Direct observation of vibrational energy dispersal: Via methyl torsions

Gardner, Adrian M.; Tuttle, William D.; Whalley, Laura E.; Wright, Timothy G.

Abstract

© 2018 The Royal Society of Chemistry. Explicit evidence for the role of methyl rotor levels in promoting energy dispersal is reported. A set of coupled zero-order vibration/vibration-torsion (vibtor) levels in the S1 state of para-fluorotoluene (pFT) are investigated. Two-dimensional laser-induced fluorescence (2D-LIF) and two-dimensional zero-kinetic-energy (2D-ZEKE) spectra are reported, and the assignment of the main features in both sets of spectra reveals that the methyl torsion is instrumental in providing a route for coupling between vibrational levels of different symmetry classes. We find that there is very localized, and selective, dissipation of energy via doorway states, and that, in addition to an increase in the density of states, a critical role of the methyl group is a relaxation of symmetry constraints compared to direct vibrational coupling.

Citation

Gardner, A. M., Tuttle, W. D., Whalley, L. E., & Wright, T. G. (2018). Direct observation of vibrational energy dispersal: Via methyl torsions. Chemical Science, 9(8), 2270-2283. https://doi.org/10.1039/c7sc05309f

• Journal Article Type: Article
• Acceptance Date: Jan 24, 2018
• Online Publication Date: Jan 24, 2018
• Publication Date: Jan 1, 2018
• Deposit Date: Jan 25, 2018
• Publicly Available Date: Jan 25, 2018
• Journal: Chemical Science
• Print ISSN: 2041-6520
• Electronic ISSN: 2041-6539
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 8
• Pages: 2270-2283
• DOI: https://doi.org/10.1039/c7sc05309f
• Public URL: https://nottingham-repository.worktribe.com/output/906830
• Publisher URL: http://pubs.rsc.org/en/Content/ArticleLanding/2018/SC/C7SC05309F#!divAbstract