Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
J Chem Phys. 2012 Jan 28;136(4):044305. doi: 10.1063/1.3678011.
High resolution IR spectra of aniline, styrene, and 1,1-diphenylethylene cations embedded in superfluid helium nanodroplets have been recorded in the 300-1700 cm(-1) range using a free-electron laser as radiation source. Comparison of the spectra with available gas phase data reveals that the helium environment induces no significant matrix shift nor leads to an observable line broadening of the resonances. In addition, the IR spectra have provided new and improved vibrational transition frequencies for the cations investigated, as well as for neutral aniline and styrene. Indications have been found that the ions desolvate from the droplets after excitation by a non-evaporative process in which they are ejected from the helium droplets. The kinetic energy of the ejected ions is found to be ion specific and to depend only weakly on the excitation energy.
采用自由电子激光作为辐射源，在 300-1700cm(-1) 范围内记录了嵌入在超流氦纳米液滴中的苯胺、苯乙烯和 1,1-二苯乙烯阳离子的高分辨率红外光谱。将光谱与可用的气相数据进行比较表明，氦环境不会引起明显的基质位移，也不会导致共振的可观测线宽增加。此外，红外光谱还为所研究的阳离子以及中性苯胺和苯乙烯提供了新的和改进的振动跃迁频率。有迹象表明，离子在非蒸发过程中从液滴中解吸出来，在这个过程中，它们从氦液滴中被喷射出来。发现喷射出的离子的动能具有离子特异性，并且仅微弱地依赖于激发能。
