Ganzález-Lafont Angels, Moreno Miquel, Lluch José M
Contribution from the Departament de Química, Universitat Autonoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
J Am Chem Soc. 2004 Oct 13;126(40):13089-94. doi: 10.1021/ja039561r.
Variational transition state theory has been used to calculate the kinetic isotope effects affecting product ratios in the reaction between (1)O(2) and d(6)-tetramethylethylene. The minimum energy path on the potential energy surface for this process reaches a valley-ridge inflection point and then bifurcates leading to the two final products. Using canonical variational transition state theory, two distinct dynamical bottlenecks were located corresponding to the H- and the D-abstraction, respectively. The calculated KIE at 263 K turns out to be 1.126. Analogously, a H/T KIE of 1.17 at the same temperature has been found for the reaction of (1)O(2) with the tritiated derivative of tetramethylethylene.
变分过渡态理论已被用于计算影响（1）O（2）与d（6）-四甲基乙烯反应中产物比例的动力学同位素效应。该过程在势能面上的最小能量路径到达一个谷脊拐点，然后分叉形成两种最终产物。使用正则变分过渡态理论，分别找到了对应于氢和氘提取的两个不同的动力学瓶颈。在263 K下计算得到的动力学同位素效应为1.126。类似地，对于（1）O（2）与四甲基乙烯的氚代衍生物的反应，在相同温度下发现氢/氚动力学同位素效应为1.17。
