Determination of accurate electron chiral asymmetries in fenchone and camphor in the VUV range: sensitivity to isomerism and enantiomeric purity

Abstract

Ivan (2016) Determination of accurate electron chiral asymmetries in fenchone and camphor in the VUV range: sensitivity to isomerism and enantiomeric purity. Physical Chemistry Chemical Physics . ISSN 1463-9084 Access from the University of Nottingham repository: http://eprints.nottingham.ac.uk/32734/1/PECD_PCCP2016_Accepted_manuscript.pdf Copyright and reuse:The Nottingham ePrints service makes this work by researchers of the University of Nottingham available open access under the following conditions. This article is made available under the University of Nottingham End User licence and may be reused according to the conditions of the licence. For more details see: http://eprints.nottingham.ac.uk/end_user_agreement.pdf A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk This is an Accepted Manuscript, which has been through the Royal Society of Chemistry peer review process and has been accepted for publication.Accepted Manuscripts are published online shortly after acceptance, before technical editing, formatting and proof reading. Using this free service, authors can make their results available to the community, in citable form, before we publish the edited article. We will replace this Accepted Manuscript with the edited and formatted Advance Article as soon as it is available.You can find more information about Accepted Manuscripts in the Information for Authors.Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. Photoelectron circular dichroism (PECD) manifests itself as an intense forward/backward asymmetry in the angular distribution of photoelectrons produced from randomly--oriented enantiomers by photoionization with circularly--polarized light (CPL). As a sensitive probe of both photoionization dynamics and of the chiral molecular potential, PECD attracts much interest especially with the recent performance of related experiments with visible and VUV laser sources. Here we report, by use of quasi--perfect CPL VUV synchrotron radiation and using a double imaging photoelectron/photoion coincidence (i 2 PEPICO) spectrometer, new and very accurate values of the corresponding asymmetries on showcase chiral isomers: camphor and fenchone. These data have additionally been normalized to the absolute enantiopurity of the sample as measured by a chromatographic technique. They can therefore be used as benchmarking data for new PECD experiments, as well as for theoretical models. In particular we found, especially for the outermost orbital of both molecules, a good agreement with CMS--Xα PECD modeling over the whole VUV range. We also report a spectacular sensitivity of PECD to isomerism for slow electrons, ...

Emitter-site-selective photoelectron circular dichroism of trifluoromethyloxirane

“…It was also noticed that PECD changes with the binding energy of a system, i.e., it is different for the ionization of different molecular orbitals [2]. Furthermore, a strong dependence of PECD on the photoelectron kinetic energy (exciting-photon energy) was found experimentally and theoretically for outer-shell photoionization of methyloxirane [7][8][9], chiral derivates of oxirane [10], as well as camphor and fenchone [11][12][13].…”

Identifying and Understanding Strong Vibronic Interaction Effects Observed in the Asymmetry of Chiral Molecule Photoelectron Angular Distributions

“…We comment that a general advantage of PECD has been shown in its ability to reveal underlying orbital electronic structure even in spectrally congested regions where individual orbitals are not resolved in the PES. [39,[47][48][49] This arises because there may often be large variations in b 1 (in magnitude and sign) between adjacent orbitals even while the cross sections are quite commensurate -with consequently little distinguishable variation in intensity of the regular spectrum. In a somewhat similar manner, PECD may here provide clues to the position of vibrational transitions, even when these are too weak and the resolution insufficient, to show as significant structure in the PES alone.…”

Circular Dichroism in Multiphoton Ionization of Resonantly ExcitedHe+Ions

“…In earlier works (e.g., refs. [6][7][8][9][10][11][12][13][14] and references therein), the study of CD in photoelectron angular distributions revealed detailed information on atomic and molecular ionization, including the realization of a complete experiment, i.e., the determination of the photoionization amplitudes and their phases.…”