Roaming dynamics in ketene isomerization

Frederic A. L. Mauguiere, Peter Collins, Gregory S. Ezra, Stavros C. Farantos, Stephen Wiggins*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

15 Citations (Scopus)

Abstract

A reduced two-dimensional model is used to study ketene isomerization reaction. In light of recent results by Ulusoy et al. (J Phys Chem A 117, 7553, 2013), the present work focuses on the generalization of the roaming mechanism to the ketene isomerization reaction by applying our phase space approach previously used to elucidate the roaming phenomenon in ion-molecule reactions. Roaming is again found be associated with the trapping of trajectories in a phase space region between two dividing surfaces; trajectories are classified as reactive or nonreactive, and are further naturally classified as direct or nondirect (roaming). The latter long-lived trajectories are trapped in the region of nonlinear mechanical resonances, which in turn define alternative reaction pathways in phase space. It is demonstrated that resonances associated with periodic orbits provide a dynamical explanation of the quantum mechanical resonances found in the isomerization rate constant calculations by Gezelter and Miller (J Chem Phys 103, 7868-7876, 1995). Evidence of the trapping of trajectories by 'sticky' resonant periodic orbits is provided by plotting Poincar, surfaces of section, and a gap time analysis is carried out in order to investigate the statistical assumption inherent in transition state theory for ketene isomerization.

Original languageEnglish
Article number1507
Number of pages13
JournalTheoretical Chemistry Accounts
Volume133
Issue number7
DOIs
Publication statusPublished - 10 Jun 2014

Keywords

  • Roaming reaction
  • Normally hyperbolic invariant manifold
  • Periodic orbit
  • Nonlinear resonance
  • Transition state and dividing surface
  • Gap time distribution
  • TRANSITION-STATE THEORY
  • UNIMOLECULAR REACTIONS
  • TRAPPED TRAJECTORIES
  • WOLFF REARRANGEMENT
  • DISSOCIATION RATES
  • CLASSICAL THEORIES
  • ENERGY-DEPENDENCE
  • REACTION-PATH
  • COLLISIONS
  • MODEL

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Cite this

Mauguiere, F. A. L., Collins, P., Ezra, G. S., Farantos, S. C., & Wiggins, S. (2014). Roaming dynamics in ketene isomerization. Theoretical Chemistry Accounts, 133(7), [1507]. https://doi.org/10.1007/s00214-014-1507-4