物理化学学报 >> 2012, Vol. 28 >> Issue (08): 18491849-1853..doi: 10.3866/PKU.WHXB201206081

理论与计算化学 上一篇    下一篇

羰基化合物在Si(100)表面[2+2]环加成和α-H裂解反应的选择性

张继超1, 程学礼2, 程玉桥1, 孟祥华1, 刘永军2, 刘成卜2   

  1. 1. 中国石化胜利油田分公司, 地质科学研究院, 山东 东营 257015;
    2. 山东大学化学与化工学院, 济南 250100
  • 收稿日期:2012-04-01 修回日期:2012-06-08 发布日期:2012-07-10
  • 通讯作者: 刘永军 E-mail:yongjunliu_1@sdu.edu.cn
  • 基金资助:

    国家自然科学基金(21173129)资助项目

Selectivity of [2+2] C=O Cycloaddition and α-H Cleavage of Carbonyl Compounds on Si(100) Surface

ZHANG Ji-Chao1, CHENG Xue-Li2, CHENG Yu-Qiao1, MENG Xiang-Hua1, LIU Yong-Jun2, LIU Cheng-Bu2   

  1. 1. Geological Scientific Research Institute, Shengli Oilfield Company of SINOPEC, Dongying 257015, Shandong Province, P. R. China;
    2. School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, P. R. China
  • Received:2012-04-01 Revised:2012-06-08 Published:2012-07-10
  • Contact: LIU Yong-Jun E-mail:yongjunliu_1@sdu.edu.cn
  • Supported by:

    The project was supported by the Natural Science Foundation of China (21173129).

摘要:

最近研究表明: 丙酮能与半导体Si(100)表面发生[2+2]环加成和α-H 裂解反应形成相应的Si―C键或Si―O键, 在半导体材料的合成方面具有重要意义. 为进一步弄清不同羰基化合物在Si(100)表面的反应机理,本文应用密度泛函理论方法在B3LYP/6-311++G(d,p)//6-31G(d)水平上较为系统地研究了一系列羰基化合物CH3COR (R=CH3, H, C2H5, C6H5)与Si(100)表面的反应. 研究结果表明: 不论是[2+2]环加成反应还是α-H 裂解反应都对应较低的反应势垒(小于25 kJ·mol-1); 环加成反应的势垒比α-H 裂解反应的势垒略高; 羰基上的取代基对反应势垒的影响较少; α-H裂解反应产物为动力学和热力学控制产物; 对丁酮来说, 1-位和3-位H原子的裂解反应都比较容易, 势垒相差很小. 这些结果表明羰基化合物与Si(100)表面的反应将得到多种产物.

关键词: 密度泛函理论, 环加成反应, α-H裂解反应, 羰基化合物

Abstract:

Recent studies have demonstrated that a simple ketone [acetone, (CH3)2C=O)] reacts with the Si(100) surface in a [2+2] C=O cycloaddition or by α-H cleavage to form Si―C and/or Si―O σ-bonds. To understand the reactivity of carbonyl compounds bearing different substitutes, the [2 + 2] C=O cycloaddition and α-H cleavage of carbonyl compounds CH3COR (R=CH3, H, C2H5, C6H5) on Si(100) surface have been investigated using density functional theory at the B3LYP/6-311 ++ G(d,p)//6-31G(d) level. Our calculation results reveal that: (1) both cycloaddition and α-H cleavage corresponds to very low energy barriers (lower than 25 kJ·mol-1), and the energy barrier for cycloaddition is slightly higher than α-H cleavage; (2) the substituents on the carbonyl compound [CH3COR] has only a minor influence on the energy barrier; (3) the α-H cleavage reactions are thermodynamically and kinetically more favorable than cycloadditions; (4) for the α-H cleavage of butanone, reactions at C1 and C3 positions are competitive. These findings suggest that the reactions of ketone derivatives with Si(100) surface will generate multiple products.

Key words: Clycloaddition, α-H cleavage, Carbonyl compound, Density functional theory

MSC2000: 

  • O641