SF_5CF_3与H反应机理的理论研究

Theoretical Study on the Reaction Mechanism of SF_5CF_3 with H

采用量子化学QCISD(T)/6-311++G(d,p)//B3LYP/6-311+G(d,p)方法研究了SF5CF3与H自由基的反应机理,对于反应势能面上的各驻点的几何构型进行了全参数优化,过渡态的真实性通过振动分析和内禀反应坐标(IRC)分析的结果得到了证实,共找到3条可能的反应通道.结果表明,SF5CF3+H→TS1→P1(CF3SF4(a)+HF)是最佳的反应通道.该反应通道需要克服的能垒高度为73.5 k J/mol,生成的产物CF3SF4(a)+HF的能量低于反应物SF5CF3+H的能量,属于放热反应,无论从热力学上还是从动力学上分析都是最有利的.

AQCISD （ T）/6-311＋＋G（ d, p）//B3LYP/6-311＋G（ d, p） method was employed to study the mechanism of the reaction of SF5 CF3 with H.Geometries of the stationary points were completely optimized.The transition stations were validated by the vibrational analysis and the internal reaction coordinate（IRC）calculations, which testified the authenticity of transition states. Three feasible reaction pathways have been studied.The results indicate that the pathway SF5CF3＋H→TS1→P1 （CF3SF4（a）＋HF） has the lowest activation energy of 73.5 kJ/mol.P1（CF3SF4（a）＋HF）which is the main product due to the largest energy of-217.4 kJ/mol.The pathway SF5 CF3＋H→TS1→P 1（ CF3 SF4（ a）＋HF） is the dominant channel of the title reaction from the reaction kinetics and thermodynamics.