Merkt Frédéric, Höveler Katharina, Deiglmayr Johannes
Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland.
J Phys Chem Lett. 2022 Jan 27;13(3):864-871. doi: 10.1021/acs.jpclett.1c03374. Epub 2022 Jan 19.
We present measurements of the product-channel branching ratios of the reactions (i) HD + HD forming HD + D (38.1(30)%) and HD + H (61.9(30)%), (ii) HD + D forming HD + D (61.4(35)%) and D + H (38.6(35)%), and (iii) D + HD forming HD+ D (60.5(20)%) and D + H (39.5(20)%) at collision energies near zero, i.e., below × 1 K. These branching ratios are compared with branching ratios predicted using three simple models: a combinatorial model (M1), a model (M2) describing the reactions as H-, H-, D-, and D-transfer processes, and a statistical model (M3) that relates the reaction rate coefficients to the translational and rovibrational state densities of the HD + H/D ( = 0, 1, 2 or 3) product channels. The experimental data are incompatible with the predictions of models M1 and M2 and reveal that the branching ratios exhibit clear correlations with the product state densities.
我们给出了反应（i）HD + HD生成HD + D（38.1(30)%）和HD + H（61.9(30)%）、（ii）HD + D生成HD + D（61.4(35)%）和D + H（38.6(35)%）以及（iii）D + HD生成HD + D（60.5(20)%）和D + H（39.5(20)%）在接近零的碰撞能量下，即低于×1 K时的产物通道分支比的测量结果。这些分支比与使用三种简单模型预测的分支比进行了比较：组合模型（M1）、将反应描述为H-、H-、D-和D-转移过程的模型（M2）以及将反应速率系数与HD + H/D（= 0、1、2或3）产物通道的平动和振转态密度相关联的统计模型（M3）。实验数据与模型M1和M2的预测不相符，并且表明分支比与产物态密度呈现明显的相关性。
