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Berné O, Martin-Drumel MA, Schroetter I, Goicoechea JR, Jacovella U, Gans B, Dartois E, Coudert LH, Bergin E, Alarcon F, Cami J, Roueff E, Black JH, Asvany O, Habart E, Peeters E, Canin A, Trahin B, Joblin C, Schlemmer S, Thorwirth S, Cernicharo J, Gerin M, Tielens A, Zannese M, Abergel A, Bernard-Salas J, Boersma C, Bron E, Chown R, Cuadrado S, Dicken D, Elyajouri M, Fuente A, Gordon KD, Issa L, Kannavou O, Khan B, Lacinbala O, Languignon D, Le Gal R, Maragkoudakis A, Meshaka R, Okada Y, Onaka T, Pasquini S, Pound MW, Robberto M, Röllig M, Schefter B, Schirmer T, Sidhu A, Tabone B, Van De Putte D, Vicente S, Wolfire MG. Formation of the methyl cation by photochemistry in a protoplanetary disk. Nature 2023; 621:56-59. [PMID: 37364766 DOI: 10.1038/s41586-023-06307-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/09/2023] [Indexed: 06/28/2023]
Abstract
Forty years ago, it was proposed that gas-phase organic chemistry in the interstellar medium can be initiated by the methyl cation CH3+ (refs. 1-3), but so far it has not been observed outside the Solar System4,5. Alternative routes involving processes on grain surfaces have been invoked6,7. Here we report James Webb Space Telescope observations of CH3+ in a protoplanetary disk in the Orion star-forming region. We find that gas-phase organic chemistry is activated by ultraviolet irradiation.
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Affiliation(s)
- Olivier Berné
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France.
| | | | - Ilane Schroetter
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
| | | | - Ugo Jacovella
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, Orsay, France
| | - Bérenger Gans
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, Orsay, France
| | - Emmanuel Dartois
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, Orsay, France
| | - Laurent H Coudert
- Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, Orsay, France
| | - Edwin Bergin
- Department of Astronomy, University of Michigan, Ann Arbor, MI, USA
| | - Felipe Alarcon
- Department of Astronomy, University of Michigan, Ann Arbor, MI, USA
| | - Jan Cami
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
- Institute for Earth and Space Exploration, The University of Western Ontario, London, Ontario, Canada
- Carl Sagan Center, SETI Institute, Mountain View, CA, USA
| | - Evelyne Roueff
- LERMA, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, Meudon, France
| | - John H Black
- Department of Space, Earth, and Environment, Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden
| | - Oskar Asvany
- I. Physikalisches Institut, Universität zu Köln, Cologne, Germany
| | - Emilie Habart
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Els Peeters
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
- Institute for Earth and Space Exploration, The University of Western Ontario, London, Ontario, Canada
- Carl Sagan Center, SETI Institute, Mountain View, CA, USA
| | - Amelie Canin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
| | - Boris Trahin
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Christine Joblin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
| | | | - Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Cologne, Germany
| | | | - Maryvonne Gerin
- LERMA, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, Meudon, France
| | - Alexander Tielens
- Leiden Observatory, Leiden University, Leiden, the Netherlands
- Astronomy Department, University of Maryland, College Park, MD, USA
| | - Marion Zannese
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Alain Abergel
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Jeronimo Bernard-Salas
- ACRI-ST, Centre dEtudes et de Recherche de Grasse (CERGA), Grasse, France
- INCLASS Common Laboratory, Grasse, France
| | | | - Emeric Bron
- LERMA, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, Meudon, France
| | - Ryan Chown
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
- Institute for Earth and Space Exploration, The University of Western Ontario, London, Ontario, Canada
| | - Sara Cuadrado
- Instituto de Física Fundamental (CSIC), Madrid, Spain
| | - Daniel Dicken
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Meriem Elyajouri
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | | | - Karl D Gordon
- Space Telescope Science Institute, Baltimore, MD, USA
| | - Lina Issa
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, UPS, Toulouse, France
| | - Olga Kannavou
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Baria Khan
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
| | - Ozan Lacinbala
- KU Leuven Quantum Solid State Physics (QSP), Leuven, Belgium
| | - David Languignon
- LERMA, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, Meudon, France
| | - Romane Le Gal
- Institut de Planétologie et d'Astrophysique de Grenoble, Université Grenoble Alpes, CNRS, Grenoble, France
- Institut de Radioastronomie Millimétrique (IRAM), Saint-Martin d'Hères, France
| | | | - Raphael Meshaka
- LERMA, Observatoire de Paris, PSL University, Sorbonne Université, CNRS, Meudon, France
| | - Yoko Okada
- I. Physikalisches Institut, Universität zu Köln, Cologne, Germany
| | - Takashi Onaka
- Department of Physics, Faculty of Science and Engineering, Meisei University, Tokyo, Japan
- Department of Astronomy, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Sofia Pasquini
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
| | - Marc W Pound
- Astronomy Department, University of Maryland, College Park, MD, USA
| | | | - Markus Röllig
- Physikalischer Verein-Gesellschaft für Bildung und Wissenschaft, Frankfurt, Germany
- Physikalisches Institut, Goethe-Universität, Frankfurt, Germany
| | - Bethany Schefter
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
| | - Thiébaut Schirmer
- Department of Space, Earth, and Environment, Chalmers University of Technology, Onsala Space Observatory, Onsala, Sweden
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | - Ameek Sidhu
- Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, Canada
- Institute for Earth and Space Exploration, The University of Western Ontario, London, Ontario, Canada
| | - Benoit Tabone
- Institut d'Astrophysique Spatiale, Université Paris-Saclay CNRS, Orsay, France
| | | | - Sílvia Vicente
- Instituto de Astrofísica e Ciências do Espaço, Lisbon, Portugal
| | - Mark G Wolfire
- Astronomy Department, University of Maryland, College Park, MD, USA
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Cernuto A, Lopes A, Romanzin C, Cunha de Miranda B, Ascenzi D, Tosi P, Tonachini G, Maranzana A, Polášek M, Žabka J, Alcaraz C. Effects of collision energy and vibrational excitation of CH 3+ cations on its reactivity with hydrocarbons: But-2-yne CH 3CCCH 3 as reagent partner. J Chem Phys 2017; 147:154302. [PMID: 29055295 DOI: 10.1063/1.4990514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The methyl carbocation is ubiquitous in gaseous environments, such as planetary ionospheres, cometary comae, and the interstellar medium, as well as combustion systems and plasma setups for technological applications. Here we report on a joint experimental and theoretical study on the mechanism of the reaction CH3+ + CH3CCCH3 (but-2-yne, also known as dimethylacetylene), by combining guided ion beam mass spectrometry experiments with ab initio calculations of the potential energy hypersurface. Such a reaction is relevant in understanding the chemical evolution of Saturn's largest satellite, Titan. Two complementary setups have been used: in one case, methyl cations are generated via electron ionization, while in the other case, direct vacuum ultraviolet photoionization with synchrotron radiation of methyl radicals is used to study internal energy effects on the reactivity. Absolute reactive cross sections have been measured as a function of collision energy, and product branching ratios have been derived. The two most abundant products result from electron and hydride transfer, occurring via direct and barrierless mechanisms, while other channels are initiated by the electrophilic addition of the methyl cation to the triple bond of but-2-yne. Among the minor channels, special relevance is placed on the formation of C5H7+, stemming from H2 loss from the addition complex. This is the only observed condensation product with the formation of new C-C bonds, and it might represent a viable pathway for the synthesis of complex organic species in astronomical environments and laboratory plasmas.
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Affiliation(s)
- Andrea Cernuto
- Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy
| | - Allan Lopes
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud 11 and Paris Saclay, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France
| | - Claire Romanzin
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud 11 and Paris Saclay, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France
| | | | - Daniela Ascenzi
- Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy
| | - Paolo Tosi
- Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy
| | - Glauco Tonachini
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, Torino I-10125, Italy
| | - Andrea Maranzana
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, Torino I-10125, Italy
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague 8, Czech Republic
| | - Jan Žabka
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague 8, Czech Republic
| | - Christian Alcaraz
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud 11 and Paris Saclay, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France
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8
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Cleeves LI, Bergin EA, Alexander CMO, Du F, Graninger D, Öberg KI, Harries TJ. EXPLORING THE ORIGINS OF DEUTERIUM ENRICHMENTS IN SOLAR NEBULAR ORGANICS. THE ASTROPHYSICAL JOURNAL 2016; 819:13. [PMID: 30842682 PMCID: PMC6398959 DOI: 10.3847/0004-637x/819/1/13] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues about their original formation environment. The organic materials in primitive solar system bodies generally have higher D/H ratios and show greater D/H variation when compared to D/H in solar system water. We propose this difference arises at least in part due to (1) the availability of additional chemical fractionation pathways for organics beyond that for water, and (2) the higher volatility of key carbon reservoirs compared to oxygen. We test this hypothesis using detailed disk models, including a sophisticated, new disk ionization treatment with a low cosmic-ray ionization rate, and find that disk chemistry leads to higher deuterium enrichment in organics compared to water, helped especially by fractionation via the precursorsCH 2 D + / CH 3 + . We also find that the D/H ratio in individual species varies significantly depending on their particular formation pathways. For example, from ~20-40 au, CH4 can reach D/H ~ 2 × 10-3, while D/H in CH3OH remains locally unaltered. Finally, while the global organic D/H in our models can reproduce intermediately elevated D/H in the bulk hydrocarbon reservoir, our models are unable to reproduce the most deuterium-enriched organic materials in the solar system, and thus our model requires some inheritance from the cold interstellar medium from which the Sun formed.
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Affiliation(s)
- L Ilsedore Cleeves
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA;
| | - Edwin A Bergin
- Department of Astronomy, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109, USA
| | | | - Fujun Du
- Department of Astronomy, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109, USA
| | - Dawn Graninger
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA;
| | - Karin I Öberg
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA;
| | - Tim J Harries
- Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
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