The Assembly and Spectroscopic Interrogation of Hydrogen Clusters in Helium Droplets

在这个由化学部实验物理化学计划资助的项目中，Vilesov将研究捕获在超冷氦液滴中的氢分子和团簇的基本性质。这项工作由两部分组成。在第一种中，焦点集中在聚集成不同性质的生色团的H2、D2和HD分子上。第二部分将致力于研究整齐的氢团簇，特别关注那些大小在30分子以下的氢团簇。红外和CARS光谱将用于这些研究。对捕获在超冷液氦液滴中的分子和团簇的研究提供了传统技术无法获得的关于它们行为的新信息。被捕获的物种不仅在液滴中振动，而且还在液滴中旋转，这表明被捕获的物种与包埋浴之间的相互作用很小。相对于与气体分子有关的转动能，转动能的微小变化允许对将分子结合到液滴中的力进行定量评估。

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Vilesov will investigate fundamental properties of hydrogen molecules and clusters trapped in ultracold helium droplets. The work consists of two parts. In the first, the focus is on H2, D2, and HD molecules clustered to chromophores with different properties. The second part will be devoted to the study of neat hydrogen clusters, special attention being given to those in the size range below 30 molecules. Infrared and CARS spectroscopy will be employed in these investigations.Research on molecules and clusters entrapped in ultracold droplets of liquid helium provides new information on their behavior not available with conventional techniques. Not only do the trapped species vibrate, but they also rotate in the droplets, which indicates that the interaction between the trapped species and the embedding bath is minimal. The slight changes in the rotational energies relative of those that pertain to gaseous molecules allow a quantitative assessment of the forces that bind the molecules into the droplets.