Jambrina P G, Aldegunde J, Aoiz F J, Sneha M, Zare R N
Departamento de Química Física I , Facultad de Química , Universidad Complutense de Madrid , 28040 , Spain . Email:
Departamento de Química Física , Universidad de Salamanca , Salamanca , Spain.
Chem Sci. 2016 Jan 1;7(1):642-649. doi: 10.1039/c5sc03373j. Epub 2015 Oct 5.
Differential cross sections (DSCs) of the HD(', ') product for the reaction of H atoms with supersonically cooled D molecules in a small number of initial rotational states have been measured at a collision energy of 1.97 eV. These DCSs show an oscillatory pattern that results from interferences caused by different dynamical scattering mechanisms leading to products scattered into the same solid angle. The interferences depend on the initial rotational state of the D( = 0, ) reagent and diminish in strength with increasing rotation. We present here a detailed explanation for this behavior and how each dynamical scattering mechanism has a dependence on the helicity Ω, the projection of the initial rotational angular momentum of the D reagent on the approach direction. Each helicity corresponds to a different internuclear axis distribution, with the consequence that the dependence on Ω reveals the preference of the different quasiclassical mechanisms as a function of approach direction. We believe that these results are general and will appear in any reaction for which several mechanisms are operative.
在碰撞能量为1.97电子伏特的条件下，测量了处于少量初始转动状态的超音速冷却D分子与H原子反应生成HD（'，'）产物的微分截面（DSC）。这些微分截面呈现出一种振荡模式，该模式是由不同动力学散射机制导致产物散射到同一立体角时产生的干涉所引起的。干涉取决于D（ = 0， ）试剂的初始转动状态，并且随着转动增加，干涉强度减弱。我们在此给出对此行为的详细解释，以及每种动力学散射机制如何依赖于螺旋度Ω，即D试剂初始转动角动量 在接近方向上的投影。每个螺旋度对应于不同的核间轴分布，结果是对Ω的依赖揭示了不同准经典机制作为接近方向函数的偏好。我们认为这些结果具有普遍性，并且会出现在任何有多种机制起作用的反应中。
