Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 194021 St. Petersburg, Russia.
J Chem Phys. 2013 Jun 28;138(24):244302. doi: 10.1063/1.4809992.
The quantum mechanical approach to vector correlation of angular momentum orientation and alignment in chemical reactions [G. Balint-Kurti and O. S. Vasyutinskii, J. Phys. Chem. A 113, 14281 (2009)] is applied to the molecular reagents and products of the Li + HF [L. Gonzalez-Sanchez, O. S. Vasyutinskii, A. Zanchet, C. Sanz-Sanz, and O. Roncero, Phys. Chem. Chem. Phys. 13, 13656 (2011)] and F + HD [D. De Fazio, J. Lucas, V. Aquilanti, and S. Cavalli, Phys. Chem. Chem. Phys. 13, 8571 (2011)] reactions for which accurate scattering information has become recently available through time-dependent and time-independent approaches. Application of the theory to two important particular cases of the reactive collisions has been considered: (i) the influence of the angular momentum polarization of reactants in the entrance channel on the spatial distribution of the products in the exit channel and (ii) angular momentum polarization of the products of the reaction between unpolarized reactants. In the former case, the role of the angular momentum alignment of the reactants is shown to be large, particularly when the angular momentum is perpendicular to the reaction scattering plane. In the latter case, the orientation and alignment of the product angular momentum was found to be significant and strongly dependent on the scattering angle. The calculation also reveals significant differences between the vector correlation properties of the two reactions under study which are due to difference in the reaction mechanisms. In the case of F + HD reaction, the branching ratio between HF and DF production points out interest in the insight gained into the detailed dynamics, when information is available either from exact quantum mechanical calculations or from especially designed experiments. Also, the geometrical arrangement for the experimental determination of the product angular momentum orientation and alignment based on a compact and convenient spherical tensor expression for the intensity of the resonance enhanced multiphoton ionization (REMPI 2 + 1) signal is suggested.
化学反应中角动量取向和定向的量子力学关联方法[G. Balint-Kurti 和 O. S. Vasyutinskii，J. Phys. Chem. A 113, 14281 (2009)]被应用于 Li + HF[L. Gonzalez-Sanchez、O. S. Vasyutinskii、A. Zanchet、C. Sanz-Sanz 和 O. Roncero，Phys. Chem. Chem. Phys. 13, 13656 (2011)]和 F + HD[D. De Fazio、J. Lucas、V. Aquilanti 和 S. Cavalli，Phys. Chem. Chem. Phys. 13, 8571 (2011)]反应的分子试剂和产物，这些反应的准确散射信息最近通过时间相关和时间无关的方法变得可用。该理论已应用于两个重要的反应碰撞特殊情况：（i）反应物在进入通道中的角动量极化对产物在出口通道中的空间分布的影响；（ii）非极化反应物之间反应产物的角动量极化。在前一种情况下，表明反应物角动量的取向和定向作用很大，特别是当角动量垂直于反应散射平面时。在后一种情况下，发现产物角动量的取向和定向很重要，并且强烈依赖于散射角。计算还揭示了两个被研究反应的矢量关联特性之间的显著差异，这是由于反应机制的不同。在 F + HD 反应的情况下，HF 和 DF 生成之间的分支比表明，当可以从精确的量子力学计算或专门设计的实验中获得信息时，深入了解详细动力学是有意义的。此外，还建议了一种基于紧凑方便的球张量表达式的实验确定产物角动量取向和定向的几何布置，用于共振增强多光子电离（REMPI 2 + 1）信号的强度。
