Far-IR absorption of neutral polycyclic aromatic hydrocarbons (PAHs): light on the mechanism of IR–UV ion dip spectroscopy
| Autor: | Sébastien Gruet, Sanjana Panchagnula, Wybren Jan Buma, Alexander K. Lemmens, Johannes M. M. Thunnissen, Melanie Schnell, Daniël B. Rap, Anouk M. Rijs, Alexander G. G. M. Tielens, Amanda L. Steber |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
FELIX Condensed Matter Physics
FELIX Molecular Structure and Dynamics Letter Materials science 010304 chemical physics Anharmonicity Infrared spectroscopy FELIX Infrared and Terahertz Spectroscopy 010402 general chemistry Photochemistry 01 natural sciences Spectral line 0104 chemical sciences Ion Delocalized electron Ionization 0103 physical sciences Molecule ddc:530 General Materials Science Physical and Theoretical Chemistry Spectroscopy |
| Zdroj: | The journal of physical chemistry letters 11(21), 8997-9002 (2020). doi:10.1021/acs.jpclett.0c02714 The Journal of Physical Chemistry Letters Journal of Physical Chemistry Letters, 11(21), 8997–9002 Journal of Physical Chemistry Letters, 11, 8997-9002 Journal of Physical Chemistry Letters, 11, 21, pp. 8997-9002 J. Phys. Chem. Lett. |
| ISSN: | 1948-7185 |
| DOI: | 10.1021/acs.jpclett.0c02714 |
| Popis: | The journal of physical chemistry letters 11(21), 8997 - 9002 (2020). doi:10.1021/acs.jpclett.0c02714 Gas-phase IR–UV double-resonance laser spectroscopy is an IR absorption technique that bridges the gap between experimental IR spectroscopy and theory. The IR experiments are used to directly evaluate predicted frequencies and potential energy surfaces as well as to probe the structure of isolated molecules. However, a detailed understanding of the underlying mechanisms is, especially in the far-IR regime, still far from complete, even though this is crucial for properly interpreting the recorded IR absorption spectra. Here, events occurring upon excitation to vibrational levels of polycyclic aromatic hydrocarbons by far-IR radiation from the FELIX free electron laser are followed using resonance-enhanced multiphoton ionization spectroscopy. These studies provide detailed insight into how ladder climbing and anharmonicity influence IR–UV spectroscopy and therefore the resulting IR signatures in the far-IR region. Moreover, the potential energy surfaces of these low-frequency delocalized modes are investigated and shown to have a strong harmonic character. Published by ACS, Washington, DC |
| Databáze: | OpenAIRE |
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