扶手椅型(5,5)单壁硼氮纳米管与臭氧环加成反应机理的理论研究

用半经验AM1方法和密度泛函B3LYP方法研究了扶手椅型(5，5)单壁硼氮纳米管和臭氧的1，3-偶板环加成反应，采用Bemy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，O3在SWBNNT(5，5)的1，2和1，3键上的加成反应为一步反应，1，2加成反应的活化势垒较1，3加成反应的低11．02kJ／mol，从动力学角度解释了1，2加成优于1，3加成的原因，还讨论了产物的能带结构和导电性变化。

THEORETICAL STUDIES ON THE MECHANISM OF CYCLOADDITION REACTION OF OZONE WITH SWBNNT (5,5)

dipolar cycloaddition reaction of ozone to SWBNNT(5,5) has been studied by using the methods of semi-empirical AM1 and the DFT/B3LYP calculations. A reasonable mechanism of the reaction has been suggested. All the geometries of the stationary points on the reaction path were optimized by energy gradient technique and the transition states were characterized by vibration frequency analysis. The calculation results show that the cycloaddition of ozone on 1,2 bond and 1,3 bond of SWBNNT(5,5) are both one-step reactions. The barriers are 42.23 kJ/mol of 1,2 bond and 53.25 kJ/mol of 1,3 bond cycloaddition reactions respectively. The reasons that cycloaddition reaction should take place at 1,2 bond rather than 1,3 bond of SWBNNT(5,5) were explained by the kinetic factors. The changes in energy band structure and conductivity of these cycloadditional products were also discussed from the calculated results.