Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions
Electron-ion coincidence imaging is used to study chiral asymmetry in the angular distribution of electrons emitted from randomly-oriented enantiomers of two molecules, methyloxirane and trifluoromethyloxirane, upon ionization by circularly polarized VUV synchrotron radiation. Vibrationally-resolved...
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Wiley-VCH
2017
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| Online Access: | https://eprints.nottingham.ac.uk/39389/ |
| _version_ | 1848795825704009728 |
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| author | Garcia, Gustavo A. Dossmann, Heloise Nahon, Laurent Daly, Steven Powis, Ivan |
| author_facet | Garcia, Gustavo A. Dossmann, Heloise Nahon, Laurent Daly, Steven Powis, Ivan |
| author_sort | Garcia, Gustavo A. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Electron-ion coincidence imaging is used to study chiral asymmetry in the angular distribution of electrons emitted from randomly-oriented enantiomers of two molecules, methyloxirane and trifluoromethyloxirane, upon ionization by circularly polarized VUV synchrotron radiation. Vibrationally-resolved photoelectron circular dichroism (PECD) measurements of the outermost orbital ionization reveal unanticipated large fluctuations in the magnitude of the forward-backward electron scattering asymmetry, including even a complete reversal of direction. Identification and assignment of the vibrational excitations is supported by Franck-Condon simulations of the photoelectron spectra. A previously proposed quasi-diatomic model for PECD is developed and extended to treat polyatomic systems. The parametric dependence of the electronic dipole matrix elements on nuclear geometry is evaluated in the adiabatic approximation, and provokes vibrational level dependent shifts in amplitude and phase, to which the chiral photoelectron angular distributions are especially sensitive. It is shown that single quantum excitation of those vibrational modes which experience only a relatively small displacement of the ion equilibrium geometry along the normal coordinate, and which are then only weakly excited in the Franck-Condon limit, can be accompanied by big shifts in scattering phase; hence the observed big fluctuations in PECD asymmetry for such modes. |
| first_indexed | 2025-11-14T19:38:15Z |
| format | Article |
| id | nottingham-39389 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:38:15Z |
| publishDate | 2017 |
| publisher | Wiley-VCH |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-393892020-05-04T18:29:48Z https://eprints.nottingham.ac.uk/39389/ Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions Garcia, Gustavo A. Dossmann, Heloise Nahon, Laurent Daly, Steven Powis, Ivan Electron-ion coincidence imaging is used to study chiral asymmetry in the angular distribution of electrons emitted from randomly-oriented enantiomers of two molecules, methyloxirane and trifluoromethyloxirane, upon ionization by circularly polarized VUV synchrotron radiation. Vibrationally-resolved photoelectron circular dichroism (PECD) measurements of the outermost orbital ionization reveal unanticipated large fluctuations in the magnitude of the forward-backward electron scattering asymmetry, including even a complete reversal of direction. Identification and assignment of the vibrational excitations is supported by Franck-Condon simulations of the photoelectron spectra. A previously proposed quasi-diatomic model for PECD is developed and extended to treat polyatomic systems. The parametric dependence of the electronic dipole matrix elements on nuclear geometry is evaluated in the adiabatic approximation, and provokes vibrational level dependent shifts in amplitude and phase, to which the chiral photoelectron angular distributions are especially sensitive. It is shown that single quantum excitation of those vibrational modes which experience only a relatively small displacement of the ion equilibrium geometry along the normal coordinate, and which are then only weakly excited in the Franck-Condon limit, can be accompanied by big shifts in scattering phase; hence the observed big fluctuations in PECD asymmetry for such modes. Wiley-VCH 2017-01-23 Article PeerReviewed Garcia, Gustavo A., Dossmann, Heloise, Nahon, Laurent, Daly, Steven and Powis, Ivan (2017) Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions. ChemPhysChem, 18 (5). pp. 500-512. ISSN 1439-7641 http://onlinelibrary.wiley.com/doi/10.1002/cphc.201601250/abstract doi:10.1002/cphc.201601250R1 doi:10.1002/cphc.201601250R1 |
| spellingShingle | Garcia, Gustavo A. Dossmann, Heloise Nahon, Laurent Daly, Steven Powis, Ivan Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| title | Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| title_full | Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| title_fullStr | Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| title_full_unstemmed | Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| title_short | Identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| title_sort | identifying and understanding strong vibronic interaction effects observed in the asymmetry of chiral molecule photoelectron angular distributions |
| url | https://eprints.nottingham.ac.uk/39389/ https://eprints.nottingham.ac.uk/39389/ https://eprints.nottingham.ac.uk/39389/ |