F+CH_2CO的反应机理和动力学研究

Reaction Mechanism and Kinetics for the F+ CH_2CO Reaction

用 G3 (MP2 )方法对 F与 CH2 CO的反应进行研究 ,揭示了该反应的加成 -消除机理 .F原子首先与CH2 CO作用形成富能的中间体 CH2 FCO*,此加成反应为无势垒过程 .富能的 CH2 FCO*可进一步发生解离或异构化反应生成各种可能的产物 .其中 CO和 CH2 F可能为反应的主要产物 .根据从头算的结果 ,用RRKM-TST理论计算该反应的速率常数 .总包反应速率常数与温度存在弱的依赖关系 。

G3(MP2) theory is used to study the F+CH 2CO reaction. The calculations reveal a typical addition elimination mechanism for the title reaction. The reaction starts with F and (CH 2CO) reacting with each other to form the activated intermediate (CH 2FCO) *. This association reaction is found to be a barrierless process. CH 2FCO * can undergo further decomposition and isomerization reactions leading to various possible products. CO and CH 2F are found to be the dominant products. RRKM TST method is used to calculate the total and individual rate constants. The total rate constant shows a weak temperature dependence and a pressure independence.