Höfft O, Bahr S, Himmerlich M, Krischok S, Schaefer J A, Kempter V
Institut für Physik und Physikalische Technologien, Technische Universität Clausthal, Leibnizstr. 4, D-38678 Clausthal-Zellerfeld, Germany.
Langmuir. 2006 Aug 15;22(17):7120-3. doi: 10.1021/la060943v.
The near-surface electronic structure of the room-temperature ionic liquid (RT-IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][Tf(2)N]) has been investigated with the combination of the electron spectroscopies metastable impact electron spectroscopy (MIES), ultraviolet photoelectron spectroscopy (UPS (HeI and HeII)), and monochromatized X-ray photoelectron spectroscopy (XPS). We find that the top of the valence band states originates from states of the cation (see also ref 1). The ultimately surface-sensitive technique MIES proves that the surface layer consists of both cations and anions. The temperature dependence of the spectra has been measured between about 160 and 610 K. Information on the glass transition and the possibility for low-temperature distillation of [EMIM][Tf(2)N] at reduced pressures is derived from the present results.
通过亚稳碰撞电子能谱（MIES）、紫外光电子能谱（UPS（HeI和HeII））以及单色化X射线光电子能谱（XPS）相结合的方法，对室温离子液体（RT-IL）1-乙基-3-甲基咪唑双（三氟甲基磺酰）亚胺（[EMIM][Tf₂N]）的近表面电子结构进行了研究。我们发现价带态的顶部源自阳离子的态（另见参考文献1）。极具表面敏感性的技术MIES证明表面层由阳离子和阴离子组成。在约160至610 K之间测量了光谱的温度依赖性。从目前的结果中得出了关于玻璃化转变以及[EMIM][Tf₂N]在减压下低温蒸馏可能性的信息。
