Vibrationally-resolved photoelectron spectroscopy and photoelectron circular dichroism of bicyclic monoterpene enantiomers
Autor: | Rim Hadidi, Hassan Ganjitabar, Gustavo García, Laurent Nahon, Ivan Powis |
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Rok vydání: | 2018 |
Předmět: |
chemistry.chemical_classification
Circular dichroism Double bond Bicyclic molecule Monoterpene Binding energy 02 engineering and technology Photoionization 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics 0104 chemical sciences Crystallography chemistry X-ray photoelectron spectroscopy Molecule Physical and Theoretical Chemistry 0210 nano-technology Spectroscopy |
Zdroj: | Journal of Molecular Spectroscopy |
ISSN: | 0022-2852 |
Popis: | The photoionization of four chiral bicyclic monoterpene isomers, α-pinene, β-pinene, 3-carene and sabinene — all commonly found constituents in essential natural oils — has been studied using synchrotron radiation and compared to recent findings for the cyclic isomer limonene. Slow photoelectron spectra (SPES) are recorded between threshold and an energy of 10.5 eV. In the case of limonene, α-pinene, and 3-carene, vibrational structure is observed in the ground ionic state and attributed to a C C double bond stretching in the cation, using Franck-Condon vibrational band simulations. The photoelectron circular dichroism (PECD) is examined for specific enantiomers of these terpenes, and vibrational modification of the forward-backward photoelectron asymmetry detected by PECD can be tentatively identified, even when the corresponding SPES is unstructured. Large chiral asymmetry factors are found at low binding energies for the pinenes and 3-carene, with α-pinene in particular displaying a 37% forward-backward photoelectron asymmetry, believed to be a record chiroptical asymmetry for randomly-oriented, non-interacting molecules. |
Databáze: | OpenAIRE |
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