Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds
Abstract After decades of searching, astronomers have recently identified specific Polycyclic Aromatic Hydrocarbons (PAHs) in space. Remarkably, the observed abundance of cyanonaphthalene (CNN, C10H7CN) in the Taurus Molecular Cloud (TMC-1) is six orders of magnitude higher than expected from astrop...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2023-01-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-36092-0 |
| _version_ | 1826990777493880832 |
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| author | Mark H. Stockett James N. Bull Henrik Cederquist Suvasthika Indrajith MingChao Ji José E. Navarro Navarrete Henning T. Schmidt Henning Zettergren Boxing Zhu |
| author_facet | Mark H. Stockett James N. Bull Henrik Cederquist Suvasthika Indrajith MingChao Ji José E. Navarro Navarrete Henning T. Schmidt Henning Zettergren Boxing Zhu |
| author_sort | Mark H. Stockett |
| collection | DOAJ |
| description | Abstract After decades of searching, astronomers have recently identified specific Polycyclic Aromatic Hydrocarbons (PAHs) in space. Remarkably, the observed abundance of cyanonaphthalene (CNN, C10H7CN) in the Taurus Molecular Cloud (TMC-1) is six orders of magnitude higher than expected from astrophysical modeling. Here, we report unimolecular dissociation and radiative cooling rate coefficients of the 1-CNN isomer in its cationic form. These results are based on measurements of the time-dependent neutral product emission rate and kinetic energy release distributions produced from an ensemble of internally excited 1-CNN+ studied in an environment similar to that in interstellar clouds. We find that Recurrent Fluorescence – radiative relaxation via thermally populated electronic excited states – efficiently stabilizes 1-CNN+, owing to a large enhancement of the electronic transition probability by vibronic coupling. Our results help explain the anomalous abundance of CNN in TMC-1 and challenge the widely accepted picture of rapid destruction of small PAHs in space. |
| first_indexed | 2024-04-10T19:42:04Z |
| format | Article |
| id | doaj.art-76a69a384a9043afa1fbe1f6842b31f2 |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2025-02-18T08:26:29Z |
| publishDate | 2023-01-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-76a69a384a9043afa1fbe1f6842b31f22024-11-03T12:31:13ZengNature PortfolioNature Communications2041-17232023-01-011411810.1038/s41467-023-36092-0Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar cloudsMark H. Stockett0James N. Bull1Henrik Cederquist2Suvasthika Indrajith3MingChao Ji4José E. Navarro Navarrete5Henning T. Schmidt6Henning Zettergren7Boxing Zhu8Department of Physics, Stockholm UniversitySchool of Chemistry, University of East AngliaDepartment of Physics, Stockholm UniversityDepartment of Physics, Stockholm UniversityDepartment of Physics, Stockholm UniversityDepartment of Physics, Stockholm UniversityDepartment of Physics, Stockholm UniversityDepartment of Physics, Stockholm UniversityDepartment of Physics, Stockholm UniversityAbstract After decades of searching, astronomers have recently identified specific Polycyclic Aromatic Hydrocarbons (PAHs) in space. Remarkably, the observed abundance of cyanonaphthalene (CNN, C10H7CN) in the Taurus Molecular Cloud (TMC-1) is six orders of magnitude higher than expected from astrophysical modeling. Here, we report unimolecular dissociation and radiative cooling rate coefficients of the 1-CNN isomer in its cationic form. These results are based on measurements of the time-dependent neutral product emission rate and kinetic energy release distributions produced from an ensemble of internally excited 1-CNN+ studied in an environment similar to that in interstellar clouds. We find that Recurrent Fluorescence – radiative relaxation via thermally populated electronic excited states – efficiently stabilizes 1-CNN+, owing to a large enhancement of the electronic transition probability by vibronic coupling. Our results help explain the anomalous abundance of CNN in TMC-1 and challenge the widely accepted picture of rapid destruction of small PAHs in space.https://doi.org/10.1038/s41467-023-36092-0 |
| spellingShingle | Mark H. Stockett James N. Bull Henrik Cederquist Suvasthika Indrajith MingChao Ji José E. Navarro Navarrete Henning T. Schmidt Henning Zettergren Boxing Zhu Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds Nature Communications |
| title | Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds |
| title_full | Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds |
| title_fullStr | Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds |
| title_full_unstemmed | Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds |
| title_short | Efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds |
| title_sort | efficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small pahs in interstellar clouds |
| url | https://doi.org/10.1038/s41467-023-36092-0 |
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