高等学校化学学报

高等学校化学学报 ›› 2001, Vol. 22 ›› Issue (2): 265.

• 研究论文 • 上一篇    下一篇

C60与硅烯环加成反应机理的理论研究

夏树伟1,2, 尚贞锋1, 陈兰1, 潘荫明1, 赵学庄1, 唐敖庆1,3   

  1. 1. 南开大学化学系, 天津 300071;
    2. 青岛海洋大学化学化工学院, 青岛 266003;
    3. 吉林大学理论化学研究所, 长春 130023
  • 收稿日期:1999-12-03 出版日期:2001-02-24 发布日期:2001-02-24
  • 通讯作者: 赵学庄(1933年出生),男,教授,博士生导师,从事化学动力学与理论化学研究.E-mail:zhaoxzh@nankai.edu.cn E-mail:zhaoxzh@nankai.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:20073022)资助

Theoretical Studies on the Mechanism Cycloaddition Reaction of Silylene with C60

XIA Shu-Wei1,2, SHANG Zhen-Feng1, CHEN Lan1, PAN Yin-Ming1, ZHAO Xue-Zhuang1, TANG Au-Chin1,3   

  1. 1. Department of Chemistry, Nankai University, Tianjin 300071, China;
    2. College of Chemistry and Chemical -Engineering, Ocean-University of Qingdao, Qingdao 266003, China;
    3. Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
  • Received:1999-12-03 Online:2001-02-24 Published:2001-02-24

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摘要： 用半经验AM1法研究了C60与单态硅烯环加成反应机理.经Berny梯度法优化得到反应的过渡态,并进行了振动分析确认.计算结果表明:硅烯在C60的66键上的加成反应分两步,第一步反应物生成中间配合物,无势垒;第二步由中间配合物经过渡态变为产物.65键上的加成反应分三步,第一步由反应物生成中间配合物,第二步由中间配合物经过渡态I得到闭环结构的中间体,第三步由中间体经过渡态Ⅱ形成产物.66键加成反应的活化势垒较低,从反应机理和动力学角度解释了66键加成优于65键加成的原因.

关键词: C60, 硅烯, 环加成反应, 过渡态, AM1

Abstract: The cycloaddition reaction of silylene(SiH2) and C60 have been studied by using the semi-empiri- cal method AM1, a reasonable mechanism of the reaction has been suggested. All the geometry of the sta- tionary points on the reaction path have been optimized by energy gradient technique and the transition states were characterized by vibration frequency analysis. The calculation results show that the reaction mechanism is different between 6-6 and 6-5 bond addition. The 6-6 bond cycloaddition reaction proceedvia two steps: (1) Silylene and C60 form an intermediate complex; (2) The closed isomer of C60SiH2 is formedvia TSfrom intermediate complex. After being corrected by zero-point energies the barriers is 0.45 kJ·mol-1. While the 6-5 cycloaddition reaction is of three steps: (1) An intermediate complex is formed from the reactants C60 and SiH2 with no barrier. (2) The closed intermediate is formedvia TS(Ⅰ). After being corrected by zero-point energies the barriers is 9.19 kJ·mol-1. (3) The opened isomer of C60SiH2 is producedvia TS(Ⅱ) with the barrier of 4.33 kJ·mol-1. The reasons that silylene cycloaddition should take place across 6-6 bond rather than 6-5 bond of C60 are explained from the reaction mechanism and kinetic factors.

Key words: C60, Silylene, Cycloaddition, TS, AM1

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