Photoselective isotope fractionation dynamics of N 2 with cosmo and atmospheric chemistry perspectives
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Le résumé fourni par la source
Stable isotope ratio measurements provide valuable insights into a broad range of natural processes, from planetary atmospheres and climate to interstellar chemistry. Nitrogen, which has two stable isotopes, exhibits varying isotope ratios across the solar system. To model these observations, the isotope fraction as a function of energy is essential. At the Advanced Light Source (ALS), we measured the photodissociation of molecular nitrogen (N 2 ) with vacuum UV photons where a single photon is sufficiently energetic to dissociate the strong bond. The nitrogen atoms produced are scavenged with H 2 to form ammonia, whose isotopic makeup is determined. Blending the experiments with dynamical computations that include the shielding of light, we examine the isotopic composition and electronic atomic states produced. The measured photodissociation of N 2 at a natural isotopic composition with a frequency broad light beam exceptionally strongly favors the formation of the heavier nitrogen isotope, 15 N. Computations concur and suggest that the maximum in the quantum yield reflects significant variations in the specific electronic quantum states of the product N atoms that have quite different reactivities. Our quantum computations show that at similar energies, photodissociation of 14 N 14 N and 15 N 14 N can lead to different product channels. The computed dynamics include extensive state-selective spin–orbit and nonadiabatic couplings affecting the light absorption and dissociation pathways that proceed via the triplet manifold of states. Our results are relevant for future exploration missions, both in situ and sample-return and for other molecules such as O 2 and CO.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé, mais le titre doit être comparé manuellement.
- Titre Crossref
- Photoselective isotope fractionation dynamics of N <sub>2</sub> with cosmo and atmospheric chemistry perspectives
- Date Crossref
- 16/07/2025
- Éditeur
- National Academy of Sciences
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Hebrew University of Jerusalem Institute of Chemistry pays non établi dans la noticeUniversité ou école supérieure
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University of Liège Research Unit Molecular Systems B6c pays non établi dans la noticeUniversité ou école supérieure
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University of California Department of Chemistry and Biochemistry pays non établi dans la noticeUniversité ou école supérieure
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University of California System pays non établi dans la noticeUniversité ou école supérieure
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University of California San Diego pays non établi dans la noticeUniversité ou école supérieure
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Lawrence Berkeley National Laboratory Chemical Sciences Division pays non établi dans la noticeStructure de recherche
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David Geffen School of Medicine Department of Molecular and Medical Pharmacology pays non établi dans la noticeUniversité ou école supérieure
Institute of Chemistry — Hebrew University of Jerusalem, Research Unit Molecular Systems B6c — University of Liège et Department of Chemistry and Biochemistry — University of California, avec 4 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.