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在B3LYP/6-31G(d,p)水平上优化了Cl原子与CH3COCH2Cl反应的各驻点的几何构型,并在相同水平上通过频率计算和内禀反应坐标(IRC)分析对过渡态的结构和反应物、产物的连接性进行了验证。采用高精确模型G3MP2方法进行单点能计算,构建了反应的势能剖面。计算结果表明,标题反应有抽氢反应、加成-消除反应、取代反应3种反应机理6条反应通道。利用经典过渡态理论(TST)和正则变分过渡态理论(CVT)计算了各反应通道在200~2000 K温度范围内的速率常数,并用小区率隧道效应模型(SCT)对抽氢反应进行校正。计算结果显示,反应有一定的变分效应,计算的总反应速率常数与文献报道的实验值符合得较好,速率常数的三参数表达式为k=2.33×10-19T2.54exp(567.07/T)cm3·mol-1·s-1。
At each B3LYP / 6-31G (d, p) level, the geometry of each site of the reaction between Cl atoms and CH3COCH2Cl is optimized and the same state is solved by frequency calculation and intrinsic reaction coordinate (IRC) Structure and reactants, product connectivity was verified. The high energy model G3MP2 is used to calculate the single point energy, and the potential energy profile of the reaction is constructed. The calculation results show that there are six reaction channels in the title reaction including hydrogenation reaction, addition-elimination reaction and substitution reaction. The rate constants of each reaction channel in the temperature range from 200 K to 2000 K were calculated by classical transition state theory (TST) and regular variation transition state theory (CVT), and the hydrogen abstraction reaction was corrected by the cell-rate tunneling effect model (SCT) . The calculated results show that the reaction has a certain variational effect, and the calculated total reaction rate constant is in good agreement with the experimental values reported in the literature. The three-parameter expression of the rate constant is k = 2.33 × 10-19T2.54exp (567.07 / T ) cm3 · mol-1 · s-1.