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Title: Nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 2 2 A (3 s ) Rydberg state: A four-dimensional quantum study

Authors:
 [1]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [1]
  1. Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
  2. Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1363703
Grant/Contract Number:
SC0015997
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 146; Journal Issue: 22; Related Information: CHORUS Timestamp: 2018-02-14 11:29:16; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Xie, Changjian, Malbon, Christopher, Yarkony, David R., and Guo, Hua. Nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 2 2 A (3 s ) Rydberg state: A four-dimensional quantum study. United States: N. p., 2017. Web. doi:10.1063/1.4985147.
Xie, Changjian, Malbon, Christopher, Yarkony, David R., & Guo, Hua. Nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 2 2 A (3 s ) Rydberg state: A four-dimensional quantum study. United States. doi:10.1063/1.4985147.
Xie, Changjian, Malbon, Christopher, Yarkony, David R., and Guo, Hua. 2017. "Nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 2 2 A (3 s ) Rydberg state: A four-dimensional quantum study". United States. doi:10.1063/1.4985147.
@article{osti_1363703,
title = {Nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 2 2 A (3 s ) Rydberg state: A four-dimensional quantum study},
author = {Xie, Changjian and Malbon, Christopher and Yarkony, David R. and Guo, Hua},
abstractNote = {},
doi = {10.1063/1.4985147},
journal = {Journal of Chemical Physics},
number = 22,
volume = 146,
place = {United States},
year = 2017,
month = 6
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 12, 2018
Publisher's Accepted Manuscript

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  • Photodissociation of hydroxymethyl (H{sub 2}COD) from the first excited state, a Rydberg 3s state, can produce either H+HCOD or H{sub 2}CO+D. These processes involve a seam of conical intersections. An analysis of the seam is reported based on a pointwise determination of the three gradient vectors that characterize a conical intersection: the energy difference gradient and the coupling gradient, which span the branching space, and the gradient of the average energy. These data are used to understand why H, but not D is produced at energies near threshold, the difference in the recoil anisotropy for H and D dissociation, andmore » whether H or D will be produced impulsively or after formation of an intermediate complex.« less
  • The photodissociation dynamics of methyl radical have been investigated at 193.3 nm using photofragment translational spectroscopy. The formation of CH[sub 2] and H([sup 2][ital S]) was the only dissociation pathway observed. Although it is not possible to assign the spin state of the methylene unambiguously, we believe that methylene is produced predominately in the [ital [tilde a]] [sup 1][ital A][sub 1] excited state. The translational energy distribution of the products is peaked at [similar to]13 kcal/mole which is consistent with the magnitude of the exit barrier on the excited state potential energy surface. The breadth of the distribution suggests thatmore » the methyl radicals dissociate from a wide range of geometries. From the photofragment angular distribution an anisotropy parameter of [beta]=[minus]0.9[plus minus]0.1 was determined.« less
  • The selectivity of the {alpha} C-Cl and {beta} C-Br bond fissions upon n{yields}{pi}* excitation of bromoacetyl chloride has been investigated with combined nonadiabatic Rice-Ramsperger-Kassel-Marcus theory and ab initio molecular dynamics calculations, which are based on the potential energy profiles calculated with the complete active space self-consistent field and multireference configuration interaction methods. The Zhu-Nakamura [J. Chem. Phys. 101, 10630 (1994); 102, 7448 (1995)] theory is chosen to calculate the nonadiabatic hopping probability. It is found that nonadiabatic effect plays an important role in determining selective dissociations of the C-Cl and C-Br bonds. The calculated rate constants are close to thosemore » from experimentally inferred values, but the branching ratio of the {alpha} C-Cl and {beta} C-Br bond fissions is different from the experimental findings. The direct molecular dynamics calculations predict that fission of the C-Cl bond occurs on a time scale of picoseconds and cleavage of the {beta} C-Br bond proceeds with less probability within the same period. This reveals that the initial relaxation dynamics is probably another important factor that influences the selectivity of the C-Cl and C-Br bond fissions in photodissociation of BrCH{sub 2}COCl at 248 nm.« less
  • No abstract prepared.