Smyth M, Kohanoff J, Fabrikant I I
Atomistic Simulation Centre, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland.
Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA and Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom.
J Chem Phys. 2014 May 14;140(18):184313. doi: 10.1063/1.4874841.
Low-energy electron-impact hydrogen loss due to dissociative electron attachment (DEA) to the uracil and thymine molecules in a water cluster environment is investigated theoretically. Only the A(')-resonance contribution, describing the near-threshold behavior of DEA, is incorporated. Calculations are based on the nonlocal complex potential theory and the multiple scattering theory, and are performed for a model target with basic properties of uracil and thymine, surrounded by five water molecules. The DEA cross section is strongly enhanced when the attaching molecule is embedded in a water cluster. This growth is due to two effects: the increase of the resonance lifetime and the negative shift in the resonance position due to interaction of the intermediate negative ion with the surrounding water molecules. A similar effect was earlier found in DEA to chlorofluorocarbons.
从理论上研究了在水团簇环境中，通过解离电子附着（DEA）到尿嘧啶和胸腺嘧啶分子上导致的低能电子碰撞氢损失。仅纳入了描述DEA近阈值行为的A(')-共振贡献。计算基于非局部复势理论和多重散射理论，针对具有尿嘧啶和胸腺嘧啶基本性质、被五个水分子包围的模型靶进行。当附着分子嵌入水团簇中时，DEA截面会显著增强。这种增长归因于两种效应：共振寿命的增加以及中间负离子与周围水分子相互作用导致的共振位置负移。类似的效应早前在DEA与氯氟烃的反应中也有发现。
