Photoionization and Photofragmentation of SF6 in Helium Nanodroplets

详细信息    查看全文

• 作者：Darcy S. Peterka ; Jeong Hyun Kim ; Chia C. Wang ; Daniel M. Neumark
• 刊名：Journal of Physical Chemistry B
• 出版年：2006
• 出版时间：October 12, 2006
• 年：2006
• 卷：110
• 期：40
• 页码：19945 - 19955
• 全文大小：357K
• 年卷期：v.110,no.40(October 12, 2006)
• ISSN：1520-5207

文摘

The photoionization of He droplets doped with SF₆ was investigated using tunable vacuum ultraviolet (VUV)synchrotron radiation from the Advanced Light Source (ALS). The resulting ionization and photofragmentationdynamics were characterized using time-of-flight mass spectrometry combined with photofragment andphotoelectron imaging. Results are compared to those of gas-phase SF₆ molecules. We find dissociativephotoionization to SF₅⁺ to be the dominant channel, in agreement with previous results. Key new findingsare that (a) the photoelectron spectrum of the SF₆ in the droplet is similar but not identical to that of thegas-phase species, (b) the SF₅⁺ photofragment velocity distribution is considerably slower upon dropletphotoionization, and (c) fragmentation to SF₄⁺ and SF₃⁺ is much less than in the photoionization of bare SF₆.From these measurements we obtain new insights into the mechanism of SF₆ photoionization within thedroplet and the cooling of the hot photofragment ions produced by dissociative photoionization.