Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom.
J Chem Phys. 2012 May 14;136(18):184301. doi: 10.1063/1.4706604.
Low-energy dissociative electron attachment (DEA) to the CF(2)Cl(2) and CF(3)Cl molecules in a water cluster environment is investigated theoretically. Calculations are performed for the water trimer and water hexamer. It is shown that the DEA cross section is strongly enhanced when the attaching molecule is embedded in a water cluster, and that this cross section grows as the number of water molecules in the cluster increases. This growth is explained by a trapping effect that is due to multiple scattering by water molecules while the electron is trapped in the cluster environment. The trapping increases the resonance lifetime and the negative ion survival probability. This confirms qualitatively existing experiments on electron attachment to the CF(2)Cl(2) molecule placed on the surface of H(2)O ice. The DEA cross sections are shown to be very sensitive to the position of the attaching molecule within the cluster and the orientation of the electron beam relative to the cluster.
在水环境中，对 CF(2)Cl(2) 和 CF(3)Cl 分子的低能离解电子俘获（DEA）进行了理论研究。计算了三聚水和六聚水的情况。结果表明，当附着分子嵌入水分子簇中时，DE A 截面会大大增强，并且随着簇中水分子数量的增加，该截面会增加。这种增长是由电子在簇环境中被捕获时通过水分子的多次散射引起的捕获效应引起的。捕获增加了共振寿命和负离子的存活率。这定性地证实了现有的关于 CF(2)Cl(2) 分子在 H(2)O 冰表面上的电子俘获实验。结果表明，DE A 截面对附着分子在簇内的位置以及电子束相对于簇的方向非常敏感。
