验和模拟光谱表明手性分子与液体之间存在分子间相互作用,从而导致阴离子中手性的诱导。离子液体中这种手性的出现是通过离子液体阴离子与溶质之间的氢键作用发生的,这导致构象体对称出现向不对称出现的重新分布。总之,本研究揭示了从环氧丙烷分子到离子液体阴离子的手性诱导机制,同时指出了合理选择而非随机选择离子液体构建单元的重要性。