Scattering-angle resolved product rotational alignment for the reaction of Cl with vibrationally excited methane

Abstract

State-to-state dynamics of the Cl + CH 3 OH → HCl + CH 2 OH reactionWe have applied the experimental technique of core extraction ͓W. R. Simpson et al., J. Chem. Phys. 103, 7299 ͑1995͔͒ combined with resonance-enhanced multiphoton ionization ͑REMPI͒ with a polarized laser beam to probe the angular-momentum alignment of the HCl product of the reaction of Cl with vibrationally excited CH 4 ( 3 ϭ1). The core extraction method permits us to distinguish products scattered in different directions in the center-of-mass frame, and thus we are able to determine the rotational alignment for various product scattering angles for individual HCl(vЈ,JЈ) quantum states ͑a state-resolved three-vector correlation͒. For the forward-scattered HCl͑vЈϭ1, JЈϭ1͒ we observe a large positive rotational alignment. This positive velocity-angular-momentum correlation is interpreted to be the result of the angular momentum of the HCl product being directed in the plane perpendicular to the line-of-centers force in a simple hard-sphere scattering model.

Product rotational polarization: Stereodynamics of the reaction Cl(2P3/2)+CD4(v=0,j=0)→DCl(v′=0,j′=1)+CD3

“…[20][21][22] The enhanced reagent number densities achieved using these techniques, compared with those typically obtained in conventional crossed-molecular beam methods, have now enabled full state-to-state differential cross sections to be measured for the ClϩCH 4 reaction. [16][17][23][24][25] Blais and Truhlar 26 and Han et al 27 have studied the alignment of the product rotational angular momentum as a function of scattering angle using quasiclassical-trajectory Legendre moment method and provided many new and valuable results. Recently, Zare and co-workers 28 have applied the experimental technique of core extraction combined with resonance-enhanced multiphoton ionization ͑REMPI͒ with a polarized laser beam to probe the angular-momentum alignment of the DCl product of the reaction of Cl with CD 4 .…”

Velocity map imaging the dynamics of the reactions of Cl atoms with neopentane and tetramethylsilane

“…Cl + C 2 H 6 → C 2 H 5 + HCl (4) have been well studied both experimentally 17,18,22,[25][26][27]45 and computationally, [57][58][59][60][61] and the reactions of Cl atoms with propane 1,62-64 and n-butane 21,25,62 have been similarly investigated. The energetics and kinetics of these reactions are very similar to those for reactions (2) and (3); the reactions are all rapid and direct, have either a low or no barrier to reaction and the exothermicities of the primary hydrogen abstraction reactions are typically about -3 kcal mol -1 .…”

Theoretical studies of product polarization and state distributions of the H+HCl reaction

“…Since the pioneering work of Fano and Macek [1], Herschbach and coworkers [2] and of Blais and Truhlar [3], substantial progress has been made during the past several years in the field of chemical reaction stereodynamics . With the development in new experimental techniques, such as laser-induced chemiluminescence [8], polarized laser-induced fluorescence [9], core extraction combined with resonance-enhanced multiphoton ionization (RE-MPI) [10,11], and doppler resolved laser-induced fluorescence [12,13], it is becoming increasingly Chemical Physics 283 (2002) [463][464][465][466][467][468][469][470][471][472] www.elsevier.com/locate/chemphys clear that product rotational polarization can provide detailed mechanistic information. One important step in the theoretical progress is the introduction of the concept of polarization dependent differential cross-sections (PDDCSs) by Shafer-Ray et al [14].…”