Yamada Toshiki, Mizuno Maya
Advanced ICT Research Institute, National Institute of Information and Communications Technology, 588-2 Iwaoka, Kobe 651-2492, Japan.
Radio Research Institute and Beyond 5G Research and Development Promotion Unit, National Institute of Information and Communications Technology, 4-2-1 Nukuikitamachi, Koganei, Tokyo 184-8795, Japan.
ACS Omega. 2022 Aug 22;7(34):29804-29812. doi: 10.1021/acsomega.2c02601. eCollection 2022 Aug 30.
We performed terahertz time-domain spectroscopy and infrared spectroscopy of imidazolium-based, pyridinium-based, and tetraalkylammonium-based tetrafluoroborate ionic liquids to study their characteristic intermolecular and intramolecular vibrational modes to clarify interactions between various cations and the tetrafluoroborate anion. It was found that the central frequency of the intermolecular vibrational band for these ionic liquids has a relatively high frequency, ranging from 90 to 100 cm. In the 900-1150 cm range, the intramolecular vibrational absorption band of the 3-fold degenerate mode of tetrafluoroborate anions in the ionic liquids was observed. Although the tetrafluoroborate anion is attributable to one of the weakly coordinated anions, the spectroscopic splitting behavior of the 3-fold degenerate mode differs depending on the cation species. It was revealed that the degenerate mode is very sensitive to local interactions between the tetrafluoroborate anion and each cation.
我们对咪唑基、吡啶基和四烷基铵基四氟硼酸盐离子液体进行了太赫兹时域光谱和红外光谱研究，以探究其特征性的分子间和分子内振动模式，从而阐明各种阳离子与四氟硼酸根阴离子之间的相互作用。结果发现，这些离子液体分子间振动带的中心频率相对较高，范围在90至100厘米。在900 - 1150厘米范围内，观察到离子液体中四氟硼酸根阴离子的三重简并模式的分子内振动吸收带。尽管四氟硼酸根阴离子属于弱配位阴离子之一，但三重简并模式的光谱分裂行为因阳离子种类而异。结果表明，简并模式对四氟硼酸根阴离子与每个阳离子之间的局部相互作用非常敏感。
