论文标题
使用半经典激体理论研究的经典反应路径和隧道路径的比较
Comparison of classical reaction paths and tunneling paths studied with the semiclassical instanton theory
论文作者
论文摘要
使用Instanton理论研究了2,4,6-三丁基苯基自由基至3,5-DI-di-tERT叔丁基基因的原子原子转移反应至3,5-DI-di-tert叔丁基基因，该反应具有短但强弯曲的反应路径。我们发现，隧道的路径是从定性偏离经典的内在反应坐标，这是大规模加权笛卡尔坐标中最陡峭的路径。为了进行该比较，我们实现了预测器 - 校正算法的新变体，以计算固有反应坐标。我们使用反作用力分析方法作为将反应屏障分解为结构和电子成分的手段。由于狭窄的能量障碍，原子隧道在上述反应中甚至高于室温都很重要。我们计算出的速率常数在350 K和100 K之间与实验值非常吻合。我们发现在100 k处的H/D动力学同位素效应。隧道在400 K以下的protium转移占主导地位，氘转移在300 K以下。我们比较了隧道路径的长度以及在反应HCl + Cl中氢原子转移的经典路径，并在此反应中量化了该反应的角度。在低温下，隧道路径比经典路径短约40％。
Atom tunneling in the hydrogen atom transfer reaction of the 2,4,6-tri-tert-butylphenyl radical to 3,5-di-tert-butylneophyl, which has a short but strongly curved reaction path, was investigated using instanton theory. We found the tunneling path to deviate qualitatively from the classical intrinsic reaction coordinate, the steepest-descent path in mass-weighted Cartesian coordinates. To perform that comparison, we implemented a new variant of the predictor-corrector algorithm for the calculation of the intrinsic reaction coordinate. We used the reaction force analysis method as a means to decompose the reaction barrier into structural and electronic components. Due to the narrow energy barrier, atom tunneling is important in the abovementioned reaction, even above room temperature. Our calculated rate constants between 350 K and 100 K agree well with experimental values. We found a H/D kinetic isotope effect of almost 106 at 100 K. Tunneling dominates the protium transfer below 400 K and the deuterium transfer below 300 K. We compared the lengths of the tunneling path and the classical path for the hydrogen atom transfer in the reaction HCl + Cl and quantified the corner cutting in this reaction. At low temperature, the tunneling path is about 40% shorter than the classical path.
