物理化学学报 >> 2008, Vol. 24 >> Issue (01): 8-12.doi: 10.3866/PKU.WHXB20080102

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烯烃分子在氢终止Si(100)-2×1表面的自由基链反应

延辉; 苑世领; 刘成卜   

  1. 山东大学理论化学研究所, 济南 250100
  • 收稿日期:2007-08-13 修回日期:2007-09-20 发布日期:2008-01-05
  • 通讯作者: 苑世领 E-mail:shilingyuan@sdu.edu.cn

Radical Chain Reaction of Alkene Molecule on H-terminated Si(100)-2×1 Surface

YAN Hui; YUAN Shi-Ling; LIU Cheng-Bu   

  1. Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
  • Received:2007-08-13 Revised:2007-09-20 Published:2008-01-05
  • Contact: YUAN Shi-Ling E-mail:shilingyuan@sdu.edu.cn

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摘要： 应用密度泛函理论(DFT)和从头计算分子动力学方法(ab initio MD)研究了不饱和烯烃在氢终止的Si(100)-2×1表面的自由基链反应. 计算表明, 自由基链反应中重要的一步是烷烃链自由基的氢抽提过程, 硅表面上邻近位置(the nearest neighbor, NN)的氢抽提比次邻近位置(the next-nearest neighbor, NNN)的氢抽提有一稍低的能垒. 从头算分子动力学显示, 过渡态的烷烃自由基与氢终止Si(100)-2×1表面上的氢原子能够很容易形成C—H键, 完成一个氢抽提过程, 同时在硅表面产生下一个孤电子, 继续引发链反应.

关键词: 从头算分子动力学, 氢终止, 自由基链反应, 氢抽提

Abstract: The density functional theory and ab initio molecular dynamic method were applied on the radical initiated chain reaction of unsaturated 1-alkene molecules on H-terminated Si(100)-2×1 surface. The results showed that the crucial step of the surface chain reaction, namely, the abstraction of a H atom from a nearby surface hydride unit, had a somewhat smaller activation energy from the nearest silicon site than that from the next nearest silicon site. Ab initio molecular dynamics showed that the H-abstraction on Si(100)-2×1 surface bound organic group with a carbon-centered radical was very easy to be obtained from the transition state, and a new silicon dangling bond was produced to lead to a surface chain reaction.

Key words: Ab initio molecular dynamic, H-terminated, Radical initiated chain reaction, H-abstraction