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Chahbazian R, Martin-Drumel MA, Pirali O. High-Resolution Spectroscopic Investigation of the CH 2CHO Radical in the Sub-Millimeter Region. J Phys Chem A 2024; 128:370-377. [PMID: 38179716 DOI: 10.1021/acs.jpca.3c06326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
In this work, the pure rotational spectrum of the vinoxy radical (CH2CHO) has been studied at millimeter and sub-millimeter wavelengths (110-860 GHz). CH2CHO was produced by H-abstraction from acetaldehyde (CH3CHO) using atomic fluorine in a double-pass absorption cell at room temperature. A Zeeman-modulation spectrometer, in which an external magnetic field generated inside the absorption cell is amplitude-modulated, was used to record the pure rotational transitions of the radical. The recorded spectra are devoid of signals from closed-shell species, allowing for relatively fast acquisitions over wide spectral windows. Transitions involving values of the rotational quantum numbers N″ and Ka″ up to 41 and 18, respectively, were measured and combined with all available high-resolution literature data (both pure rotation and ground-state combination differences from ro-vibration) to greatly improve the modeling of the CH2CHO spectrum. The combined experimental line list is fit using a semirigid rotor Hamiltonian, and the results are compared to quantum chemical calculations. This laboratory study provides the spectroscopic information needed to search for CH2CHO in various interstellar environments, from cold (e.g., typically 10 K for dense molecular clouds) to warm (e.g., ∼200 K for hot corinos) objects.
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Affiliation(s)
- Rosemonde Chahbazian
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91400 Orsay, France
| | | | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91400 Orsay, France
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2
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Djevahirdjian L, Lechevallier L, Martin-Drumel MA, Pirali O, Ducournau G, Kassi R, Kassi S. Frequency stable and low phase noise THz synthesis for precision spectroscopy. Nat Commun 2023; 14:7162. [PMID: 37935704 PMCID: PMC10630442 DOI: 10.1038/s41467-023-42905-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 10/24/2023] [Indexed: 11/09/2023] Open
Abstract
We present a robust approach to generate a continuously tunable, low phase noise, Hz linewidth and mHz/s stability THz emission in the 0.1 THz to 1.4 THz range. This is achieved by photomixing two commercial telecom, distributed feedback lasers locked by optical-feedback onto a single highly stable V-shaped optical cavity. The phase noise is evaluated up to 1.2 THz, demonstrating Hz-level linewidth. To illustrate the spectral performances and agility of the source, low pressure absorption lines of methanol and water vapors have been recorded up to 1.4 THz. In addition, the hyperfine structure of a water line at 556.9 GHz, obtained by saturation spectroscopy, is also reported, resolving spectral features displaying a full-width at half-maximum of 10 kHz. The present results unambiguously establish the performances of this source for ultra-high resolution molecular physics.
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Affiliation(s)
| | | | | | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France.
| | - Guillaume Ducournau
- Université de Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 IEMN, Institut d'Electronique de Microélectronique et de Nanotechnologie, 59655 Villeneuve d'Ascq, France.
| | - Rédha Kassi
- Université de Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, UMR 8520 IEMN, Institut d'Electronique de Microélectronique et de Nanotechnologie, 59655 Villeneuve d'Ascq, France.
| | - Samir Kassi
- Univ. Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
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3
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Martin-Drumel MA, Spaniol JT, Hölzel H, Agúndez M, Cernicharo J, Moth-Poulsen K, Jacovella U. Searches for bridged bicyclic molecules in space-norbornadiene and its cyano derivatives. Faraday Discuss 2023; 245:284-297. [PMID: 37305958 PMCID: PMC10510035 DOI: 10.1039/d3fd00016h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/14/2023] [Indexed: 09/21/2023]
Abstract
The norbornadiene (NBD) molecule, C7H8, owes its fame to its remarkable photoswitching properties that are promising for molecular solar-thermal energy storage systems. Besides this photochemical interest, NBD is a rather unreactive species within astrophysical conditions and it should exhibit high photostability, properties that might also position this molecule as an important constituent of the interstellar medium (ISM)-especially in environments that are well shielded from short-wavelength radiation, such as dense molecular clouds. It is thus conceivable that, once formed, NBD can survive in dense molecular clouds and act as a carbon sink. Following the recent interstellar detections of large hydrocarbons, including several cyano-containing ones, in the dense molecular cloud TMC-1, it is thus logical to consider searching for NBD-which presents a shallow but non-zero permanent electric dipole moment (0.06 D)-as well as for its mono- and dicyano-substituted compounds, referred to as CN-NBD and DCN-NBD, respectively. The pure rotational spectra of NBD, CN-NBD, and DCN-NBD have been measured at 300 K in the 75-110 GHz range using a chirped-pulse Fourier-transform millimetre-wave spectrometer. Of the three species, only NBD was previously studied at high resolution in the microwave domain. From the present measurements, the derived spectroscopic constants enable prediction of the spectra of all three species at various rotational temperatures (up to 300 K) in the spectral range mapped at high resolution by current radio observatories. Unsuccessful searches for these molecules were conducted toward TMC-1 using the QUIJOTE survey, carried out at the Yebes telescope, allowing derivation of the upper limits to the column densities of 1.6 × 1014 cm-2, 4.9 × 1010 cm-2, and 2.9 × 1010 cm-2 for NBD, CN-NBD, and DCN-NBD, respectively. Using CN-NBD and cyano-indene as proxies for the corresponding bare hydrocarbons, this indicates that-if present in TMC-1-NBD would be at least four times less abundant than indene.
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Affiliation(s)
| | - Jean-Thibaut Spaniol
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.
| | - Helen Hölzel
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Marcelino Agúndez
- Instituto de Física Fundamental, CSIC, Department of Molecular Astrophysics, Serrano 121, E-28006 Madrid, Spain
| | - Jose Cernicharo
- Instituto de Física Fundamental, CSIC, Department of Molecular Astrophysics, Serrano 121, E-28006 Madrid, Spain
| | - Kasper Moth-Poulsen
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden
- The Institute of Materials Science of Barcelona, ICMAB-CSIC, Bellaterra, 08193 Barcelona, Spain
- Catalan Institution for Research & Advanced Studies, ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
- Department of Chemical Engineering, Universitat Politècnica de Catalunya, EEBE, Eduard Maristany 10-14, 08019 Barcelona, Spain
| | - Ugo Jacovella
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.
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4
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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5
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Spaniol JT, Lee KLK, Pirali O, Puzzarini C, Martin-Drumel MA. A rotational investigation of the three isomeric forms of cyanoethynylbenzene (HCC-C 6H 4-CN): benchmarking experiments and calculations using the "Lego brick" approach. Phys Chem Chem Phys 2023; 25:6397-6405. [PMID: 36779600 DOI: 10.1039/d2cp04825f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We report the study of three structural isomers of phenylpropiolonitrile (3-phenyl-2-propynenitrile, C6H5-C3N) containing an alkyne function and a cyano group, namely ortho-, meta-, and para-cyanoethynylbenzene (HCC-C6H4-CN). The pure rotational spectra of these species have been recorded at room temperature in the millimeter-wave domain using a chirped-pulse spectrometer (75-110 GHz) and a source-frequency modulation spectrometer (140-220 GHz). Assignments of transitions in the vibrational ground state and several vibrationally excited states were supported by quantum chemical calculations using the so-called "Lego brick" approach [A. Melli, F. Tonolo, V. Barone and C. Puzzarini, J. Phys. Chem. A, 2021, 125, 9904-9916]. From these assignments, accurate spectroscopic (rotational and centrifugal distortion) constants have been derived: for all species and all observed vibrational states, predicted rotational constants show relative accuracy better than 0.1%, and often of the order of 0.01%, compared to the experimental values. The present work hence further validates the use of the "Lego brick" approach for predicting spectroscopic constants with high precision.
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Affiliation(s)
- Jean-Thibaut Spaniol
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.
| | - Kin Long Kelvin Lee
- Intel Accelerated Computing Systems and Graphics Group, Intel JF5 2111 NE 25th Ave, Hillsboro, OR 97124, USA
| | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, via F. Selmi 2, 40126 Bologna, Italy.
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6
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Jiang N, Melosso M, Alessandrini S, Bizzocchi L, Martin-Drumel MA, Pirali O, Puzzarini C. Insights into the molecular structure and infrared spectrum of the prebiotic species aminoacetonitrile. Phys Chem Chem Phys 2023; 25:4754-4763. [PMID: 36691972 DOI: 10.1039/d2cp05179f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Aminoacetonitrile is an interstellar molecule with a prominent prebiotic role, already detected in the chemically-rich molecular cloud Sagittarius B2(N) and postulated to be present in the atmosphere of the largest Saturn's moon, Titan. To further support its observation in such remote environments and laboratory experiments aimed at improving our understanding of interstellar chemistry, we report a thorough spectroscopic and structural characterization of aminoacetonitrile. Equilibrium geometry, fundamental bands as well as spectroscopic and molecular parameters have been accurately computed by exploiting a composite scheme rooted in the coupled-cluster theory that accounts for the extrapolation to the complete basis set limit and core-correlation effects. In addition, a semi-experimental approach that combines ground-state rotational constants for different isotopic species and calculated vibrational corrections has been employed for the structure determination. From the experimental side, we report the analysis of the three strongest fundamental bands of aminoacetonitrile observed between 500 and 1000 cm-1 in high-resolution infrared spectra. More generally, all computed band positions are in excellent agreement with the present and previous experiments. The only exception is the ν15 band, for which we provide a revision of the experimental assignment, now in good agreement with theory.
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Affiliation(s)
- Ningjing Jiang
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy.
| | - Mattia Melosso
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Naples, Italy.
| | - Silvia Alessandrini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy. .,Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Luca Bizzocchi
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy.
| | | | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France.,SOLEIL Synchrotron, AILES beamline, l'Orme des Merisiers, 91190 Saint-Aubin, Gif-sur-Yvette, France
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy.
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7
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Chitarra O, Pirali O, Spaniol JT, Hearne TS, Loison JC, Stanton JF, Martin-Drumel MA. Pure Rotational Spectroscopy of the CH 2CN Radical Extended to the Sub-Millimeter Wave Spectral Region. J Phys Chem A 2022; 126:7502-7513. [PMID: 36198131 DOI: 10.1021/acs.jpca.2c04399] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a thorough pure rotational investigation of the CH2CN radical in its ground vibrational state. Our measurements cover the millimeter and sub-millimeter wave spectral regions (79-860 GHz) using a W-band chirped-pulse instrument and a frequency multiplication chain-based spectrometer. The radical was produced in a flow cell at room temperature by H abstraction from acetonitrile using atomic fluorine. The newly recorded transitions of CH2CN (involving N″ and Ka″ up to 42 and 8, respectively) were combined with the literature data, leading to a refinement of the spectroscopic parameters of the species using a Watson S-reduced Hamiltonian. In particular, the A rotational constant and K-dependent parameters are significantly better determined than in previous studies. The present model, which reproduces all experimental transitions to their experimental accuracy, allows for confident searches for the radical in cold to warm environments of the interstellar medium.
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Affiliation(s)
- Olivia Chitarra
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405Orsay, France
| | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405Orsay, France
| | - Jean-Thibaut Spaniol
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405Orsay, France
| | - Thomas S Hearne
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405Orsay, France
| | | | - John F Stanton
- Quantum Theory Project, Department of Chemistry, University of Florida, Gainesville32611, Florida, United States
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8
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Genossar N, Changala PB, Gans B, Loison JC, Hartweg S, Martin-Drumel MA, Garcia GA, Stanton JF, Ruscic B, Baraban JH. Ring-Opening Dynamics of the Cyclopropyl Radical and Cation: the Transition State Nature of the Cyclopropyl Cation. J Am Chem Soc 2022; 144:18518-18525. [PMID: 36174230 DOI: 10.1021/jacs.2c07740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We provide compelling experimental and theoretical evidence for the transition state nature of the cyclopropyl cation. Synchrotron photoionization spectroscopy employing coincidence techniques together with a novel simulation based on high-accuracy ab initio calculations reveal that the cation is unstable via its allowed disrotatory ring-opening path. The ring strains of the cation and the radical are similar, but both ring opening paths for the radical are forbidden when the full electronic symmetries are considered. These findings are discussed in light of the early predictions by Longuet-Higgins alongside Woodward and Hoffman; we also propose a simple phase space explanation for the appearance of the cyclopropyl photoionization spectrum. The results of this work allow the refinement of the cyclopropane C-H bond dissociation energy, in addition to the cyclopropyl radical and cation cyclization energies, via the Active Thermochemical Tables approach.
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Affiliation(s)
- Nadav Genossar
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,Israel Atomic Energy Commission, P.O. Box 7061, Tel Aviv 61070, Israel
| | - P Bryan Changala
- Center for Astrophysics─Harvard & Smithsonian, Cambridge, Massachusetts 02138, United States
| | - Bérenger Gans
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay 91405, France
| | | | - Sebastian Hartweg
- Synchrotron Soleil, L'Orme des Merisiers, St. Aubin BP48, Gif sur Yvette F-91192, France
| | | | - Gustavo A Garcia
- Synchrotron Soleil, L'Orme des Merisiers, St. Aubin BP48, Gif sur Yvette F-91192, France
| | - John F Stanton
- Quantum Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, Florida 32611, United States
| | - Branko Ruscic
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Joshua H Baraban
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
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9
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Bruckhuisen J, Dhont G, Roucou A, Jabri A, Bayoudh H, Tran TT, Goubet M, Martin-Drumel MA, Cuisset A. Intramolecular H-Bond Dynamics of Catechol Investigated by THz High-Resolution Spectroscopy of Its Low-Frequency Modes. Molecules 2021; 26:molecules26123645. [PMID: 34203730 PMCID: PMC8232127 DOI: 10.3390/molecules26123645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/07/2021] [Accepted: 06/10/2021] [Indexed: 11/16/2022] Open
Abstract
Catechol is an oxygenated aromatic volatile organic compound and a biogenic precursor of secondary organic aerosols. Monitoring this compound in the gas phase is desirable due to its appreciable reactivity with tropospheric ozone. From a molecular point of view, this molecule is attractive since the two adjacent hydroxy groups can interchangeably act as donor and acceptor in an intramolecular hydrogen bonding due to the tunnelling between two symmetrically equivalent structures. Using synchrotron radiation, we recorded a rotationally-resolved Fourier Transform far-infrared (IR) spectrum of the torsional modes of the free and bonded -OH groups forming the intramolecular hydrogen bond. Additionally, the room temperature, pure rotational spectrum was measured in the 70–220 GHz frequency range using a millimeter-wave spectrometer. The assignment of these molecular transitions was assisted by anharmonic high-level quantum-chemical calculations. In particular, pure rotational lines belonging to the ground and the four lowest energy, vibrationally excited states were assigned. Splitting due to the tunnelling was resolved for the free -OH torsional state. A global fit combining the far-IR and millimeter-wave data provided the spectroscopic parameters of the low-energy far-IR modes, in particular those characterizing the intramolecular hydrogen bond dynamics.
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Affiliation(s)
- Jonas Bruckhuisen
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
| | - Guillaume Dhont
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
| | - Anthony Roucou
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
| | - Atef Jabri
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
| | - Hamdi Bayoudh
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
| | - Thi Thanh Tran
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
| | - Manuel Goubet
- UMR8523—PhLAM—Physique des Lasers Atomes et Molécules, Université de Lille, CNRS, F-59000 Lille, France;
| | | | - Arnaud Cuisset
- UR4493, LPCA, Laboratoire de Physico-Chimie de l’Atmosphère, Université du Littoral Côte d’Opale, F-59140 Dunkerque, France; (J.B.); (G.D.); (A.R.); (A.J.); (H.B.); (T.T.T.)
- Correspondence:
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10
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Goubet M, Martin-Drumel MA, Réal F, Vallet V, Pirali O. Conformational Landscape of Oxygen-Containing Naphthalene Derivatives. J Phys Chem A 2020; 124:4484-4495. [DOI: 10.1021/acs.jpca.0c01188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Manuel Goubet
- Université Lille, CNRS, UMR 8523-PhLAM-Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | | | - Florent Réal
- Université Lille, CNRS, UMR 8523-PhLAM-Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | - Valérie Vallet
- Université Lille, CNRS, UMR 8523-PhLAM-Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
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11
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Martin-Drumel MA, Porterfield JP, Goubet M, Asselin P, Georges R, Soulard P, Nava M, Changala PB, Billinghurst B, Pirali O, McCarthy MC, Baraban JH. Synchrotron-Based High Resolution Far-Infrared Spectroscopy of trans-Butadiene. J Phys Chem A 2020; 124:2427-2435. [DOI: 10.1021/acs.jpca.0c00623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Jessica P. Porterfield
- Center for Astrophysics, Harvard & Smithsonian, Cambridge, Massachusetts 02138, United States
| | - Manuel Goubet
- Université Lille, CNRS, UMR 8523-PhLAM-Physique des Lasers, Atomes et Molécules, F-59000 Lille, France
| | - Pierre Asselin
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, F-75005 Paris, France & CNRS, UMR 8233, MONARIS, F-75005 Paris, France
| | - Robert Georges
- Institut de Physique de Rennes, CNRS, UMR 6251, Université de Rennes 1, F-35042 Rennes, France
| | - Pascale Soulard
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8233, MONARIS, F-75005 Paris, France & CNRS, UMR 8233, MONARIS, F-75005 Paris, France
| | - Matthew Nava
- Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138, United States
| | - P. Bryan Changala
- JILA, University of Colorado, Boulder, Colorado 80309, United States
| | - Brant Billinghurst
- Canadian Light Source, University of Saskatchewan, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Olivier Pirali
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d’Orsay, 91405 Orsay, France
| | - Michael C. McCarthy
- Center for Astrophysics, Harvard & Smithsonian, Cambridge, Massachusetts 02138, United States
| | - Joshua H. Baraban
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
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12
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Lee KLK, Thorwirth S, Martin-Drumel MA, McCarthy MC. Generation and structural characterization of Ge carbides GeC n (n = 4, 5, 6) by laser ablation, broadband rotational spectroscopy, and quantum chemistry. Phys Chem Chem Phys 2019; 21:18911-18919. [PMID: 31451831 DOI: 10.1039/c9cp03607e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Following the recent discovery of T-shaped GeC2, rotational spectra of three larger Ge carbides, linear GeC4, GeC5, and GeC6 have been observed using chirped pulse and cavity Fourier transform microwave spectroscopy and a laser ablation molecule source, guided by new high-level quantum chemical calculations of their molecular structure. Like their isovalent Si-bearing counterparts, Ge carbides with an even number of carbon atoms beyond GeC2 are predicted to possess 1Σ ground electronic states, while odd-numbered carbon chains are generally 3Σ; all are predicted to be highly polar. For the three new molecules detected in this work, rotational lines of four of the five naturally occurring Ge isotopic variants have been observed between 6 and 22 GHz. Combining these measurements with ab initio force fields, the Ge-C bond lengths have been determined to high precision: the derived values of 1.776 Å for GeC4, 1.818 Å for GeC5, and 1.782 Å for GeC6 indicate a double bond between these two atoms. Somewhat surprisingly, the spectrum of GeC5 very closely resembles that of a 1Σ molecule, implying a spin-spin coupling constant λ in excess of 770 GHz for this radical, a likely consequence of the large spin-orbit constant of atomic Ge (∼1000 cm-1). A systematic comparison between the production of SiCn and GeCn chains by laser ablation has also been undertaken. The present work suggests that other large metal-bearing molecules may be amenable to detection by similar means.
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Affiliation(s)
- Kin Long Kelvin Lee
- Center for Astrophysics, Harvard-Smithsonian, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
| | - Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany
| | - Marie-Aline Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Michael C McCarthy
- Center for Astrophysics, Harvard-Smithsonian, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
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13
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Johansen SL, Martin-Drumel MA, Crabtree KN. Rotational Spectrum of the β-Cyanovinyl Radical: A Possible Astrophysical N-Heterocycle Precursor. J Phys Chem A 2019; 123:5171-5177. [PMID: 31135161 DOI: 10.1021/acs.jpca.9b03798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A fundamental question in the field of astrochemistry is whether the molecules essential to life originated in the interstellar medium (ISM), and, if so, how they were formed. Nitrogen-containing heterocycles are of particular interest because of their role in biology; however, to date, no N-heterocycle has been detected in the ISM, and it is unclear how and where such species might form. Recently, the β-cyanovinyl radical (HCCHCN) was implicated in the low-temperature gas-phase formation of pyridine. While neutral vinyl cyanide (H2CCHCN) has been rotationally characterized and detected in the ISM, HCCHCN has not. Here, we present the first theoretical study of all three cyanovinyl isomers at the CCSD(T)/ANO1 level of theory and the experimental rotational spectra of cis- and trans-HCCHCN, as well as those of their 15N isotopologues, from 5 to 75 GHz. The observed spectra are in good agreement with calculations and provide a basis for further laboratory and astronomical investigations of these radicals.
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Affiliation(s)
- Sommer L Johansen
- Department of Chemistry , University of California , Davis, One Shields Ave., Davis , California 95616 , United States
| | - Marie-Aline Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay , CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay , France
| | - Kyle N Crabtree
- Department of Chemistry , University of California , Davis, One Shields Ave., Davis , California 95616 , United States
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14
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Martin-Drumel MA, Baraban JH, Changala PB, Stanton JF, McCarthy MC. The Hunt for Elusive Molecules: Insights from Joint Theoretical and Experimental Investigations. Chemistry 2019; 25:7243-7258. [PMID: 30673130 DOI: 10.1002/chem.201805986] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 11/10/2022]
Abstract
Rotational spectroscopy is an invaluable tool to unambiguously determine the molecular structure of a species, and sometimes even to establish its very existence. This article illustrates how experimental and theoretical state-of-the-art tools can be used in tandem to investigate the rotational structure of molecules, with particular emphasis on those that have long remained elusive. The examples of three emblematic species-gauche-butadiene, disilicon carbide, and germanium dicarbide-highlight the close, mutually beneficial interaction between high-level theoretical calculations and sensitive microwave measurements. Prospects to detect other elusive molecules of chemical and astronomical interest are discussed.
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Affiliation(s)
- Marie-Aline Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405, Orsay, France
| | - Joshua H Baraban
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - P Bryan Changala
- JILA, National Institute of Standards and Technology and Department of, Physics, University of Colorado, Boulder, CO, 80309, USA
| | - John F Stanton
- Quantum Theory Project, Departments of Chemistry and Physics, Univ. of Florida, Gainesville, FL, 32611, USA
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, 02138, USA
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15
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Affiliation(s)
| | - Marie-Aline Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay, CNRS, Univ Paris Sud, Université Paris-Saclay, Orsay, France
| | - Valerio Lattanzi
- The Center for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik, Garching, Germany
| | - Brett A. McGuire
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
- NAASC, National Radio Astronomy Observatory, Charlottesville, VA, USA
| | - Paola Caselli
- The Center for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik, Garching, Germany
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16
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Roucou A, Dhont G, Cuisset A, Martin-Drumel MA, Thorwirth S, Fontanari D, Meerts WL. High resolution study of the ν 2 and ν 5 rovibrational fundamental bands of thionyl chloride: Interplay of an evolutionary algorithm and a line-by-line analysis. J Chem Phys 2018; 147:054303. [PMID: 28789547 DOI: 10.1063/1.4996655] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The ν2 and ν5 fundamental bands of thionyl chloride (SOCl2) were measured in the 420 cm-1-550 cm-1 region using the FT-far-IR spectrometer exploiting synchrotron radiation on the AILES beamline at SOLEIL. A straightforward line-by-line analysis is complicated by the high congestion of the spectrum due to both the high density of SOCl2 rovibrational bands and the presence of the ν2 fundamental band of sulfur dioxide produced by hydrolysis of SOCl2 with residual water. To overcome this difficulty, our assignment procedure for the main isotopologues 32S16O35Cl2 and 32S16O35Cl37Cl alternates between a direct fit of the spectrum, via a global optimization technique, and a traditional line-by-line analysis. The global optimization, based on an evolutionary algorithm, produces rotational constants and band centers that serve as useful starting values for the subsequent spectroscopic analysis. This work helped to identify the pure rotational submillimeter spectrum of 32S16O35Cl2 in the v2=1 and v5=1 vibrational states of Martin-Drumel et al. [J. Chem. Phys. 144, 084305 (2016)]. As a by-product, the rotational transitions of the v4=1 far-IR inactive state were identified in the submillimeter spectrum. A global fit gathering all the microwave, submillimeter, and far-IR data of thionyl chloride has been performed, showing that no major perturbation of rovibrational energy levels occurs for the main isotopologue of the molecule.
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Affiliation(s)
- Anthony Roucou
- Laboratoire de Physico-Chimie de l'Atmosphère, CNRS EA-4493, Université du Littoral Côte d'Opale, 59140 Dunkerque, France
| | - Guillaume Dhont
- Laboratoire de Physico-Chimie de l'Atmosphère, CNRS EA-4493, Université du Littoral Côte d'Opale, 59140 Dunkerque, France
| | - Arnaud Cuisset
- Laboratoire de Physico-Chimie de l'Atmosphère, CNRS EA-4493, Université du Littoral Côte d'Opale, 59140 Dunkerque, France
| | - Marie-Aline Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay, CNRS, Bâtiment 210, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Köln, Germany
| | - Daniele Fontanari
- Laboratoire de Physico-Chimie de l'Atmosphère, CNRS EA-4493, Université du Littoral Côte d'Opale, 59140 Dunkerque, France
| | - W Leo Meerts
- Institute for Molecules and Materials, Molecular and Biophysics Group, Felix Laboratory, Radboud University, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
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17
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Abstract
A systematic search for carbon-chain cumulenones beyond H2C4O has been undertaken using microwave spectral taxonomy in combination with a pulsed jet discharge source. No evidence was found for the C2υ isomer of H2C5O or its longer derivatives, but HC(O)C4H, the longer variant of propynal, HC(O)CCH, was identified instead. Its rotational and leading centrifugal distortion constants have been derived to high accuracy from detection of both a- and b-type lines; those below 40 GHz were measured using a Fabry-Perot cavity, while lines between 40 and 72 GHz were recorded by double resonance techniques. Overwhelming evidence for the identification is provided by detection of HC(O)C4D, DC(O)C4H, and HC(18O)C4H at the expected frequencies using isotopically enriched samples. Because HC(18O)C4H is produced with comparable abundance when using either 18O2 or C18O as the source of oxygen, and because H13C(O)C4H is not preferentially formed when starting from 13CO, atomic oxygen appears to be a key reactant in formation, plausibly via O insertion, e.g., H2CC2n+2H + O → HC(O)C2n+2H + H. Under the same experimental conditions, HC(O)CCH is more than 10 times more abundant than H2C3O, regardless of the source of oxygen, and no evidence is found for cyclopropenone, c-C3H2O. Taken together, these observations indicate that propynal and longer chains with an odd number of carbon atoms are either energetically more stable than cumulenones of the same size, are kinetically favored products, or both. On the basis of the HC(O)C4H discovery, searches for the isovalent sulfur species, HC(S)C4H, and HC(O)C6H have been conducted. Guided by new quantum chemical calculations, the rotational spectra of both were observed in the centimeter-wave band with the same spectrometer.
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Affiliation(s)
- Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Luyao Zou
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Marie-Aline Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
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18
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McGuire BA, Martin-Drumel MA, Thorwirth S, Brünken S, Lattanzi V, Neill JL, Spezzano S, Yu Z, Zaleski DP, Remijan AJ, Pate BH, McCarthy MC. Molecular polymorphism: microwave spectra, equilibrium structures, and an astronomical investigation of the HNCS isomeric family. Phys Chem Chem Phys 2018; 18:22693-705. [PMID: 27478937 DOI: 10.1039/c6cp03871a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The rotational spectra of thioisocyanic acid (HNCS), and its three energetic isomers (HSCN, HCNS, and HSNC) have been observed at high spectral resolution by a combination of chirped-pulse and Fabry-Pérot Fourier-transform microwave spectroscopy between 6 and 40 GHz in a pulsed-jet discharge expansion. Two isomers, thiofulminic acid (HCNS) and isothiofulminic acid (HSNC), calculated here to be 35-37 kcal mol(-1) less stable than the ground state isomer HNCS, have been detected for the first time. Precise rotational, centrifugal distortion, and nitrogen hyperfine coupling constants have been determined for the normal and rare isotopic species of both molecules; all are in good agreement with theoretical predictions obtained at the coupled cluster level of theory. On the basis of isotopic spectroscopy, precise molecular structures have been derived for all four isomers by correcting experimental rotational constants for the effects of rotation-vibration interaction calculated theoretically. Formation and isomerization pathways have also been investigated; the high abundance of HSCN relative to ground state HNCS, and the detection of strong lines of SH using CH3CN and H2S, suggest that HSCN is preferentially produced by the radical-radical reaction HS + CN. A radio astronomical search for HSCN and its isomers has been undertaken toward the high-mass star-forming region Sgr B2(N) in the Galactic Center with the 100 m Green Bank Telescope. While we find clear evidence for HSCN, only a tentative detection of HNCS is proposed, and there is no indication of HCNS or HSNC at the same rms noise level. HSCN, and tentatively HNCS, displays clear deviations from a single-excitation temperature model, suggesting weak masing may be occurring in some transitions in this source.
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Affiliation(s)
- Brett A McGuire
- National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903, USA and Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | | | - Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - Sandra Brünken
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - Valerio Lattanzi
- Max-Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
| | - Justin L Neill
- Department of Chemistry, University of Virginia, McCormick Rd., Charlottesville, VA 22904, USA
| | - Silvia Spezzano
- Max-Planck Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
| | | | - Daniel P Zaleski
- Department of Chemistry, University of Virginia, McCormick Rd., Charlottesville, VA 22904, USA
| | - Anthony J Remijan
- National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903, USA
| | - Brooks H Pate
- Department of Chemistry, University of Virginia, McCormick Rd., Charlottesville, VA 22904, USA
| | - Michael C McCarthy
- National Radio Astronomy Observatory, 520 Edgemont Rd, Charlottesville, VA 22903, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, USA.
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McGuire BA, Martin-Drumel MA, Lee KLK, Stanton JF, Gottlieb CA, McCarthy MC. Vibrational satellites of C2S, C3S, and C4S: microwave spectral taxonomy as a stepping stone to the millimeter-wave band. Phys Chem Chem Phys 2018; 20:13870-13889. [DOI: 10.1039/c8cp01102h] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a microwave spectral taxonomy study of several hydrocarbon/CS2 discharge mixtures, in which more than 60 distinct species/vibrational states were detected and analyzed.
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Affiliation(s)
- Brett A. McGuire
- National Radio Astronomy Observatory
- Charlottesville
- USA
- Harvard-Smithsonian Center for Astrophysics
- Cambridge
| | | | | | | | | | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics
- Cambridge
- USA
- School of Engineering and Applied Sciences
- Harvard University
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20
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Abstract
Supercritical CO2 is an appealing nontoxic, environmentally friendly solvent for the industrial extraction of many classes of compounds, from caffeine to natural product drug precursors to petrochemical impurities. Apolar in isolation, the ability of supercritical CO2 to dissolve polar species has been empirically shown to be greatly enhanced by the addition of a small molar percentage of a polar cosolvent, often ethanol. Computational work predicts that the isolated ethanol-CO2 complex can exist either in an electron-donor configuration or through a hydrogen-bonding one; yet, neither has been previously experimentally observed. Here, we demonstrate by rotational spectroscopy that the isolated, gas-phase ethanol-CO2 dimer is an electron donor-acceptor complex.
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Affiliation(s)
- Brett A McGuire
- National Radio Astronomy Observatory , Charlottesville, Virginia 22903, United States.,Harvard-Smithsonian Center for Astrophysics and School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Marie-Aline Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics and School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics and School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
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21
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Zingsheim O, Martin-Drumel MA, Thorwirth S, Schlemmer S, Gottlieb CA, Gauss J, McCarthy MC. Germanium Dicarbide: Evidence for a T-Shaped Ground State Structure. J Phys Chem Lett 2017; 8:3776-3781. [PMID: 28742354 DOI: 10.1021/acs.jpclett.7b01544] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The equilibrium structure of germanium dicarbide GeC2 has been an open question since the late 1950s. Although most high-level quantum calculations predict an L-shaped geometry, a T-shaped or even a linear geometry cannot be ruled out because of the very flat potential energy surface. By recording the rotational spectrum of this dicarbide using sensitive microwave and millimeter techniques, we unambiguously establish that GeC2 adopts a vibrationally averaged T-shaped structure in its ground state. From analysis of 14 isotopologues, a precise r0 structure has been derived, yielding a Ge-C bond length of 1.952(1) Å and an apex angle of 38.7(2)°.
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Affiliation(s)
- Oliver Zingsheim
- I. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Marie-Aline Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts 02138, United States
- School of Engineering & Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Sven Thorwirth
- I. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln , Zülpicher Straße 77, 50937 Köln, Germany
| | - Carl A Gottlieb
- Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts 02138, United States
- School of Engineering & Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Jürgen Gauss
- Institut für Physikalische Chemie, Universität Mainz , 55099 Mainz, Germany
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics , Cambridge, Massachusetts 02138, United States
- School of Engineering & Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States
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22
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Nava M, Martin-Drumel MA, Lopez CA, Crabtree KN, Womack CC, Nguyen TL, Thorwirth S, Cummins CC, Stanton JF, McCarthy MC. Spontaneous and Selective Formation of HSNO, a Crucial Intermediate Linking H2S and Nitroso Chemistries. J Am Chem Soc 2016; 138:11441-4. [DOI: 10.1021/jacs.6b05886] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Matthew Nava
- Department
of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Marie-Aline Martin-Drumel
- Harvard-Smithsonian
Center for Astrophysics and School of Engineering
and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Christopher A. Lopez
- Institute
for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Kyle N. Crabtree
- Harvard-Smithsonian
Center for Astrophysics and School of Engineering
and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Caroline C. Womack
- Department
of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Thanh L. Nguyen
- Institute
for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Sven Thorwirth
- I. Physikalisches
Institut, Universität zu Köln, 50937 Köln, Germany
| | - Christopher C. Cummins
- Department
of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - John F. Stanton
- Institute
for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Michael C. McCarthy
- Harvard-Smithsonian
Center for Astrophysics and School of Engineering
and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
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23
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Crabtree KN, Martin-Drumel MA, Brown GG, Gaster SA, Hall TM, McCarthy MC. Microwave spectral taxonomy: A semi-automated combination of chirped-pulse and cavity Fourier-transform microwave spectroscopy. J Chem Phys 2016; 144:124201. [PMID: 27036440 DOI: 10.1063/1.4944072] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Because of its structural specificity, rotational spectroscopy has great potential as an analytical tool for characterizing the chemical composition of complex gas mixtures. However, disentangling the individual molecular constituents of a rotational spectrum, especially if many of the lines are entirely new or unknown, remains challenging. In this paper, we describe an empirical approach that combines the complementary strengths of two techniques, broadband chirped-pulse Fourier transform microwave spectroscopy and narrowband cavity Fourier transform microwave spectroscopy, to characterize and assign lines. This procedure, called microwave spectral taxonomy, involves acquiring a broadband rotational spectrum of a rich mixture, categorizing individual lines based on their relative intensities under series of assays, and finally, linking rotational transitions of individual chemical compounds within each category using double resonance techniques. The power of this procedure is demonstrated for two test cases: a stable molecule with a rich spectrum, 3,4-difluorobenzaldehyde, and products formed in an electrical discharge through a dilute mixture of C2H2 and CS2, in which spectral taxonomy has enabled the identification of propynethial, HC(S)CCH.
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Affiliation(s)
- Kyle N Crabtree
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
| | - Marie-Aline Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | | | - Taylor M Hall
- Coker College, Hartsville, South Carolina 29550, USA
| | - Michael C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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24
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Transue WJ, Velian A, Nava M, Martin-Drumel MA, Womack CC, Jiang J, Hou GL, Wang XB, McCarthy MC, Field RW, Cummins CC. A Molecular Precursor to Phosphaethyne and Its Application in Synthesis of the Aromatic 1,2,3,4-Phosphatriazolate Anion. J Am Chem Soc 2016; 138:6731-4. [DOI: 10.1021/jacs.6b03910] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Wesley J. Transue
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexandra Velian
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Matthew Nava
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | | | - Caroline C. Womack
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jun Jiang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Gao-Lei Hou
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Xue-Bin Wang
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Michael C. McCarthy
- Harvard−Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, United States
| | - Robert W. Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Christopher C. Cummins
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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25
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McCarthy MC, Martinez O, McGuire BA, Crabtree KN, Martin-Drumel MA, Stanton JF. Isotopic studies of trans- and cis-HOCO using rotational spectroscopy: Formation, chemical bonding, and molecular structures. J Chem Phys 2016; 144:124304. [DOI: 10.1063/1.4944070] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Oscar Martinez
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Brett A. McGuire
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
- National Radio Astronomy Observatory, Charlottesville, Virginia 22901, USA
| | - Kyle N. Crabtree
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Marie-Aline Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA and School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - John F. Stanton
- Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165, USA
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26
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Martin-Drumel MA, McCarthy MC, Patterson D, McGuire BA, Crabtree KN. Automated microwave double resonance spectroscopy: A tool to identify and characterize chemical compounds. J Chem Phys 2016; 144:124202. [DOI: 10.1063/1.4944089] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Marie-Aline Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA
- School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA
- School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - David Patterson
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Brett A. McGuire
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA
- National Radio Astronomy Observatory, Charlottesville, Virginia 22903, USA
| | - Kyle N. Crabtree
- Department of Chemistry, University of California, Davis, Davis, California 95616, USA
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27
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Cernicharo J, McCarthy MC, Gottlieb CA, Agúndez M, Velilla Prieto L, Baraban JH, Changala PB, Guélin M, Kahane C, Martin-Drumel MA, Patel NA, Reilly NJ, Stanton JF, Quintana-Lacaci G, Thorwirth S, Young KH. Discovery of SiCSi in IRC +10216: A missing link between gas and dust carriers of Si-C bonds. Astrophys J Lett 2015; 806:L3. [PMID: 26722621 PMCID: PMC4693961 DOI: 10.1088/2041-8205/806/1/l3] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report the discovery in space of a disilicon species, SiCSi, from observations between 80 and 350 GHz with the IRAM 30m radio telescope. Owing to the close coordination between laboratory experiments and astrophysics, 112 lines have now been detected in the carbon-rich star CW Leo. The derived frequencies yield improved rotational and centrifugal distortion constants up to sixth order. From the line profiles and interferometric maps with the Submillimeter Array, the bulk of the SiCSi emission arises from a region of 6″ in radius. The derived abundance is comparable to that of SiC2. As expected from chemical equilibrium calculations, SiCSi and SiC2 are the most abundant species harboring a Si-C bond in the dust formation zone and certainly both play a key role in the formation of SiC dust grains.
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Affiliation(s)
- J Cernicharo
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - M C McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - C A Gottlieb
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - M Agúndez
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - L Velilla Prieto
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - J H Baraban
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309
| | - P B Changala
- JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, CO 80309
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, F-38406, St-Martin d'Hères, France
| | - C Kahane
- Universit Grenoble Alpes, IPAG, F-38000 Grenoble, France; CNRS, IPAG, F-38000 Grenoble, France
| | - M A Martin-Drumel
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - N A Patel
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - N J Reilly
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
| | - J F Stanton
- Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin, Austin, TX 78712
| | - G Quintana-Lacaci
- Group of Molecular Astrophysics. ICMM. CSIC. C/Sor Juana Inés de La Cruz N3. E-28049, Madrid. Spain
| | - S Thorwirth
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
| | - K H Young
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, and School of Engineering & Applied Sciences, Harvard University, Cambridge, MA 02138
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28
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McCarthy MC, Baraban JH, Changala PB, Stanton JF, Martin-Drumel MA, Thorwirth S, Gottlieb CA, Reilly NJ. Discovery of a Missing Link: Detection and Structure of the Elusive Disilicon Carbide Cluster. J Phys Chem Lett 2015; 6:2107-2111. [PMID: 26266510 DOI: 10.1021/acs.jpclett.5b00770] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The rotational spectrum of the elusive but fundamentally important silicon carbide SiCSi has been detected using sensitive microwave techniques aided by high-level ab initio methods. Its equilibrium structure has been determined to very high precision using isotopic substitution and vibrational corrections calculated quantum-chemically: it is an isosceles triangle with a Si-C bond length of 1.693(1) Å, and an apex angle of 114.87(5)°. Now that all four Si(m)C(n) clusters with m + n = 3 have been observed experimentally, their structure and chemical bonding can be rigorously compared. Because Si2C is so closely linked to other Si-bearing molecules that have been detected in the evolved carbon star IRC+10216, it is an extremely promising candidate for detection with radio telescopes.
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Affiliation(s)
| | - Joshua H Baraban
- ‡Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - P Bryan Changala
- ¶JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - John F Stanton
- §Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | | | - Sven Thorwirth
- ∥I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany
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29
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Womack CC, Martin-Drumel MA, Brown GG, Field RW, McCarthy MC. Observation of the simplest Criegee intermediate CH2OO in the gas-phase ozonolysis of ethylene. Sci Adv 2015; 1:e1400105. [PMID: 26601145 PMCID: PMC4643816 DOI: 10.1126/sciadv.1400105] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 02/06/2015] [Indexed: 06/05/2023]
Abstract
Ozonolysis is one of the dominant oxidation pathways for tropospheric alkenes. Although numerous studies have confirmed a 1,3-cycloaddition mechanism that generates a Criegee intermediate (CI) with form R1R2COO, no small CIs have ever been directly observed in the ozonolysis of alkenes because of their high reactivity. We present the first experimental detection of CH2OO in the gas-phase ozonolysis of ethylene, using Fourier transform microwave spectroscopy and a modified pulsed nozzle, which combines high reactant concentrations with rapid sampling and sensitive detection. Nine other product species of the O3 + C2H4 reaction were also detected, including formaldehyde, formic acid, dioxirane, and ethylene ozonide. The presence of all these species can be attributed to the unimolecular and bimolecular reactions of CH2OO, and their abundances are in qualitative agreement with published mechanisms and rate constants.
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Affiliation(s)
- Caroline C. Womack
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Gordon G. Brown
- Department of Science and Mathematics, Coker College, Hartsville, SC 29550, USA
| | - Robert W. Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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30
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Martin-Drumel MA, Pirali O, Vervloet M. Synchrotron based FT-FIR pure rotational spectroscopy of the NH2 radical in its two lowest vibrational states. J Phys Chem A 2014; 118:1331-8. [PMID: 24475733 DOI: 10.1021/jp406618s] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Six Fourier-transform FIR spectra of the NH2 radical have been recorded at high resolution (0.001 cm(-1)) using synchrotron radiation on the AILES beamline at SOLEIL Synchrotron. Three different experimental discharge setups have been used to observe, in absorption, 1009 pure rotational transitions of NH2 in the vibrational ground state (000) and 170 pure rotational transitions within the first excited vibrational state (010). These results constitute a significant extension of the observed quantum numbers for these two states. The spectra permitted several couplings to be resolved (asymmetric coupling, spin-rotation coupling, hyperfine structure) for relatively highly excited energy levels. An effective fit has been realized using both standard Watson-S and -A reductions despite an abnormal centrifugal distortion effect for this light hydride.
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Affiliation(s)
- M A Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay, UMR 8214 CNRS, Univ. Paris Sud , 91405 Orsay Cedex, France
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31
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Martin-Drumel MA, Pirali O, Balcon D, Bréchignac P, Roy P, Vervloet M. High resolution far-infrared Fourier transform spectroscopy of radicals at the AILES beamline of SOLEIL synchrotron facility. Rev Sci Instrum 2011; 82:113106. [PMID: 22128965 DOI: 10.1063/1.3660809] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Experimental far-infrared (FIR) spectroscopy of transient species (unstable molecules, free radicals, and ions) has been limited so far in both emission and absorption (mainly by the low probability of spontaneous emission in that spectral range and the low brightness of continuum sources used for absorption measurements, respectively). Nevertheless, the FIR spectral range recently became of high astrophysical relevance thanks to several new observational platforms (HERSCHEL, ALMA...) dedicated to the study of this region suitable for the detection of the emission from cold objects of the interstellar medium. In order to complete the experimental dataset concerning transient species, three discharge experiments dedicated to the recording of high resolution FIR spectra of radicals have been developed at the Advanced Infrared Line Exploited for Spectroscopy (AILES) which extracts the bright FIR synchrotron continuum of the synchrotron facility SOLEIL. These experiments make use of a high resolution (R = 0.001 cm(-1)) Bruker IFS125 Fourier transform (FT) spectrometer. An emission setup (allowing to record spectra of radicals excited at high rotational and vibrational temperatures) and two absorption setups (exploiting the bright synchrotron source at the highest resolution available on the FT) are alternatively connected to the FT. The advantages and limitations of these techniques are discussed on the basis of the recent results obtained on OH and CH radicals. These results constitute the first FIR spectra of radicals using synchrotron radiation, and the first FIR spectrum of a C-bearing radical using FT-spectroscopy.
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Affiliation(s)
- M A Martin-Drumel
- Institut des Sciences Moléculaires (ISMO), CNRS, Université Paris XI, ba^t. 210, 91405 Orsay Cedex, France.
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32
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Yu S, Pearson JC, Drouin BJ, Sung K, Pirali O, Vervloet M, Martin-Drumel MA, Endres CP, Shiraishi T, Kobayashi K, Matsushima F. Submillimeter-wave and far-infrared spectroscopy of high-J transitions of the ground and ν2=1 states of ammonia. J Chem Phys 2010; 133:174317. [DOI: 10.1063/1.3499911] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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