Angular momenta correlation in kinematically constrained reactions: application to the Ba + HI → BaI + H system

Albertı́, M.; Giménez, Xavier; Aguilar, Antonio; Ureña, A. González

doi:10.1080/00268979500101581

Cited by 7 publications

(2 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These simulations, however, were performed to provide a comparison with the crossed-beam work of Vaccaro et al 18 and, consequently, no emphasis was placed on the low collision energy regime. A recent quasiclassical trajectory calculation study by Albertí et al 48 investigated angular momentum vector correlations for this reaction system and focused its attention on the channeling of reagent rotational angular momentum into product orbital angular momentum. These results, however, cannot be directly compared with our experimental findings for vϭ0,1,2, which involve much larger impact parameters.…”

Section: Discussionmentioning

confidence: 99%

Energy and angular momentum control of the specific opacity functions in the Ba+HI→BaI+H reaction

Kalogerakis

Zare

1996

The Journal of Chemical Physics

View full text Add to dashboard Cite

Vibration-rotation excitation of CO by hot hydrogen atoms: Comparison of two potential energy surfacesCrossed-beam and beam-gas experiments on the reaction BaϩHI→BaIϩH have been performed, in which the most probable collision energy ranges from 3 to 17 kcal/mol. The results, combined with previous experimental studies on this reaction system, show a remarkable collision energy dependence. Between low and high collision energies, a transition occurs in the intensity, width, and peak location of the product vibrational and rotational population distributions. The onset of this transition is estimated to occur at approximately 5 kcal/mol. For collision energies smaller than 5 kcal/mol, the product vibrational distribution is bell shaped and peaks at vϭ12. For collision energies larger than 5 kcal/mol, a second maximum appears at vϭ0 in the vibrational distribution. The rotational distributions of the crossed-beam experiments are extremely narrow but broaden at lower collision energies. As the collision energy is increased above 5 kcal/mol, the BaI rotational excitation is very near the energetic limit, and the maximum for the BaI͑vϭ0͒ rotational population distribution moves from Jϭ415.5 to Jϭ538.5. In contrast, below the transition onset, the maximum remains unchanged around Jϭ420.5. Moreover, the peaks of the BaI͑vϭ1͒ and BaI͑vϭ2͒ rotational distributions appear at successively lower J values, as expected from energy conservation arguments. The nature of the kinematic constraints for this reaction allows the determination of the opacity functions for the production of the BaI product in a specific vibrational level v. Detailed analysis of the collision energy dependence of the specific opacity functions offers insight into the role of conservation of energy and angular momentum in influencing this reaction. At low collision energies, the maximum reactive impact parameter, b max , is determined by an angular momentum ͑centrifugal͒ barrier. At collision energies larger than 5 kcal/mol, conservation of energy dictates the value of b max . These two processes are identified as the mechanisms that control the BaϩHI reaction cross section. The transition between the two mechanisms provides an interpretation for the bimodal character of the BaI product internal-state distribution.

show abstract

Section: Discussionmentioning

confidence: 99%

Energy and angular momentum control of the specific opacity functions in the Ba+HI→BaI+H reaction

Kalogerakis

Zare

1996

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…This is in agreement with the present QCT results. This kind of dependence can be used as an indicator of product orbital angular momentum constancy, being the basis for the constant product orbital angular momentum (CPOAM) model. − This model, in turn, leads to a simplified way of calculating the rotational alignments. They describe the orientation of the rotational angular momentum vector J ‘ with respect to the initial velocity vector k , being usually given as the Legendre second moment P 2 〈 J ‘· k 〉 of the products angular distribution.…”

Section: Resultsmentioning

confidence: 99%

Dynamics of Excited Rare-Gas Atoms with Halide Molecules: The Ar(³P) + ClF → ArCl* + F, ArF* + Cl Reaction

et al. 2000

Self Cite

View full text Add to dashboard Cite

The product species originating from the interaction between metastable Ar atoms and the ClF molecules were studied using theoretical (structure and dynamics) methods. Quasiclassical trajectory calculations were carried out on an analytical, monovalued potential energy surface. The energy surface was obtained by means of a fit to CIS (UHF) ab initio points calculated for a set of relevant triatomic configurations, adequately connected to assume that the reaction takes place adiabatically. Cross sections, rate constants, and products' energy disposal for both ArCl* and ArF* excimer formation were calculated, showing a dominancy of the less stable ArCl* + F channel. In addition, angular distributions and rotational alignments for both product channels were analyzed. The influence of reactant internal excitation on integral cross sections and product energy distributions was also studied, considering a wide range of initial rovibrational levels. A remarkable enhancing effect of the reactant rotation was found, as compared to vibration, for the ArCl* product, whereas the opposite trend is observed for the ArF* channel. Whenever possible, the observed behavior was related to both HHL and HLH kinematical considerations. The effect of rotational excitation was used as well to elucidate the angular momentum transfer mechanism among the two competing reaction channels. The role of a relevant rotation-orbiting coupling was identified. Results are found to be, overall, in agreement with the available experimental information, for the title reaction as well as other related systems. This indicates that the fundamental assumption of the present work, namely that the reaction proceeds on a single excited adiabatic potential surface, is accurate enough to account for the main trends of the reaction dynamics.

show abstract

Low-energy stereodynamics in the ion–molecule reactions D+ + D2/HD and H+ + H2/HD: reagent vibrational excitation effect and mass factor effect

Lü

2018

Theor Chem Acc

View full text Add to dashboard Cite

Angular momenta correlation in kinematically constrained reactions: application to the Ba + HI → BaI + H system

Cited by 7 publications

References 25 publications

Energy and angular momentum control of the specific opacity functions in the Ba+HI→BaI+H reaction

Energy and angular momentum control of the specific opacity functions in the Ba+HI→BaI+H reaction

Dynamics of Excited Rare-Gas Atoms with Halide Molecules: The Ar(³P) + ClF → ArCl* + F, ArF* + Cl Reaction

Low-energy stereodynamics in the ion–molecule reactions D+ + D2/HD and H+ + H2/HD: reagent vibrational excitation effect and mass factor effect

Contact Info

Product

Resources

About

Angular momenta correlation in kinematically constrained reactions: application to the Ba + HI → BaI + H system

Cited by 7 publications

References 25 publications

Energy and angular momentum control of the specific opacity functions in the Ba+HI→BaI+H reaction

Energy and angular momentum control of the specific opacity functions in the Ba+HI→BaI+H reaction

Dynamics of Excited Rare-Gas Atoms with Halide Molecules: The Ar(3P) + ClF → ArCl* + F, ArF* + Cl Reaction

Low-energy stereodynamics in the ion–molecule reactions D+ + D2/HD and H+ + H2/HD: reagent vibrational excitation effect and mass factor effect

Contact Info

Product

Resources

About

Dynamics of Excited Rare-Gas Atoms with Halide Molecules: The Ar(³P) + ClF → ArCl* + F, ArF* + Cl Reaction