Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences , Flemingovo nam. 2 , 16610 Prague 6 , Czech Republic.
Department of Chemistry , University of Southern California , Los Angeles , California 90089-0482 , United States.
J Am Chem Soc. 2019 Feb 6;141(5):1838-1841. doi: 10.1021/jacs.8b10942. Epub 2019 Jan 25.
Photoelectron spectroscopy of microjets expanded into vacuum allows access to orbital energies for solute or solvent molecules in the liquid phase. Microjets of water, acetonitrile and alcohols have previously been studied; however, it has been unclear whether jets of low temperature molecular solvents could be realized. Here we demonstrate a stable 20 μm jet of liquid ammonia (-60 °C) in a vacuum, which we use to record both valence and core-level band photoelectron spectra using soft X-ray synchrotron radiation. Significant shifts from isolated ammonia in the gas-phase are observed, as is the liquid-phase photoelectron angular anisotropy. Comparisons with spectra of ammonia in clusters and the solid phase, as well as spectra for water in various phases potentially reveal how hydrogen bonding is reflected in the condensed phase electronic structure.
光电电子能谱学的微喷射扩展到真空中，允许进入液相中溶质或溶剂分子的轨道能量。以前已经研究了水、乙腈和醇的微喷射；然而，低温分子溶剂的喷射是否能够实现还不清楚。在这里，我们展示了一种稳定的 20μm 低温氨（-60°C）微喷射在真空中，我们使用它来记录软 X 射线同步辐射的价和芯级能带光电电子能谱。与气相中孤立氨相比，观察到明显的位移，以及液相光电电子角各向异性。与氨在团簇和固态中的光谱以及各种相态下的水的光谱的比较，可能揭示了氢键如何反映在凝聚相电子结构中。
