Laboratory spectroscopy and astronomical significance of the fully-benzenoid PAH triphenylene and its cation
Triphenylene (C18H12) is a highly symmetric polycyclic aromatic hydrocarbon (PAH) molecule with a ‘fully-benzenoid’ electronic structure. This confers a high chemical stability compared with PAHs of similar size. Although numerous infrared and UV-visible experimental spectroscopic and theoretical st...
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Elsevier
2017
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| Online Access: | https://eprints.nottingham.ac.uk/42766/ |
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| author | Kofman, V. Sarre, Peter Hibbins, R.E. ten Kate, I.L. Linnartz, H. |
| author_facet | Kofman, V. Sarre, Peter Hibbins, R.E. ten Kate, I.L. Linnartz, H. |
| author_sort | Kofman, V. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Triphenylene (C18H12) is a highly symmetric polycyclic aromatic hydrocarbon (PAH) molecule with a ‘fully-benzenoid’ electronic structure. This confers a high chemical stability compared with PAHs of similar size. Although numerous infrared and UV-visible experimental spectroscopic and theoretical studies of a wide range PAHs in an astrophysical context have been conducted, triphenylene and its radical cation have received almost no attention. There exists a huge body of spectroscopic evidence for neutral and ionised PAHs in astrophysical sources, obtained principally through detection of infrared emission features that are characteristic of PAHs as a chemical class. However, it has so far not proved possible to identify spectroscopically a single isolated PAH in space, although PAHs including triphenylene have been detected mass spectrometrically in meteorites. In this work we focus on recording laboratory electronic spectra of neutral and ionised triphenylene between 220 and 780 nm, trapped in H2O ice and solid argon at 12 K. The studies are motivated by the potential for spectroscopic astronomical detection of electronic absorption spectra of PAHs in ice mantles on interstellar grains as discussed by Linnartz (2014), and were undertaken also in a cold Ar matrix to provide guidance as to whether triphenylene (particularly in its singly positively ionised form) could be a viable candidate for any of the unidentified diffuse interstellar absorption bands. Based on the argon-matrix experimental results, comparison is made with previously unpublished astronomical spectra near 400 nm which contain broad interstellar absorption features consistent with the predictions from the laboratory matrix spectra, thus providing motivation for the recording of gas-phase electronic spectra of the internally cold triphenylene cation. |
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| id | nottingham-42766 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T19:49:57Z |
| publishDate | 2017 |
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| spelling | nottingham-427662018-04-24T15:40:34Z https://eprints.nottingham.ac.uk/42766/ Laboratory spectroscopy and astronomical significance of the fully-benzenoid PAH triphenylene and its cation Kofman, V. Sarre, Peter Hibbins, R.E. ten Kate, I.L. Linnartz, H. Triphenylene (C18H12) is a highly symmetric polycyclic aromatic hydrocarbon (PAH) molecule with a ‘fully-benzenoid’ electronic structure. This confers a high chemical stability compared with PAHs of similar size. Although numerous infrared and UV-visible experimental spectroscopic and theoretical studies of a wide range PAHs in an astrophysical context have been conducted, triphenylene and its radical cation have received almost no attention. There exists a huge body of spectroscopic evidence for neutral and ionised PAHs in astrophysical sources, obtained principally through detection of infrared emission features that are characteristic of PAHs as a chemical class. However, it has so far not proved possible to identify spectroscopically a single isolated PAH in space, although PAHs including triphenylene have been detected mass spectrometrically in meteorites. In this work we focus on recording laboratory electronic spectra of neutral and ionised triphenylene between 220 and 780 nm, trapped in H2O ice and solid argon at 12 K. The studies are motivated by the potential for spectroscopic astronomical detection of electronic absorption spectra of PAHs in ice mantles on interstellar grains as discussed by Linnartz (2014), and were undertaken also in a cold Ar matrix to provide guidance as to whether triphenylene (particularly in its singly positively ionised form) could be a viable candidate for any of the unidentified diffuse interstellar absorption bands. Based on the argon-matrix experimental results, comparison is made with previously unpublished astronomical spectra near 400 nm which contain broad interstellar absorption features consistent with the predictions from the laboratory matrix spectra, thus providing motivation for the recording of gas-phase electronic spectra of the internally cold triphenylene cation. Elsevier 2017-06-30 Article PeerReviewed application/pdf en cc_by_nc_nd https://eprints.nottingham.ac.uk/42766/1/PJS%20MOLAP_2017_Triphenylene_UoN.pdf Kofman, V., Sarre, Peter, Hibbins, R.E., ten Kate, I.L. and Linnartz, H. (2017) Laboratory spectroscopy and astronomical significance of the fully-benzenoid PAH triphenylene and its cation. Molecular Astrophysics, 7 . pp. 19-26. ISSN 2405-6758 Astrochemistry; Molecular processes; Methods: laboratory; techniques: spectroscopic; ISM: Molecules http://www.sciencedirect.com/science/article/pii/S2405675817300039 doi:10.1016/j.molap.2017.04.002 doi:10.1016/j.molap.2017.04.002 |
| spellingShingle | Astrochemistry; Molecular processes; Methods: laboratory; techniques: spectroscopic; ISM: Molecules Kofman, V. Sarre, Peter Hibbins, R.E. ten Kate, I.L. Linnartz, H. Laboratory spectroscopy and astronomical significance of the fully-benzenoid PAH triphenylene and its cation |
| title | Laboratory spectroscopy and astronomical significance of the
fully-benzenoid PAH triphenylene and its cation |
| title_full | Laboratory spectroscopy and astronomical significance of the
fully-benzenoid PAH triphenylene and its cation |
| title_fullStr | Laboratory spectroscopy and astronomical significance of the
fully-benzenoid PAH triphenylene and its cation |
| title_full_unstemmed | Laboratory spectroscopy and astronomical significance of the
fully-benzenoid PAH triphenylene and its cation |
| title_short | Laboratory spectroscopy and astronomical significance of the
fully-benzenoid PAH triphenylene and its cation |
| title_sort | laboratory spectroscopy and astronomical significance of the
fully-benzenoid pah triphenylene and its cation |
| topic | Astrochemistry; Molecular processes; Methods: laboratory; techniques: spectroscopic; ISM: Molecules |
| url | https://eprints.nottingham.ac.uk/42766/ https://eprints.nottingham.ac.uk/42766/ https://eprints.nottingham.ac.uk/42766/ |