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511 results on '"Jean-Claude Guillemin"'

1. The isomer distribution of C6H6 products from the propargyl radical gas-phase recombination investigated by threshold-photoelectron spectroscopy

Author

Helgi Rafn Hrodmarsson, Gustavo A. Garcia, Lyna Bourehil, Laurent Nahon, Bérenger Gans, Séverine Boyé-Péronne, Jean-Claude Guillemin, and Jean-Christophe Loison

Subjects
Chemistry, QD1-999
Abstract

Abstract The resonance-stabilization of the propargyl radical (C3H3) makes it among the most important reactive intermediates in extreme environments and grants it a long enough lifetime to recombine in both terrestrial combustion media and cold molecular clouds in space. This makes the propargyl self-reaction a pivotal step in the formation of benzene, the first aromatic ring, to eventually lead to polycyclic aromatic hydrocarbons in a variety of environments. In this work, by producing propargyl radicals in a flow tube where propyne reacted with F atoms and probing the reaction products by mass-selected threshold-photoelectron spectroscopy (TPES), we identified eight C6H6 products in total, including benzene. On top of providing the first comprehensive measurements of the branching ratios of the eight identified C6H6 isomers in the propargyl self reaction products (4 mbar, 298 K conditions), this study also highlights the advantages and disadvantages of using isomer-selective TPES to identify and quantify reaction products.

Published
2024
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2. Vacuum Ultraviolet Single Photon Ionization and Decomposition of 2-Aminopropionitrile in Astrophysical Objects

Author

Helgi Rafn Hrodmarsson, Martin Schwell, Nicolas Fray, Jean-Claude Guillemin, Majdi Hochlaf, and Emilie-Laure Zins

Subjects
Astrobiology, Pre-biotic astrochemistry, Photodissociation regions, Quantum-chemical calculations, H II regions, Photoionization, Astrophysics, QB460-466
Abstract

The molecule 2-aminopropionitrile (2-APN; H _3 CCH(NH _2 )CN) is a chiral precursor of the amino acid alanine and could play an important role in the emergence of the homochirality of life. To date, 2-APN has not yet been detected in the interstellar medium. To address the question of its absence, possibly through destruction by vacuum ultraviolet radiation in astrophysical media, we studied its photoionization and dissociative photoionization in the 9–14 eV (89–137 nm) energy range using photoelectron–photoion coincidence spectroscopy with velocity map imaging. Density functional theory calculations were performed at the PBE0/aug-cc-pVTZ level to determine structures for the various cationic fragments identified experimentally. Their appearance energies were calculated. The adiabatic ionization energy (AIE) of 2-APN is AIE = (9.85±0.01) eV and the appearance energy (AE) of the major fragment ion N≡CC(H)NH _2 ^+ is AE = (10.57±0.01) eV. Both ions, 2-APN ^+ and N≡CC(H)NH _2 ^+ , make up more than 90% of the formed ions. N≡CC(H)NH _2 ^+ , an isomer of the protonated HCN dimer, is also formed with high yield in the dissociative photoionization of aminoacetonitrile (NH _2 CH _2 CN), another α -aminonitrile observed in Sgr B2(N). Photoion yield spectra have been calibrated to absolute ionization cross sections. From these, we derive photoionization rates in several typical radiation fields relevant to different astrophysical objects. The rates show that, under almost all explored radiation fields, dissociative ionization is the dominant pathway for photoionization, leading to the loss of a methyl group (CH _3 ) to form the planar thermodynamically stable amino cyano methylidynium ion N≡CC(H)NH _2 ^+ . The observed absence of 2-APN in Sgr B2 could thus be due to dominant dissociative photoionization.

Published
2024
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3. Synthesis and Spectroscopic Characterization of Interstellar Candidate Ethynyl Thiocyanate: HCCSCN

Author

Elena R. Alonso, Aran Insausti, Lucie Kolesniková, Iker León, Brett A. McGuire, Christopher N. Shingledecker, Marcelino Agúndez, José Cernicharo, Víctor M. Rivilla, Carlos Cabezas, Izaskun Jiménez-Serra, Jesús Martín-Pintado, and Jean-Claude Guillemin

Subjects
Microwave spectroscopy, Millimeter-wave spectroscopy, Molecular spectroscopy, Rotational spectroscopy, Interstellar medium, Radio astronomy, Astrophysics, QB460-466
Abstract

This work aims to spectroscopically characterize and provide for the first time direct experimental frequencies of the ground vibrational state and two excited states of the simplest alkynyl thiocyanate (HCCSCN) for astrophysical use. Both microwave (8–16 GHz) and millimeter-wave regions (50–120 GHz) of the spectrum have been measured and analyzed in terms of Watson’s semirigid rotor Hamiltonian. A total of 314 transitions were assigned to the ground state of HCCSCN, and a first set of spectroscopic constants have been accurately determined. Spectral features of the molecule were then searched for in Sgr B2(N), NGC 6334I, G+0.693−0.027, and TMC-1 molecular clouds. Upper limits to the column density are provided.

Published
2024
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4. Synthesis, Characterization and Chemistry of Tetrakis(Propargylisocyanide) Copper(I) Complex

Author

Alexandre Quelhas, Thierry Roisnel, Jean-Claude Guillemin, and Yann Trolez

Subjects
isocyanide, copper, cycloaddition, Ugi reaction, Inorganic chemistry, QD146-197
Abstract

The kinetically unstable propargylisocyanide was reacted with the tetrakis(acetonitrile) copper(I) hexafluorophosphate and the formed complex was then involved in a copper-catalyzed alkyne-azide cycloaddition reaction (CuAAC). After the decomplexation of the adduct, the isocyanide was engaged in a Ugi reaction. By such a complexation, reactions can be carried out on the CC triple bond without the constraint of the instability of the free compound or the competitive reactivity of the isocyanide group.

Published
2023
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5. Rotational Fingerprints of Vinylketene for Astronomical Observations

Author

Lucie Kolesniková, Tereza Uhlíková, Jan Koucký, Kateřina Luková, Dominik Habiger, Patrik Kania, Jean-Claude Guillemin, and Štěpán Urban

Subjects
Catalogs, Molecular spectroscopy, Interstellar molecules, Laboratory astrophysics, Experimental data, Astrophysics, QB460-466
Abstract

A high degree of isomerism in the realm of interstellar molecules stimulates systematic astronomical investigations of members of different families of isomers. Among them, vinyl-bearing compounds have kindled considerable interest due to recent detections of vinylamine, vinylacetylene, and vinylcyanoacetylene. Herein, we open the possibility to search for vinylketene in the interstellar space by means of its rotational transitions. The pure rotational spectrum of the title molecule was recorded in the frequency regions 195–218 and 293–324 GHz and an improved and extended set of spectroscopic parameters has been obtained for the most stable trans conformer. In addition, rotational signatures and molecular constants for the less stable cis form are reported for the first time. We provide a catalog of precise transition frequencies and intensities of vinylketene to the astronomical community and pave the way toward interstellar explorations of C _4 H _4 O isomer family.

Published
2023
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6. Experimental and Computational Studies on the Reactivity of Methanimine Radical Cation (H2CNH+•) and its Isomer Aminomethylene (HCNH2+•) With C2H2

Author

Vincent Richardson, Daniela Ascenzi, David Sundelin, Christian Alcaraz, Claire Romanzin, Roland Thissen, Jean-Claude Guillemin, Miroslav Polášek, Paolo Tosi, Jan Žabka, and Wolf D. Geppert

Subjects
methylene imine, acrylonitrile, vinyl cyanide, rate constant, cross sections, Titan, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
Abstract

Experimental and theoretical studies are presented on the reactivity of the radical cation isomers H2CNH+• (methanimine) and HCNH2+• (aminomethylene) with ethyne (C2H2). Selective isomer generation is performed via dissociative photoionization of suitable neutral precursors as well as via direct photoionization of methanimine. Reactive cross sections (in absolute scales) and product branching ratios are measured as a function of photon and collision energies. Differences between isomers’ reactivity are discussed in light of ab-initio calculations of reaction mechanisms. The major channels, for both isomers, are due to H atom elimination from covalently bound adducts to give [C3NH4]+. Theoretical calculations show that while for the reaction of HCNH2+• with acetylene any of the three lowest energy [C3NH4]+ isomers can form via barrierless and exothermic pathways, for the H2CNH+• reagent the only barrierless pathway is the one leading to the production of protonated vinyl cyanide (CH2CHCNH+), a prototypical branched nitrile species that has been proposed as a likely intermediate in star forming regions and in the atmosphere of Titan. The astrochemical implications of the results are briefly addressed.

Published
2021
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7. High-Resolution Infrared Spectroscopy of DC3N in the Stretching Region

Author

Ningjing Jiang, Mattia Melosso, Filippo Tamassia, Luca Bizzocchi, Luca Dore, Elisabetta Canè, Davide Fedele, Jean-Claude Guillemin, and Cristina Puzzarini

Subjects
cyanoacetylene, interstellar: matter, rovibrational spectroscopy, spectral analysis, infrared spectroscopy, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
Abstract

The perspectives opened by modern ground-based infrared facilities and the forthcoming James Webb Telescope mission have brought a great attention to the ro-vibrational spectra of simple interstellar molecules. In this view, and because of the lack of accurate spectroscopic data, we have investigated the infrared spectrum of deuterated cyanoacetylene (DC3N), a relevant astrochemical species. The ν1, ν2, and ν3 fundamentals as well as their hot-bands were observed in the stretching region (1,500–3,500 cm−1) by means of a Fourier transform infrared spectrometer. Supplementary measurements were performed at millimeter-wavelengths (243–295 GHz) with a frequency-modulation spectrometer equipped with a furnace, that allowed to probe pure rotational transitions in the investigated stretching states. Furthermore, since HC3N is observed as by-product in our spectra and suffers from the same deficiency of accurate infrared data, its ro-vibrational features have been analyzed as well. The combined analysis of both rotational and ro-vibrational data allowed us to determine precise spectroscopic constants that can be used to model the infrared spectra of DC3N and HC3N. The importance of accurate molecular data for the correct modeling of proto-planetary disks and exoplanetary atmospheres is then discussed.

Published
2021
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8. From Molecular to Cluster Properties: Rotational Spectroscopy of 2-Aminopyridine and of Its Biomimetic Cluster with Water

Author

Adam Kraśnicki, Zbigniew Kisiel, and Jean-Claude Guillemin

Subjects
hydrogen bonding, weakly bound clusters, rotational spectroscopy, supersonic expansion, molecular structure, hyperfine splitting, Organic chemistry, QD241-441
Abstract

We report the observation and analysis of the rotational spectrum of a 1:1 cluster between 2-aminopyridine and water (AMW) carried out with supersonic expansion Fourier transform microwave spectroscopy at 4.7–16.5 GHz. Measurements of the 2-aminopyridine monomer (AMP) were also extended up to 333 GHz for the room-temperature rotational spectrum and to resolved hyperfine splitting resulting from the presence of two 14N quadrupolar nuclei. Supersonic expansion measurements for both AMP and AMW were also carried out for two synthesized isotopic species with single deuteration on the phenyl ring. Nuclear quadrupole hyperfine structure has also been resolved for AMW and the derived splitting constants were used as an aid in structural analysis. The structure of the AMW cluster was determined from the three sets of available rotational constants and the hydrogen bonding configuration is compared with those for clusters with water of similarly sized single-ring molecules. Experimental results aided by quantum chemistry computations allow the conclusion that the water molecule is unusually strongly bound by two hydrogen bonds, OH...N and O...HN, to the NCNH atomic chain of AMP with the potential to replace hydrogen bonds to the identical structural segment in cytosine and adenine in CT and AT nucleic acid base pairs.

Published
2021
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11. Millimeter-wave spectrum of 2-propanimine

Author

Luyao Zou, Jean-Claude Guillemin, Arnaud Belloche, Jes K Jørgensen, Laurent Margulès, Roman A Motiyenko, Peter Groner, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), University of Missouri System, This work was supported by the CNES and the Action sur Projets de l’INSU, PCMI, and by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement (H2020-MSCA-IF-2019, Project number 894508)., and European Project: 894508,H2020,H2020-MSCA-IF-2019, CP-FTmmW Aminogen (2020)

Subjects
Chemical Physics (physics.chem-ph), Space and Planetary Science, Physics - Chemical Physics, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, [CHIM]Chemical Sciences, Astronomy and Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Astrophysics of Galaxies
Abstract

Up to date, only 6 imines have been detected in the interstellar medium. The 3-carbon imine, 2-propanimine ((CH$_3$)$_2$C=NH), is predicted to be the structural isomer with the lowest energy in the C$_3$H$_7$N group, and appears to be a good candidate for astronomical searches. Unexpectedly, no microwave or millimeter wave spectrum is available for 2-propanimine. In this work, we provide the first high resolution millimeter wave spectrum of 2-propanimine and its analysis. With the guide of this laboratory measurement, we aim to search for 2-propanimine in two molecule-rich sources Sgr B2(N) and IRAS 16293-2422 using observations from the Atacama Large Millimeter/submillimeter Array (ALMA). Starting from a synthesized sample, we measured the spectrum of 2-propanimine from 50 to 500 GHz, and the ground state lines are successfully assigned and fitted using XIAM and ERHAM programs with the aid of theoretical calculations. The barriers to internal rotation of the two CH$_3$ tops are determined to be 531.956(64) cm$^{-1}$ and 465.013(26) cm$^{-1}$. These data are able to provide reliable prediction of transition frequencies for astronomical search. Although a few line matches exist, no confirmed detection of 2-propanimine has been found in the hot molecular core Sgr B2(N1S) and the Class 0 protostar IRAS 16293B. Upper-limits of its column density have been derived, and indicate that 2-propanimine is at least 18 times less abundant than methanimine in Sgr B2(N1S), and is at most 50-83 % of methanimine in IRAS 16293B., Comment: 14 pages, 10 figures

Published
2023
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12. Methylenecyanamide (CH2═NCN) and (Z)- and (E)-Iminoacetonitriles (NC–CH═NH), Dimers of Hydrogen Cyanide

Author

Hajer Ayachi, Houda Gazzeh, Taoufik Boubaker, Jean-Claude Guillemin, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Monastir - University of Monastir (UM), and The authors thank the Centre National d’Etudes Spatiales (CNES) and the 'Programme National Physique et Chimie du Milieu Interstellaire' (PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES for a grant. H.A. received a fellowship from the University of Monastir.

Subjects
[CHIM.ORGA]Chemical Sciences/Organic chemistry, Organic Chemistry
Abstract

International audience; (Z)- and (E)-iminoacetonitriles (NCCH═NH), two hydrogen cyanide dimers, are described as key compounds in prebiotic chemistry. Among the many possible dimers of HCN with covalent bonds, even the second on the scale of thermodynamic stability, methylenecyanamide (CH(2)═NCN), has been investigated little. We show that this compound can be isolated, is stable enough to give an adduct with a nucleophile or a diene, and can be easily generated under prebiotic conditions, highlighting a possible role in this medium. Comparison between isomers shows significant differences in formation and chemical reactivity.

Published
2023
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13. Rotational spectroscopy of mono-deuterated oxirane (c-C2H3DO) and its detection towards IRAS 16293−2422 B

Author

Holger S P Müller, Jes K Jørgensen, Jean-Claude Guillemin, Frank Lewen, Stephan Schlemmer, Universität zu Köln = University of Cologne, University of Copenhagen = Københavns Universitet (UCPH), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Deutsche Forschungsgemeinschaft [SFB 956, 184018867, SCHL 341/15-1], European Research Council through the ERC Consolidator Grant 'S4F' [646908], Centre for Star and Planet Formation - Danish National Research Foundation, Centre National d'Etudes Spatiales (CNES) [4500065585], Programme National Physique et Chimie du Milieu Interstellaire (PCMI) of CNRS/INSU, INC/INP - CEA, INC/INP - CNES, and European Project: 646908,H2020,ERC-2014-CoG,S4F(2015)

Subjects
laboratory [methods], INTERSTELLAR, ALMA-PILS SURVEY, FOS: Physical sciences, ISM: abundances, methods: laboratory, H2CS, Physics - Chemical Physics, [CHIM]Chemical Sciences, SPECTRA, Physics - Atomic and Molecular Clusters, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), molecules [ISM], Chemical Physics (physics.chem-ph), abundances [ISM], astrochemistry, ETHYLENE-OXIDE, PROTOSTELLAR, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: individual objects: IRAS 16293-2422, ISM: molecules, Astrophysics - Solar and Stellar Astrophysics, individual objects: IRAS 16293-2422 [ISM], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), identification [line], Astrophysics - Instrumentation and Methods for Astrophysics, Atomic and Molecular Clusters (physics.atm-clus), line: identification
Abstract

We prepared a sample of mono-deuterated oxirane and studied its rotational spectrum in the laboratory between 490 GHz and 1060 GHz in order to improve its spectroscopic parameters and consequently the calculated rest frequencies of its rotational transitions. The updated rest frequencies were employed to detect $c$-C$_2$H$_3$DO for the first time in the interstellar medium in the Atacama Large Millimetre/submillimetre Array (ALMA) Protostellar Interferometric Line Survey (PILS) of the Class 0 protostellar system IRAS 16293$-$2422. Fits of the detected lines using the rotation diagrams yield a temperature of $T_{\rm rot} = 103 \pm 19$ K, which in turn agrees well with 125 K derived for the $c$-C$_2$H$_4$O main isotopologue previously. The $c$-C$_2$H$_3$DO to $c$-C$_2$H$_4$O ratio is found to be $\sim$0.15 corresponding to a D-to-H ratio of $\sim$0.036 per H atom which is slightly higher than the D-to-H ratio of species such as methanol, formaldehyde, ketene and but lower than those of the larger complex organic species such as ethanol, methylformate and glycolaldehyde. This may reflect that oxirane is formed fairly early in the evolution of the prestellar cores. The identification of doubly deuterated oxirane isotopomers in the PILS data may be possible judged by the amount of mono-deuterated oxirane and the observed trend that multiply deuterated isotopologues have higher deuteration rates than their mono-deuterated variants., Comment: 10 pages total; Mon. Not. R. Astron. Soc., accepted

Published
2022
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14. Rotational Spectra of Unsaturated Carbon Chains Produced by Pyrolysis: The Case of Propadienone, Cyanovinylacetylene, and Allenylacetylene

Author

Alessio Melli, Mattia Melosso, Luca Bizzocchi, Silvia Alessandrini, Ningjing Jiang, Francesca Tonolo, Salvatore Boi, Giorgia Castellan, Carlotta Sapienza, Jean-Claude Guillemin, Luca Dore, Cristina Puzzarini, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), This work has been supported by MIUR (PRIN Grant Number 202082CE3T) and by the University of Bologna (RFO funds)., Melli, Alessio, Melosso, Mattia, Bizzocchi, Luca, Alessandrini, Silvia, Jiang, Ningjing, Tonolo, Francesca, Boi, Salvatore, Castellan, Giorgia, Sapienza, Carlotta, Guillemin, Jean-Claude, Dore, Luca, and Puzzarini, Cristina

Subjects
Rotational spectroscopy, Carbon-chain, [CHIM]Chemical Sciences, Interstellar specie, Pyrolysi, Molecules, Physical and Theoretical Chemistry, Quantum chemistry, Energy levels, Molecular structure, Pyrolysis, Spectroscopy
Abstract

International audience; Several interstellar molecules are highly reactive unsaturated carbon chains, which are unstable under terrestrial conditions. Laboratory studies in support of their detection in space thus face the issue of how to produce these species and how to correctly model their rotational energy levels. In this work, we introduce a general approach for producing and investigating unsaturated carbon chains by means of selected test cases. We report a comprehensive theoretical/experimental spectroscopic characterization of three species, namely, propadienone, cyanovinylacetylene, and allenylacetylene, all of them being produced by means of flash vacuum pyrolysis of a suitable precursor. For each species, quantum-chemical calculations have been carried out with the aim of obtaining accurate predictions of the missing spectroscopic information required to guide spectral analysis and assignment. Rotational spectra of the title molecules have been investigated up to 400 GHz by using a frequency-modulation millimeter-/submillimeter-wave spectrometer, thus significantly extending spectral predictions over a wide range of frequency and quantum numbers. A comparison between our results and those available in the literature points out the clear need of the reported laboratory measurements at higher frequencies for setting up accurate line catalogs for astronomical searches.

Published
2022
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15. Reactivity of Cytosine with Alkylmercury Ions in the Gas Phase: the Critical Role of the Alkyl Chain

Author

Jean‐Yves Salpin, Violette Haldys, Jean‐Claude Guillemin, Otilia Mó, Manuel Yáñez, M. Merced Montero‐Campillo, UAM. Departamento de Química, Laboratoire Analyse, Modélisation et Matériaux pour la Biologie et l'Environnement (LAMBE - UMR 8587), Université d'Évry-Val-d'Essonne (UEVE)-Institut de Chimie du CNRS (INC)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Universidad Autónoma de Madrid (UAM), and Project PID2021-125207NB-C31 and PID2019-110091GB-I00 from the Ministerio de Ciencia e Innovación (MICINN) of Spain.Université d'Evry Paris-SaclayUniversidade de Vigo (Spain)

Subjects
Cytosine, Pollutants, IRMPD spectroscopy, Mass spectrometry, General Chemistry, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Alkylmercury compounds, Química, DFT calculations
Abstract

The gas-phase reactivity towards cytosine (C) of alkylmercury cations CnH2n+1Hg+, and more particularly CH3Hg+, C2H5Hg+, n-C4H9Hg+ and t-C4H9Hg+, has been studied for the first time by combining tandem mass spectrometry, infrared multiple photon dissociation spectroscopy (IRMPD) and density functional theory (DFT) calculations. Under electrospray conditions, the interaction of C with the cations derived from alkylmercury chloride compounds gives rise to a single type of complex of general formula [RHg(C)]+, except for t-butylmercury which turned to be unreactive. Subsequent MS/MS experiments showed that [RHg]+ ions (R=Me, Et, n-Bu) exhibit a peculiar reactivity characterized by the transfer of the alkyl group, R, to the nucleobase leading to a [(C)R]+ ion, accompanied by the reduction of the metal and loss of 0 Hg. As the length of the alkyl chain increases (n 2), a new fragmentation path leading to protonated cytosine is opened, associated with the elimination of a Cn,H2n,Hg moiety. This latter process is clearly overwhelming with n-BuHg+. The mechanisms associated with both dissociation channels were examined through the use of IRMPD data in the fingerprint region, and by exploring the corresponding potential energy surfaces in the DFT framework, This work has been also supported by the “Fonds pour le Rayonnement de la Recherche (FRR, Université d’Evry Val d’Essonne) and by Project PID2021- 125207NB-C31 and PID2019-110091GB-I00 from the Ministerio de Ciencia e Innovación (MICINN) of Spain. M. M. Montero-Campillo thanks the Ministerio de Universidades for her ARPU (Ayudas para la Recualificación del Profesorado Universitario) fellowship at the Universidade de Vigo (Spain), supported by the Plan de Recuperación, Transformación y Resiliencia. Computational time at Centro de Computación Científica (CCC) of Universidad Autónoma de Madrid is also acknowledged

Published
2023
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16. Formation of CO, CH4, H2CO and CH3CHO through the H2CCO + H surface reaction under interstellar conditions

Author

Mohamad Ibrahim, Jean-Claude Guillemin, Patrick Chaquin, Alexis Markovits, Lahouari Krim, De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Laboratoire de chimie théorique (LCT)

Subjects
[CHIM]Chemical Sciences, General Physics and Astronomy, Physical and Theoretical Chemistry
Abstract

International audience; The reaction of ketene (H2CCO) with hydrogen atoms has been studied under interstellar conditions through two different experimental methods, occurring on the surface and in the bulk of H2CCO ice. We show that ketene interaction with H-atoms at 10 K leads mainly to four reaction products, carbon monoxide (CO), methane (CH4), formaldehyde (H2CO) and acetaldehyde (CH3CHO). A part of these results shows a chemical link between a simple organic molecule such as H2CCO and a complex one such as CH3CHO, through H-addition reactions taking place in dense molecular clouds. The H-addition processes are very often proposed by astrophysical models as mechanisms for the formation of complex organic molecules based on the abundance of species already detected in the interstellar medium. However, the present study shows that the hydrogenation of ketene under non-energetic conditions may also lead efficiently to fragmentation processes and the formation of small species such as CO, CH4 and H2CO, without supplying external energy such as UV photons or high energy particles. Such fragmentation pathways should be included in the astrophysical modeling of H2CCO + H in the molecular clouds of the interstellar medium. To support these results, theoretical calculations have explicitly showed that, under our experimental conditions, H-atom interactions with the C=C bond of ketene lead mainly to CH3CHO, CH4 and CO. By investigating the formation and reactivity of the reaction intermediate H3C-C=O radical, our calculations demonstrate that the H3C-C=O + H reaction evolves through two barrierless pathways to form either CH3CHO or CH4 and CO fragments.

Published
2022
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17. Precursors of the RNA-world in space: Detection of ($Z$)-1,2-ethenediol in the interstellar medium, a key intermediate in sugar formation

Author

Víctor M. Rivilla, Laura Colzi, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Andrés Megías, Mattia Melosso, Luca Bizzocchi, Álvaro López-Gallifa, Antonio Martínez-Henares, Sarah Massalkhi, Belén Tercero, Pablo de Vicente, Jean-Claude Guillemin, Juan García de la Concepción, Fernando Rico-Villas, Shaoshan Zeng, Sergio Martín, Miguel A. Requena-Torres, Francesca Tonolo, Silvia Alessandrini, Luca Dore, Vincenzo Barone, Cristina Puzzarini, Víctor M. Rivilla, Laura Colzi, Izaskun Jiménez-Serra, Jesús Martín-Pintado, Andrés Megía, Mattia Melosso, Luca Bizzocchi, Álvaro López-Gallifa, Antonio Martínez-Henare, Sarah Massalkhi, Belén Tercero, Pablo de Vicente, Jean-Claude Guillemin, Juan García de la Concepción, Fernando Rico-Villa, Shaoshan Zeng, Sergio Martín, Miguel A. Requena-Torre, Francesca Tonolo, Silvia Alessandrini, Luca Dore, Vincenzo Barone, Cristina Puzzarini, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), University of Naples Federico II = Università degli studi di Napoli Federico II, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), Joint ALMA Observatory (JAO), European Southern Observatory (ESO)-National Radio Astronomy Observatory (NRAO), University of Maryland System, Towson University [Towson, MD, United States], Scuola Normale Superiore di Pisa (SNS), PID2019-106235GB-I00, PID2019-107115GB-C21, Comunidad de Madrid: 2019-T1/TIC-15379, MCIN/AEI/10.13039/501100011033, MDM-2017-0737, MDM-2017-0737-19-2, PID2019-105552RB-C41, PRE2019-091471, European Research Council, ERC: 610256, ERC-2013-SyG, Centre National d’Etudes Spatiales, CNES, Centre National de la Recherche Scientifique, CNRS, and European Social Fund, ESF

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Chemical Physics (physics.chem-ph), FOS: Physical sciences, Astronomy and Astrophysics, Interstellar molecules, Molecular cloud, Astrophysics - Astrophysics of Galaxies, Pre-biotic astrochemistry, Space and Planetary Science, Interstellar medium, Astrophysics of Galaxies (astro-ph.GA), Physics - Chemical Physics, [CHIM]Chemical Sciences, Galactic centre, Astrochemistry, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the first detection of ($Z$)-1,2-ethenediol, (CHOH)$_2$, the enol form of glycolaldehyde, in the interstellar medium towards the G+0.693-0.027 molecular cloud located in the Galactic Center. We have derived a column density of (1.8$\pm$0.1)$\times$10$^{13}$ cm$^{-2}$, which translates into a molecular abundance with respect to molecular hydrogen of 1.3$\times$10$^{-10}$. The abundance ratio between glycolaldehyde and ($Z$)-1,2-ethenediol is $\sim$5.2. We discuss several viable formation routes through chemical reactions from precursors such as HCO, H$_2$CO, CHOH or CH$_2$CHOH. We also propose that this species might be an important precursor in the formation of glyceraldehyde (HOCH$_2$CHOHCHO) in the interstellar medium through combination with the hydroxymethylene (CHOH) radical., Accepted for publication in The Astrophysical Journal Letters

Published
2022
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18. Gas-phase spectroscopic identification of the chlorovinyl radical

Author

Carlos Cabezas, Ching-Hua Chang, Jean-Claude Guillemin, Yasuki Endo, Ministry of Science and Technology (Taiwan), Centre National D'Etudes Spatiales (France), Cabezas, Carlos, Guillemin, Jean-Claude, Endo, Yasuki, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), National Chiao Tung University (NCTU), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Ministry of Science and Technology of Taiwan [MOST 104-2113-M-009-202], and Centre National d'Etudes Spatiales (CNES)

Subjects
General Physics and Astronomy, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry
Abstract

7 pags., 4 figs., 3 tabs., Fourier transform microwave spectra for two isomers of the chlorine substituted vinyl radical have been observed in the 4-52 GHz frequency region. The observed radicals (2A') have been generated using electric discharges of diluted dichloro derivatives of ethylene as molecular precursors. Fine and hyperfine components observed for each rotational transition are fully assigned in the present study to two isotopologues (35Cl and 37Cl), and precise molecular constants are determined for both radicals., The present study was supported by the Ministry of Science and Technology of Taiwan, MOST 104-2113-M-009-202. JCG thanks the Centre National d’Etudes Spatiales (CNES) for a grant.

Published
2022
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19. Organic residues in astrophysical ice analogues: Thermal processing of hydrogenated glyoxal ices under interstellar conditions

Author

Jean-Claude Guillemin, Lahouari Krim, Killian Leroux, De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Astrochemistry, astrochemistry, Astronomy and Astrophysics, 02 engineering and technology, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, ISM: molecules, molecular processes, chemistry.chemical_compound, chemistry, 13. Climate action, Space and Planetary Science, methods: laboratory: solid state, 0103 physical sciences, Thermal, [CHIM]Chemical Sciences, Glyoxal, 0210 nano-technology, 010303 astronomy & astrophysics, techniques: spectroscopic
Abstract

International audience; Organic residues are considered as part of the chemical composition of the interstellar dust grains. They are formed under the extreme conditions of the interstellar medium and play an important role in exobiology. They may contain pre-biotic organic species such as amino acids, constituents of proteins and building blocks of DNA and RNA, key elements of life. By investigating the formation of organic residues in an astrophysical context, many groups have been focusing in the UV irradiation and subsequent warm-up of astrophysical ice analogues. This aims to suggest that organic residues are mainly formed in regions of molecular clouds exposed to UV light or cosmic rays. This study shows an organic residue formation involving glyoxal ice and H atoms. While the hydrogenation of glyoxal at 10 K leads mainly to small molecules such as CO and H2CO and CH3OH, we show that the heating of the hydrogenated ice in the 10-300 K temperature range leads to solid residues whose structure is similar to that of glycolaldehyde but they remain stable in solid phase at 300 K and atmospheric pressure. The analysis of the IR data shows that the organic residues formed through the thermal processing of CHOCHO + H reaction would be a mixture of hydroxypyruvaldehyde and methyl glyoxylate, two solid organics whose formation starts with an H-abstraction from glyoxal to form CHOCO• radical which recombines to •CH2OH and •OCH3 radicals. These latter may be formed and trapped in glyoxal ice as secondary products from H2CO + H secondary reaction. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.

Published
2021
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20. Meteoritic amino acids as chemical tracers of parent-body chemistries

Author

F. Pauzat, Y. Ellinger, Brigitte Zanda, Jean-Claude Guillemin, M. Lattelais, Laboratoire de chimie théorique (LCT), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Laboratoire de Minéralogie et Cosmochimie du Muséum (LMCM), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Programme National Physique et Chimie du Milieu Interstellaire (PCMI) of CNRS/Institut National des Sciences de l'Univers (INSU), Institut National de Chimie/Institut National de Planetologie (INC/INP) - CEA, COST Action European Cooperation in Science and Technology (COST) [CM0805], Region Ile de France DIM ACAV (Astrophysique et Conditions d'Apparition de la Vie), CNES Centre National D'etudes Spatiales, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nitrile, Context (language use), Protonation, 010502 geochemistry & geophysics, 01 natural sciences, meteorites, methods: numerical, chemistry.chemical_compound, Chondrite, Computational chemistry, 0103 physical sciences, [CHIM]Chemical Sciences, meteors, meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, chemistry.chemical_classification, Aqueous solution, Astronomy and Astrophysics, Chemical formula, ISM: molecules, Amino acid, chemistry, 13. Climate action, Space and Planetary Science, Carbonaceous chondrite
Abstract

The analysis of the organic matter of meteorites made it possible to identify over 70 amino acids (AA), including 8 of those found in living organisms. However, their relative abundances vary drastically with the type of the carbonaceous chondrite, even for isomers of same chemical formula. In this report, we address the question whether this difference may have its origin in the relative stability of these isomers according to the conditions they experienced when they were formed and after. To this end, we rely on the fact that for most of the species observed so far in the interstellar medium (ISM), the most abundant isomer of a given generic chemical formula is the most stable one (minimum energy principle, MEP). Using quantum density functional theory (DFT) simulations, we investigate the relative stability of the lowest energy isomers of alanine (Ala) and amino butyric acid (ABA) in the neutral, protonated, and zwitterionic structures together with corresponding nitrile precursors. It is shown that β-alanine and γ-ABA are the most stable in a protonated form, whereas α-AA are the most stable in the zwitterionic and nitrile structures. The different composition of the carbonaceous chondrites CIs and CMs could be linked to the chemical context of the aqueous alterations of the parent bodies.

Published
2021
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21. Phosphorescence of C5N− in Rare Gas Solids

Author

Urszula Szczepaniak, Robert Kołos, Jean-Claude Guillemin, Claudine Crépin, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute of Physical Chemistry [Warsaw], Polish Academy of Sciences, Department III, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], luminescence, matrix isolation, anion, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], cyanopolyyne
Abstract

International audience; Phosphorescence of C5N− was discovered following the ArF-laser (193 nm) photolysis of cyanodiacetylene (HC5N) isolated in cryogenic argon, krypton, and xenon matrices. This visible emission, with an origin around 460 nm, is vibrationally resolved, permitting the measurement of frequencies for eight ground-state fundamental vibrational modes, including the three known from previous IR absorption studies. Phosphorescence lifetime amounts to tens or even hundreds of ms depending on the matrix host; it is five times longer than in the case of HC5N.

Published
2022
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22. Spectroscopic and Computational Characterization of 2-Aza-1,3-butadiene, a Molecule of Astrochemical Significance

Author

Ningjing Jiang, Mattia Melosso, Luca Bizzocchi, Silvia Alessandrini, Jean-Claude Guillemin, Luca Dore, Cristina Puzzarini, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), University of Naples Federico II = Università degli studi di Napoli Federico II, Scuola Normale Superiore di Pisa (SNS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), This study was supported by the University of Bologna (RFO funds) as well as by the Italian Space Agency (ASI, 'Life in Space' project, N. 2019-3-U.0). N.J. thanks the China Scholarships Council (CSC) for financial support. J.C.G. thanks the Centre National d’Etudes Spatiales (CNES) and the Program 'Physique et Chimie du Milieu Interstellaire' (INSU-CNRS) for grants., Jiang, Ningjing, Melosso, Mattia, Bizzocchi, Luca, Alessandrini, Silvia, Guillemin, Jean-Claude, Dore, Luca, and Puzzarini, Cristina

Subjects
Butadiene, Polarity, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Molecular structure, Energy levels, Spectroscopy, butadiene, heterodienes, spectroscopy, structure, insterstellar medium
Abstract

International audience; Being N-substituted unsaturated species, azabutadienes are molecules of potential relevance in astrochemistry, ranging from the interstellar medium to Titan’s atmosphere. 2-Azabutadiene and butadiene share a similar conjugated π system, thus allowing investigation of the effects of heteroatom substitution. More interestingly, 2-azabutadiene can be used to proxy the abundance of interstellar butadiene. To enable future astronomical searches, the rotational spectrum of 2-azabutadiene has been investigated up to 330 GHz. The experimental work has been supported and guided by accurate computational characterization of the molecular structure, energetics, and spectroscopic properties of the two possible forms, trans and gauche. The trans species, more stable by about 7 kJ/mol than gauche-2-azabutadiene, has been experimentally observed, and its rotational and centrifugal distortion constants have been obtained with remarkable accuracy, while theoretical estimates of the spectroscopic parameters are reported for gauche-2-azabutadiene.

Published
2022
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23. Phosphorescence of Hydrogen-Capped Linear Polyyne Molecules C8H2, C10H2 and C12H2 in Solid Hexane Matrices at 20 K

Author

Tomonari Wakabayashi, Urszula Szczepaniak, Kaito Tanaka, Satomi Saito, Keisuke Fukumoto, Riku Ohnishi, Kazunori Ozaki, Taro Yamamoto, Hal Suzuki, Jean-Claude Guillemin, Haruo Shiromaru, Takeshi Kodama, Miho Hatanaka, Kindai University, Institute of Physical Chemistry [Warsaw], Polish Academy of Sciences, Department III, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
poyyne, phosphorescence, matrix isolation, electronic transition, molecular vibration, [SHS.CLASS]Humanities and Social Sciences/Classical studies
Abstract

Laser-ablated polyyne molecules, H(C≡C)nH, were separated by size in solutions and co-condensed with excess hexane molecules at a cryogenic temperature of 20 K in a vacuum system. The solid matrix samples containing C8H2, C10H2, and C12H2 molecules were irradiated with UV laser pulses and the phosphorescence 0–0 band was observed at 532, 605, and 659 nm, respectively. Vibrational progression was observed for the symmetric stretching mode of the carbon chain in the ground state with increments of ~2190 cm−1 for C8H2, ~2120 cm−1 for C10H2, and ~2090 cm−1 for C12H2. Temporal decay analysis of the phosphorescence intensity revealed the lifetimes of the triplet state as ~30 ms for C8H2, ~8 ms for C10H2, and ~4 ms for C12H2. The phosphorescence excitation spectrum reproduces UV absorption spectra in the hexane solution and in the gas phase at ambient temperature, although the excitation energy was redshifted. The symmetry-forbidden vibronic transitions were observed for C10H2 by lower excitation energies of 25,500–31,000 cm−1 (320–390 nm). Detailed phosphorescence excitation patterns are discussed along the interaction of the polyyne molecule and solvent molecules of hexane.

Published
2022
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24. Gas-phase identification of (

Author

Mattia, Melosso, Luca, Bizzocchi, Houda, Gazzeh, Francesca, Tonolo, Jean-Claude, Guillemin, Silvia, Alessandrini, Víctor M, Rivilla, Luca, Dore, Vincenzo, Barone, and Cristina, Puzzarini

Subjects
Prebiotics, Molecular Structure, Carbohydrates, Stereoisomerism, Ethylenes
Abstract

Prebiotic sugars are thought to be formed on primitive Earth by the formose reaction. However, their formation is not fully understood and it is plausible that key intermediates could have formed in extraterrestrial environments and subsequently delivered on early Earth by cometary bodies. 1,2-Ethenediol, the enol form of glycolaldehyde, represents a highly reactive intermediate of the formose reaction and is likely detectable in the interstellar medium. Here, we report the identification and first characterization of (

Published
2022

25. Millimeter wave spectroscopy of propynal isotopologues and structure determination

Author

Evan G. Robertson, Mahmut Ruzi, Don McNaughton, Laurent Margulès, Roman A. Motiyenko, Jean-Claude Guillemin, La Trobe University, Erciyes University, Monash university, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), National Computational Infrastructure, NCI: k02, La Trobe University, LTU, Centre National d’Etudes Spatiales, CNES, and Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA

Subjects
Density function theory, Millimeter wave spectroscopy, Interstellar medium, Isotopic substitution, [CHIM]Chemical Sciences, Ab initio calculations, Physical and Theoretical Chemistry, far-IR spectroscopy, Molecular structure, Spectroscopy, Atomic and Molecular Physics, and Optics
Abstract

International audience; Rotational transitions of propynal (HCCCHO) have been measured in the 150–900 GHz region by millimeter wave spectroscopy and in the far infrared region by high resolution FTIR spectroscopy using a synchrotron source. For the parent isotopologue, assignment of MMW transitions up to very high quantum numbers (J = 100, Ka = 25) reveals evidence of extensive perturbations in the ground vibrational state due to Fermi-asymmetry resonance with an excited vibrational state. A fit to nearly 3000 ground state transitions yields effective constants that are suitable for describing relatively unperturbed rotational levels up to Ka = 13. Over 1000 transitions were assigned and fitted for each singly substituted 13C species and nearly 400 transitions for the 18O variant. Re-analysis of literature data on deuterated species, aided by centrifugal distortion constants from hybrid density functional theory calculations at the B2PLYP/aug-cc-pVTZ level, provides a further set of rotational constants. This allows determination of a Rm(2) structure for propynal with the following geometry: r(C≡C) = 1.2066(15), r(C[sbnd]C) = 1.4486(14), r(CO) = 1.2087(10), r(C­H ald) = 1.1069(8), r(C­H acet) = 1.0578(13), θ(CCC) = 176.71(22), θ(OCC) = 123.23(7), θ(HCC ald) = 114.43(31), θ(HCC acet) = 178.45(16). A new Rs structure was also derived.

Published
2023
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27. Millimetre-wave laboratory study of glycinamide and a search for it with ALMA towards Sagittarius B2(N)

Author

Arnaud Belloche, Lech Pszczółkowski, E. Białkowska-Jaworska, Robin T. Garrod, José L. Alonso, Holger S. P. Müller, Jean-Claude Guillemin, Karl M. Menten, Zbigniew Kisiel, Iker León, Elena R. Alonso, L. Kolesniková, Institute of Physics, Polish Academy of Sciences, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Spanish National Research Council (CSIC), Universidad de Valladolid [Valladolid] (UVa), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), University of Virginia, Universität zu Köln = University of Cologne, Max-Planck-Institut für Radioastronomie (MPIFR), National Science Foundation, NSF: AST 19-06489, G61-6, Providence Health Care, PHC, European Research Council, ERC, Deutsche Forschungsgemeinschaft, DFG: 184018867, Centre National d’Etudes Spatiales, CNES, Centre National de la Recherche Scientifique, CNRS, Ministerio de Ciencia e Innovación, MICINN: CTQ2016-76393-P, PID2019-111396GB-I00, Institut de Cardiologie de Montréal, MHI, and Junta de Castilla y León, JCYL: VA077U16, VA244P20

Subjects
Physics, Line: identification, Galactic Center, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, Molecular physics, Spectral line, ISM: molecules, Rotational energy, Astronomical databases: miscellaneous, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Excited state, [CHIM]Chemical Sciences, Sagittarius B2, Rotational spectroscopy, Ground state, Astrophysics::Galaxy Astrophysics, Quantum tunnelling, Astrochemistry, ISM: individual objects: Sagittarius B2
Abstract

Glycinamide is considered to be one of the possible precursors of the simplest amino acid glycine. Its only rotational spectrum reported so far has been in the cm-wave region. The aim of this work is to extend its laboratory spectrum into the mm wave region to support its searches in the ISM. Glycinamide was synthesised chemically and was studied with broadband rotational spectroscopy in the 90-329 GHz region. Tunneling across a low energy barrier between two symmetry equivalent configurations of the molecule resulted in splitting of each vibrational state and many perturbations in associated rotational energy levels, requiring careful coupled state fits for each vibrational doublet. We searched for emission of glycinamide in the imaging spectral line survey ReMoCA performed with ALMA toward Sgr B2(N). We report the first analysis of the mm-wave rotational spectrum of glycinamide, resulting in fitting to experimental measurement accuracy of over 1200 transition frequencies for the ground state tunneling doublet, of many lines for tunneling doublets for two singly excited vibrational states, and determination of precise vibrational separation in each doublet. We did not detect emission from glycinamide in the hot core Sgr B2(N1S). We found that glycinamide is at least seven times less abundant than aminoacetonitrile and 1.8 times less abundant than urea in this source. A comparison with results of astrochemical kinetics models for species related to glycinamide suggests that its abundance may be at least one order of magnitude below the upper limit obtained toward Sgr B2(N1S). This means that glycinamide emission in this source likely lies well below the spectral confusion limit in the frequency range covered by the ReMoCA survey. Targetting sources with a lower level of spectral confusion, such as the Galactic Center shocked region G+0.693-0.027, may be a promising avenue. [abridged], Accepted for publication in A&A

Published
2022
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28. From Molecular to Cluster Properties: Rotational Spectroscopy of 2-Aminopyridine and of Its Biomimetic Cluster with Water

Author

Jean-Claude Guillemin, Adam Kraśnicki, Zbigniew Kisiel, Institute of Physics, Polish Academy of Sciences, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Financial support from a grant from the Polish National Science Centre, decision number DEC/2011/02/A/ST2/00298, and from PHC Polonium 14277ZC grant is acknowledged. The authors also acknowledge the use of computational resources under the grant G61-6 from the Interdisciplinary Center of Mathematical and Computer Modelling (ICM) of Warsaw University. JCG received a grant from the Centre National d’Etudes Spatiales (CNES)., Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, hyperfine splitting, Pharmaceutical Science, molecular structure, 010402 general chemistry, 01 natural sciences, Quantum chemistry, Article, Analytical Chemistry, chemistry.chemical_compound, weakly bound clusters, QD241-441, rotational spectroscopy, 0103 physical sciences, Drug Discovery, Cluster (physics), [CHIM]Chemical Sciences, Molecule, Physical and Theoretical Chemistry, Hyperfine structure, 010304 chemical physics, Hydrogen bond, Organic Chemistry, hydrogen bonding, 0104 chemical sciences, Monomer, chemistry, Chemistry (miscellaneous), Quadrupole, supersonic expansion, Molecular Medicine, Physical chemistry, Rotational spectroscopy
Abstract

We report the observation and analysis of the rotational spectrum of a 1:1 cluster between 2-aminopyridine and water (AMW) carried out with supersonic expansion Fourier transform microwave spectroscopy at 4.7–16.5 GHz. Measurements of the 2-aminopyridine monomer (AMP) were also extended up to 333 GHz for the room-temperature rotational spectrum and to resolved hyperfine splitting resulting from the presence of two 14N quadrupolar nuclei. Supersonic expansion measurements for both AMP and AMW were also carried out for two synthesized isotopic species with single deuteration on the phenyl ring. Nuclear quadrupole hyperfine structure has also been resolved for AMW and the derived splitting constants were used as an aid in structural analysis. The structure of the AMW cluster was determined from the three sets of available rotational constants and the hydrogen bonding configuration is compared with those for clusters with water of similarly sized single-ring molecules. Experimental results aided by quantum chemistry computations allow the conclusion that the water molecule is unusually strongly bound by two hydrogen bonds, OH...N and O...HN, to the NCNH atomic chain of AMP with the potential to replace hydrogen bonds to the identical structural segment in cytosine and adenine in CT and AT nucleic acid base pairs.

Published
2021
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29. Unimolecular decomposition of methyl ketene and its dimer in the gas phase: theory and experiment

Author

Yves Bénilan, Jean-Claude Guillemin, Emilie-Laure Zins, Martin Schwell, Mohammad Esmaïl Alikhani, Lionel Poisson, Imene Derbali, Majdi Hochlaf, Helgi Rafn Hrodmarsson, De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden [Leiden], Laboratoire Imagerie et Systèmes d'Acquisition (LISA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), LUmière et MOlécules (LUMO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Instrumentation, Simulation et Informatique Scientifique (COSYS-LISIS), Université Gustave Eiffel, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Programme National Physique et Chimie du Milieu 63, Centre National de la Recherche Scientifique, proposal ID: 838372, H2020 Marie Skłodowska-Curie Actions, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Universiteit Leiden, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Dimer, General Physics and Astronomy, Context (language use), Photoionization, 010402 general chemistry, 01 natural sciences, Potential energy, Molecular physics, 0104 chemical sciences, chemistry.chemical_compound, Coupled cluster, chemistry, Ionization, 0103 physical sciences, Physics::Atomic and Molecular Clusters, [CHIM]Chemical Sciences, Molecule, Physical and Theoretical Chemistry, Ionization energy, 010303 astronomy & astrophysics
Abstract

International audience; We present a combined theoretical and experimental investigation on the single photoionization and dissociative photoionization of gas-phase methyl ketene (MKE) and its neutral dimer (MKE2). The performed experiments entail the recording of photoelectron photoion coincidence (PEPICO) spectra and slow photoelectron spectra (SPES) in the energy regime 8.7-15.5 eV using linearly polarized synchrotron radiation. We observe both dimerization and trimerization of the monomer which brings about significantly complex and abstruse dissociative ionization patterns. These require the implementation of theoretical calculations to explore the potential energy surfaces of the monomer and dimer's neutral and ionized geometries. To this end, explicitly correlated quantum chemical methodologies involving the coupled cluster with single, double and perturbative triple excitations (R)CCSD(T)-F12 method, are utilized. An improvement in the adiabatic ionization energy of MKE is presented (AIE = 8.937 ± 0.020 eV) as well as appearance energies for multiple fragments formed through dissociative ionization of either the MKE monomer or dimer. In this regard, the synergy of experiment and theory is crucial to interpreting the obtained results. We discuss the potential astrochemical implications of this work in the context of recent advances in the field of astrochemistry and speculate on the potential presence and eventual fate of interstellar MKE molecules.

Published
2020
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30. Direct Experimental Observation of in situ Dehydrogenation of an Amine–Borane System Using Gas Electron Diffraction

Author

João Nunes, Aliyu M. Ja’o, Jean-Claude Guillemin, Derek A. Wann, Sarah L. Masters, Conor D. Rankine, University of Canterbury [Christchurch], University of York [York, UK], Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), EPSRC [EP/1004122, EP/1651146], Federal University Kashere (Nigeria) through the Tertiary Education Trust Fund (TETFund), Dumont d'Urville exchange, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Exergonic reaction, 010304 chemical physics, Hydrogen, chemistry.chemical_element, Boranes, Borane, 010402 general chemistry, Photochemistry, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, Catalysis, Hydrogen storage, chemistry.chemical_compound, chemistry, 13. Climate action, 0103 physical sciences, [CHIM]Chemical Sciences, Dehydrogenation, Amine gas treating, Physical and Theoretical Chemistry
Abstract

International audience; In situ dehydrogenation of azetidine-BH 3 , which is a candidate for hydrogen storage, was observed with the parent and dehydrogenated analogue subjected to rigorous structural and thermochemical investigations. The structural analyses utilized gas electron diffraction supported by high-level quantum calculations, whilst the pathway for the unimolecular hydrogen release reaction in the absence and presence of BH 3 as a bifunctional catalyst was predicted at CBS-QB3 level. The catalyzed dehydrogenation pathway has a barrier lower than the predicted B-N bond dissociation energy, hence favoring the dehydrogenation process over the dissociation of the complex. The predicted enthalpy of dehydrogenation at CCSD(T)/CBS level indicates mild reaction conditions would be required for the hydrogen release and that the compound is closer to thermoneutral than the linear amine boranes. The entropy and free energy change for the dehydrogenation process show that the reaction is exergonic, energetically feasible and will proceed spontaneously towards hydrogen release; all important factors for hydrogen storage.

Published
2019
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31. Spectroscopic Studies on Hydrazine–Boranes, Key Compounds for Chemical Hydrogen Storage

Author

Anna Chrostowska, Javier Torres Escalona, Clovis Darrigan, Jean-Claude Guillemin, Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), French Ministry of Research and Higher Education, Centre National d'Etudes Spatiales (CNES), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010304 chemical physics, Hydrogen, Scope (project management), Methylamine, Hydrazine, chemistry.chemical_element, Boranes, 010402 general chemistry, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Hydrogen storage, Ammonia, chemistry.chemical_compound, chemistry, 0103 physical sciences, [CHIM]Chemical Sciences, Organic chemistry, Physical and Theoretical Chemistry
Abstract

International audience; Hydrazine-boranes (HNNH·BH and HB·NHNH·BH) have been proposed for the storage of hydrogen, but these compounds have not created scope for extensive research works as ammonia- and methylamine-boranes have made these last decades. In the exciting research devoted to energy storage with environmentally friendly processes, hydrazine-borane, hydrazine-bisborane, and their simply substituted derivatives could provide a satisfactory response for hydrogen production and recyclability of the formed products. To date, knowledge of the physical and chemical properties of these compounds is still scarce. In this paper, the electronic structure of various hydrazine-boranes complexes is studied by ultraviolet-photoelectron spectroscopy (UV-PES), which is the experimental technique giving direct access to the energy of occupied molecular orbitals. Thus, UV-PE spectra were registered and first ionization energies were determined. Understanding of different types of interactions between nitrogen lone pairs and their variations by complexation has been our essential goal in these studies. In particular, clear stabilization of all molecular orbital energies is noted when complexation with borane takes place. Evolution of the σ bond during the hydrogen release process upon thermal activation has also been studied experimentally by UV-PES and supported by quantum chemical calculations.

Published
2019
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34. Submillimeter wave spectroscopy of propanoic acid (CH3CH2COOH) and its ISM search

Author

Lucie Kolesniková, O. Dorovskaya, Elena R. Alonso, Vadim V. Ilyushin, Laurent Margulès, José Cernicharo, Belén Tercero, Jean-Claude Guillemin, Roman A. Motiyenko, Eugene A. Alekseev, Institute of Radio Astronomy of NASU [Kharkiv] (IRA), National Academy of Sciences of Ukraine (NASU), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Observatorio Astronomico Nacional, Madrid, Universidad de Valladolid [Valladolid] (UVa), Instituto de Física Fundamental [Madrid] (IFF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Ecole Nationale Supérieure de Chimie de Rennes (ENSCR), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), LM/RAM/JCG acknowledge the support of the Programme National 'Physique et Chimie du Milieu Interstellaire' (PCMI) of CNRS/INSU. JCG thanks also the Centre National d’Etudes Spatiales (CNES) for a grant. BT and JC thank Ministerio de Ciencia e Innovación of Spain (MICIU) for funding support through projects AYA2016-75066-C2-1-P, PID2019-106110 GB-I00, PID2019-107115 GB-C21/ AEI/ 10.13039/501100011033, and PID2019-106235 GB-I00. We also thank ERC for funding through grant ERC2013-Syg-610256-NANOCOSMOS., ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. This work was also based on observations carried out with the IRAM 30-meter telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain)., European Project: 610256,EC:FP7:ERC,ERC-2013-SyG,NANOCOSMOS(2014), Centre National de la Recherche Scientifique (France), Centre National D'Etudes Spatiales (France), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Methods: laboratory: molecular, Methyl acetate, Line: identification, Analytical chemistry, laboratory: molecular [Methods], 010402 general chemistry, 01 natural sciences, Ethyl formate, chemistry.chemical_compound, 0103 physical sciences, Molecule, Physical and Theoretical Chemistry, identification [Line], Spectroscopy, Submillimeter: ISM, molecules [ISM], Physics, 010304 chemical physics, Molecular data, Hydroxyacetone, ISM [Submillimeter], Atomic and Molecular Physics, and Optics, ISM: molecules, 0104 chemical sciences, 3. Good health, Interstellar medium, Propanoic acid, chemistry, 13. Climate action, Excited state, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA]
Abstract

8 pags., 3 figs., 3 tabs., Three compounds with a CHO formula have been detected in the Interstellar Medium (ISM): ethyl formate (CHCHOC(O)H), methyl acetate (CHOC(O)CH) and very recently hydroxyacetone (CHC(O)CHOH). The higher thermodynamic stability of another isomer, the propanoic acid (CHCHC(O)OH), clearly suggests that this molecule should be considered as a possible candidate for ISM detection. To provide reliable predictions for astronomical use in the millimeter and submillimeter wave ranges we performed a new study of propanoic acid rotational spectrum up to 545 GHz. The analysis of large amplitude methyl top torsional motion in this molecule was carried out using the rho axis method and the RAM36 program code. More than 3200 lines corresponding to the rotational transitions in the ground and first excited methyl top torsional states were newly assigned and fit within experimental error. This enabled us to produce new predictions which were used to search for propanoic acid in two high-mass star-forming regions: SgrB2 (public IRAM 30 m) and Orion KL (ALMA Science Verification). We report a non-detection of propanoic acid in these clouds and derive upper limits to the column density., LM/RAM/JCG acknowledge the support of the Programme National “Physique et Chimie du Milieu Interstellaire” (PCMI) of CNRS/INSU. JCG thanks also the Centre National d’Etudes Spatiales (CNES) for a grant. BT and JC thank Ministerio de Ciencia e Innovaci ́on of Spain (MICIU) for funding support through projects AYA2016-75066-C2-1-P, PID2019-106110 GB-I00, PID2019-107115 GB-C21/ AEI/ 10.13039/ 501100011033, and PID2019-106235 GB-I00. We also thank ERC for funding through grant ERC2013-Syg-610256-NANOCOSMOS. This paper makes use of the following ALMA data: ADS/JAO. ALMA⧹♯2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan) with NRC (Canada), NSC, and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. This work was also based on observations carried out with the IRAM 30-meter telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain)

Published
2021
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35. Millimeter- and submillimeter-wave spectrum of trans-formaldoxime (CH2NOH)

Author

Laurent Margulès, Roman A. Motiyenko, Luyao Zou, Jean-Claude Guillemin, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Formamide, Astrochemistry, 010304 chemical physics, Spectrometer, Analytical chemistry, Astronomy and Astrophysics, Context (language use), Astrophysics, 7. Clean energy, 01 natural sciences, chemistry.chemical_compound, chemistry, Space and Planetary Science, Excited state, 0103 physical sciences, Structural isomer, Millimeter, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Ground state, 010303 astronomy & astrophysics
Abstract

Context. Among the six atoms of N-containing molecules with the formula of CH3NO, only formamide (H2NCHO), the most stable structural isomer, has been detected in the interstellar medium (ISM). The formaldoxime isomer may be formed, for example, by the reaction of formaldehyde (H2CO) or methanimine (H2CNH) and hydroxylamine (H2NOH), which are all detected in the ISM. The lack of high accuracy millimeter- and submillimeter-wave measurements hinders the astronomical search for formaldoxime. Aims. The aim of this work is to provide the direct laboratory measurement of the millimeter- and submillimeter-wave spectrum of trans-formaldoxime. Methods. Formaldoxime was synthesized and its rotational spectrum was recorded at room temperature in a glass flow cell using the millimeter- and submillimeter-wave spectrometer in Lille. The SPFIT program in the CALPGM suite was used to fit the spectrum. Results. Rotational lines of trans-formaldoxime from both the ground state and v12 = 1 vibrational excited states have been measured and assigned from 150 to 660 GHz. Spectroscopic constants were derived to the tenth order using both Watson’s A and S reduction Hamiltonian.

Published
2021
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36. An efficient photochemical route towards triplet ethynylphosphinidene, HCCP

Author

Arun‐Libertsen Lawzer, Thomas Custer, Jean‐Claude Guillemin, Robert Kołos, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Ecole Nationale Supérieure de Chimie de Rennes (ENSCR), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
phosphapropadiene, Argon, HCCP, 010405 organic chemistry, Chemistry, Photochemistry, Phosphorus, Matrix isolation, chemistry.chemical_element, Rearrangement, General Medicine, General Chemistry, 010402 general chemistry, 01 natural sciences, Catalysis, 3. Good health, 0104 chemical sciences, Phosphinidene, phosphinidene, [CHIM]Chemical Sciences, Dehydrogenation
Abstract

International audience; While the archetypal free phosphinidene, H-P, has been studied for over a century, reports on uncomplexed, univalent phosphorus compounds are very sparse. Here we demonstrate production of HCCP in solid argon through the UV-induced rearrangement and subsequent dehydrogenation of phosphapropyne, CH 3 CP. Migration of H atoms along the CCP backbone of CH 3 CP resulted in production of the previously unobserved species 1-phosphapropadiene, CH 2 =C=PH, followed by ethynylphosphine, HCCPH 2 .

Published
2021
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37. Structural and thermochemical studies of pyrrolidine borane and piperidine borane by gas electron diffraction and quantum chemical calculations

Author

Sarah L. Masters, Conor D. Rankine, João Nunes, Jean-Claude Guillemin, Aliyu M. Ja’o, Derek A. Wann, University of Canterbury [Christchurch], University of York [York, UK], Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Federal University Kashere (Nigeria) through the Tertiary Education Trust Fund (TETFund), EPSRC Engineering and Physical Sciences Research Council (EPSRC) [EP/I004122, EP/1651146], PHC Dumont d'Urville [34165NB], Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Hydrogen, Amine boranes, 010405 organic chemistry, Chemistry, Gas electron diffraction, chemistry.chemical_element, Boranes, Borane, Hydrogen storage, 010402 general chemistry, Condensed Matter Physics, 7. Clean energy, 01 natural sciences, Bond-dissociation energy, 0104 chemical sciences, Bond length, chemistry.chemical_compound, Computational chemistry, [CHIM]Chemical Sciences, Dehydrogenation, Physical and Theoretical Chemistry
Abstract

International audience; The gaseous structures, thermochemical properties and dehydrogenation reaction energy profiles of the borane complexes of pyrrolidine and piperidine have been investigated using gas electron diffraction (GED) and state-of-the-art computational methods. These complexes are of interest because of their potential as hydrogen storage materials for future onboard transport applications. A comparative structural and thermochemical analysis revealed structures with a slight difference in the essential B-N bond length, with the piperidine borane having a longer bond even though it has a stronger B-N bond according to predicted bond dissociation energies, a trend common with amine boranes. To identify the most favourable dehydrogenation pathway, BH3-catalysed and BH3-uncatalysed dehydrogenation channels have been explored, where the former has been shown to be the favourable process for both complexes. The energy requirements for the hydrogen release reactions are expected to be minimal as evidenced from the calculated dehydrogenation reaction energies, implying their suitability for onboard chemical hydrogen storage.

Published
2021
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38. Rotational spectroscopy of isotopic cyclopropenone, $c$-H$_2$C$_3$O, and determination of its equilibrium structure

Author

Frank Lewen, Stephan Schlemmer, M Ananya Brahmi, Jean-Claude Guillemin, Holger S. P. Müller, Universität zu Köln, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Deutsche Forschungsgemeinschaft German Research Foundation (DFG) [SFB 956, 184018867], Geratezentrum [SCHL 341/15-1], DFG German Research Foundation (DFG) European Commission, Centre National d'Etudes Spatiales (CNES) Centre National D'etudes Spatiales [4500065585], Programme National Physique et Chimie du Milieu Interstellaire (PCMI) of CNRS/INSU, INC/INP - CEA, INC/INP - CNES, Universität zu Köln = University of Cologne, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, molecular data, Analytical chemistry, methods: laboratory: molecular, FOS: Physical sciences, 01 natural sciences, Spectral line, Isotopomers, chemistry.chemical_compound, Physics - Chemical Physics, 0103 physical sciences, Atom, [CHIM]Chemical Sciences, Molecule, Sagittarius B2, Cyclopropenone, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, Chemical Physics (physics.chem-ph), radio lines: ISM, 010304 chemical physics, astrochemistry, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, 3. Good health, chemistry, Deuterium, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Rotational spectroscopy, Astrophysics - Instrumentation and Methods for Astrophysics, techniques: spectroscopic
Abstract

Cyclopropenone was first detected in the cold and less dense envelope of Sagittarius B2(N). It was found later in several cold dark clouds and it may be possible to detect its minor isotopic species in these environments. In addition, the main species may well be identified in warmer environments. We aim to extend existing line lists of isotopologs of c-H2C3O from the microwave to the millimeter region and create one for the singly deuterated isotopolog to facilitate their detections in space. Furthermore, we aim to extend the line list of the main isotopic species to the submillimeter region and to evaluate an equilibrium structure of the molecule. We employed a cyclopropenone sample in natural isotopic composition to investigate the rotational spectra of the main and 18O-containing isotopologs as well as the two isotopomers containing one 13C atom. Spectral recordings of the singly and doubly deuterated isotopic species were obtained using a cyclopropenone sample highly enriched in deuterium. We recorded rotational transitions in the 70-126 GHz and 160-245 GHz regions for all isotopologs and also in the 342-505 GHz range for the main species. Quantum-chemical calculations were carried out to evaluate initial spectroscopic parameters and the differences between ground-state and equilibrium rotational parameters in order to derive semi-empirical equilibrium structural parameters. We determined new or improved spectroscopic parameters for six isotopologs and structural parameters according to different structure models. The spectroscopic parameters are accurate enough to identify minor isotopic species at centimeter and millimeter wavelengths while those of the main species are deemed to be reliable up to 1 THz. Our structural parameters differ from earlier ones. The deviations are attributed to misassignments in the earlier spectrum of one isotopic species., Comment: 11 pages; abstract slightly abbreviated; Astron. Astrophys., in press

Published
2021
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39. Passerini and Ugi Reactions Involving Kinetically Unstable Isocyanides

Author

Houda Gazzeh, Yann Trolez, Alexandre Quelhas, Thierry Roisnel, Jean-Claude Guillemin, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Monastir - University of Monastir (UM), Centre National d'Etudes Spatiales (CNES) Centre National D'etudes Spatiales, Ministère de l'Enseignement Supérieur, de la Recherche et de l'Innovation, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010405 organic chemistry, Chemistry, Organic Chemistry, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, 01 natural sciences, Passerini reaction, 3. Good health, 0104 chemical sciences, Ugi reaction, Organic chemistry, [CHIM]Chemical Sciences, Multicomponent Reaction, Physical and Theoretical Chemistry, Passerini Reaction, Ugi Reaction, Kinetically Unstable Isocyanides
Abstract

International audience; Kinetically unstable isocyanides as vinyl, allenyl and propargyl isocyanides react in Passerini and Ugi reactions faster than they decompose and lead to functionalized alpha-acyloxy amides and alpha-amino amides, respectively, which can subsequently be used in reactions involving the unsaturated substituent.

Published
2021
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40. Hydrogenation of glycolaldehyde to ethylene glycol at 10 K

Author

Lahouari Krim, Jean-Claude Guillemin, Killian Leroux, De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (MONARIS), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Physics, Glycolaldehyde, astrochemistry, Astronomy and Astrophysics, 010402 general chemistry, 01 natural sciences, ISM: molecules, 0104 chemical sciences, chemistry.chemical_compound, molecular processes, chemistry, Space and Planetary Science, 0103 physical sciences, Polymer chemistry, methods: laboratory: solid state, [CHIM]Chemical Sciences, 010303 astronomy & astrophysics, Ethylene glycol, techniques: spectroscopic
Abstract

Glycolaldehyde, the simplest sugar, is a complex organic molecule detected in many regions of the interstellar medium (ISM). Although its synthetic routes are fairly well known and consistent with many laboratory studies, queries still arise about its reactivity and its role in the complex chemistry of the ISM. This study shows the surface and bulk hydrogenation of glycolaldehyde at 10 K in order to confirm or invalidate the astrophysical models which suggest that CHOCH2OH would be a precursor of ethylene glycol through hydrogenation processes occurring on the surface of interstellar dust grains. By coupling IR spectroscopy and mass spectrometry, we show that the formation of HOCH2CH2OH from CHOCH2OH + H solid state reaction occurs, supporting the existence of a chemical link between these two organics in the ISM. This work suggests that while CHO + CH2OH and CH2OH + CH2OH radical recombination would lead to CHOCH2OH and HOCH2CH2OH, respectively, the presence of H-atoms in the ISM would be a secondary source to favour ethylene glycol over glycolaldehyde. These results are in good agreement with different astronomical observations which show simultaneous detections of glycolaldehyde and ethylene glycol with an abundance ratio HOCH2CH2OH/CHOCH2OH ranged between 1 and 15.

Published
2021
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41. Rotational spectroscopic study of S-methyl thioformate: A global laboratory analysis of ground and excited torsional states up to 660 GHz

Author

Isabelle Kleiner, Roman A. Motiyenko, Jean-Claude Guillemin, Laurent Margulès, Belén Tercero, José Cernicharo, Eugene A. Alekseev, Atef Jabri, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lille, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Grant, Centre National d’Etudes Spatiales, ERC-2013Syg-610256-NANOCOSMOS, ERC, AYA2012-32032, MINECO, ASTROMOL CSD 2009-00038, CONSOLIDER-Ingenio, SPECTRORIMI, PCMI/CEA/CNRS, travel Grants, GDR SPECMO 3152, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), National Science Foundation (US), European Southern Observatory, National Institutes of Natural Sciences (Japan), National Research Council of Canada, Ministry of Science and Technology (Taiwan), Academia Sinica (Taiwan), Korea Astronomy and Space Science Institute, ALMA Observatory, National Astronomical Observatory of Japan, National Radio Astronomy Observatory (US), Institut national des sciences de l'Univers (France), Centre National de la Recherche Scientifique (France), Max Planck Society, Instituto Geográfico Nacional (España), European Commission, Ministerio de Economía y Competitividad (España), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Methyl formate, laboratory: molecular [Methods], methods: laboratory: molecular, Context (language use), Astrophysics, 7. Clean energy, 01 natural sciences, Molecular physics, Article, ISM: abundances, chemistry.chemical_compound, 0103 physical sciences, identification [Line], Spectroscopy, 010303 astronomy & astrophysics, Physics, abundances [ISM], [PHYS]Physics [physics], 010304 chemical physics, Spectrometer, ISM [Submillimeter], Astronomy and Astrophysics, Catalogues, Interstellar medium, chemistry, Space and Planetary Science, Excited state, submillimeter: ISM, Ground state, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Microwave, line: identification, catalogs
Abstract

9 pags., 3 figs., 6 tabs., Context. S-methyl thioformate CH3SC(O)H is a monosulfur derivative of methyl formate, a relatively abundant component of the interstellar medium (ISM). S-methyl thioformate being, thermodynamically, the most stable isomer, it can be reasonably proposed for detection in the ISM. Aims. This work aims to experimentally study and theoretically analyze the ground and first torsional excited states for CH3SC(O)H in a large spectral range for astrophysical use. Methods. S-methyl thioformate was synthesized as a result of a reaction of methyl mercaptan with acetic-formic anhydride. The millimeter-wave spectrum was then recorded for the first time from 150 to 660 GHz with the solid-state spectrometer located at Lille. Results. A set of 3545 lines is determined and combined with 54 previously measured lines in the microwave region, belonging to ground state νt = 0 as well as 1391 transitions in the first excited state of torsion ν18 = 1. Some 164 lines were also assigned to ν18 = 2 for the A-species. A global fit was performed using the BELGI-Cs code taking into account the large splitting of A and E lines due to methyl internal rotation motion with a relatively low barrier, V3 = 127.4846(15) cm-1. Conclusions. Using our spectroscopy work, a deep search of S-methyl thioformate was carried out in the IRAM 30 m and ALMA data of different high-mass star-forming regions (Orion KL and Sgr B2). We derived an upper limit to the CH3SC(O)H column density in these regions., This paper makes use of the following ALMA data: ADS/JAO.ALMA #2011.0.00009.SV. ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The results are also based on observations obtained with the IRAM 30 m telescope supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). This work was supported by the Programme National Physique et Chimie du Milieu Intestellaire (PCMI) of CNRS/INSU with INC/INP co-funded by CEA and CNES. B.T. and J.C. thank the ERC for support under grant ERC-2013-Syg-610 256- NANOCOSMOS and the Spanish MINECO for funding support under grants AYA2012-32032 and FIS2014-52172-C2, and the CONSOLIDER-Ingenio program “ASTROMOL” CSD 2009-00038. J.-C.G. thanks the Centre National d’Etudes Spatiales (CNES) for a grant.

Published
2020
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42. Submillimeter-wave spectroscopy and the radio-astronomical investigation of propynethial (HC≡CCHS)

Author

Brett A. McGuire, Corey J. Evans, Laurent Margulès, Roman A. Motiyenko, Donald McNaughton, Andy Wong, A. Remijan, Jean-Claude Guillemin, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), National Radio Astronomy Observatory (NRAO), National Academy of Sciences of Ukraine (NASU), Kharkov National University, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, James Cook University (JCU), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
molecular data, Extrapolation, methods: laboratory: molecular, Astrophysics, 01 natural sciences, Spectral line, chemistry.chemical_compound, symbols.namesake, 0103 physical sciences, Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astronomy and Astrophysics, Quantum number, Propynal, ISM: molecules, Interstellar medium, chemistry, Space and Planetary Science, symbols, submillimeter: ISM, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Hamiltonian (quantum mechanics), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], line: identification, Submillimeter wave
Abstract

Context. The majority of sulfur-containing molecules detected in the interstellar medium (ISM) are analogs of oxygen-containing compounds. Propynal was detected in the ISM in 1988, hence propynethial, its sulfur derivative, is a good target for an ISM search. Aims. Our aim is to measure the rotational spectrum of propynethial and use those measurements to search for this species in the ISM. To date, measurements of the rotational spectra of propynethial have been limited to a small number or transitions below 52 GHz. The extrapolation of the prediction to lines in the milimeter-wave domain is inaccurate and does not provide data to permit an unambiguous detection. Methods. The rotational spectrum was re-investigated up to 630 GHz. Using the new prediction lines of propynethial, as well as the related propynal, a variety of astronomical sources were searched, including star-forming regions and dark clouds. Conclusions. A total of 3288 transitions were newly assigned and fit together with those from previous studies, reaching quantum numbers up to J = 107 and Ka = 24. Watson’s symmetric top Hamiltonian in the Ir representation was used for the analysis, because the molecule is very close to the prolate limit. The search for propynethial resulted in a non-detection; upper limits to the column density were derived in each source.

Published
2020
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43. Millimeter- and submillimeter-wave spectroscopy of thioformamide and interstellar search toward Sgr B2(N)

Author

Laurent Margulès, Robin T. Garrod, Holger S. P. Müller, Arnaud Belloche, Roman A. Motiyenko, Karl M. Menten, Jean-Claude Guillemin, Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Physique Moléculaire aux Interfaces (PMI), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), University of Virginia, Université de Genève = University of Geneva (UNIGE), University of Applied Sciences of Western Switzerland, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), University of Virginia [Charlottesville], University of Geneva [Switzerland], Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Astrochemistry, FOS: Physical sciences, Rotational transition, ISM: individual objects: Sagittarius B2(N), Context (language use), Astrophysics, 01 natural sciences, 7. Clean energy, Molecular physics, Spectral line, 0103 physical sciences, Spectroscopy, 010303 astronomy & astrophysics, Physics, radio lines: ISM, 010304 chemical physics, astrochemistry, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, ISM: molecules, Interstellar medium, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Excited state, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Ground state, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], line: identification
Abstract

Context. Thioformamide NH2CHS is a sulfur-bearing analog of formamide NH2CHO. The latter was detected in the interstellar medium back in the 1970s. Most of the sulfur-containing molecules detected in the interstellar medium are analogs of corresponding oxygen-containing compounds. Therefore, thioformamide is an interesting candidate for a search in the interstellar medium. Aims. A previous study of the rotational spectrum of thioformamide was limited to frequencies below 70 GHz and to transitions with J ≤ 3. The aim of this study is to provide accurate spectroscopic parameters and rotational transition frequencies for thioformamide to enable astronomical searches for this molecule using radio telescope arrays at millimeter wavelengths. Methods. The rotational spectrum of thioformamide was measured and analyzed in the frequency range 150−660 GHz using the Lille spectrometer. We searched for thioformamide toward the high-mass star-forming region Sagittarius (Sgr) B2(N) using the ReMoCA spectral line survey carried out with the Atacama Large Millimeter/submillimeter Array. Results. Accurate rigid rotor and centrifugal distortion constants were obtained from the analysis of the ground state of parent, 34S, 13C, and 15N singly substituted isotopic species of thioformamide. In addition, for the parent isotopolog, the lowest two excited vibrational states, v12 = 1 and v9 = 1, were analyzed using a model that takes Coriolis coupling into account. Thioformamide was not detected toward the hot cores Sgr B2(N1S) and Sgr B2(N2). The sensitive upper limits indicate that thioformamide is nearly three orders of magnitude at least less abundant than formamide. This is markedly different from methanethiol, which is only about two orders of magnitude less abundant than methanol in both sources. Conclusions. The different behavior shown by methanethiol versus thioformamide may be caused by the preferential formation of the latter (on grains) at late times and low temperatures, when CS abundances are depressed. This reduces the thioformamide-to-formamide ratio, because the HCS radical is not as readily available under these conditions.

Published
2020
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44. Phosphorescence excitation mapping and vibrational spectroscopy of HC9N and HC11N cyanopolyynes in organic solvents

Author

Yuma Ohnishi, Claudine Crépin, Kaito Tanaka, Yusuke Morisawa, Tomonari Wakabayashi, Robert Kołos, Hal Suzuki, Urszula Szczepaniak, Jean-Claude Guillemin, Yoriko Wada, Kazunori Ozaki, Polish Academy of Sciences (PAN), Kindai University, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), SYSIPHE, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), The MEXT-Supported Program for the Strategic Research Foundation at Private Universities for Establishing a Best-Energy-Mix Research Center to Promote the Use of Solar Energy, S1411036, subsidized from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) and Kindai University is greatly acknowledged. US is supported by the Mobility Contest Internship Program, Institute of Physical Chemistry, Polish Academy of Sciences for collaboration performed at Kindai University., Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Infrared absorption, Analytical chemistry, chemistry.chemical_element, Infrared spectroscopy, Shpolsky effect, 010402 general chemistry, 01 natural sciences, Matrix isolation, Resonance, Analytical Chemistry, Inorganic Chemistry, chemistry.chemical_compound, symbols.namesake, Raman, Spectroscopy, Cyanopolyyne, 010405 organic chemistry, Phosphorescence, Organic Chemistry, Krypton, [PHYS.PHYS.PHYS-ATM-PH]Physics [physics]/Physics [physics]/Atomic and Molecular Clusters [physics.atm-clus], 0104 chemical sciences, chemistry, Atomic electron transition, symbols, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Raman spectroscopy
Abstract

Cyanopolyyne molecules, HC9N and HC11N, were isolated in solutions and UV, IR, and resonance Raman spectra were measured for the study of their electronic and vibrational properties. Strong signals were observed both in the IR and resonance Raman spectra for the stretching vibrational mode of the sp-hybridized linear carbon chain in the electronic ground state, i.e., σ4 at 2141 cm−1 for HC9N and σ6 at 2105 cm−1 for HC11N. Trapped in cryogenic solid acetonitrile matrix hosts at 20 K, transitions in phosphorescence, a ˜ 3Σ+ → X ˜ 1Σ+, were observed for HC9N at 582.3 nm (0–0) and longer wavelengths and for HC11N at 643.7 nm (0–0) and longer wavelengths. Electronic transitions in the UV, 1Σ+ ← X ˜ 1Σ+, were elucidated by phosphorescence excitation mapping to observe asymmetric patterns with sharp emission-absorption features explainable by Shpolsky effects. For HC9N, three distinct trapping sites were discernible in solid acetonitrile, while the phosphorescence spectra were blurred in solid n-hexane. The observed phosphorescence lifetime of HC9N was longer than that of HC11N, comparable to the trend reported for the series of cyanopolyyne molecules in solid krypton matrix hosts.

Published
2020
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45. Extensive ro-vibrational analysis of deuterated-cyanoacetylene (DC$_3$N) from millimeter-wavelengths to the infrared domain

Author

Jean-Claude Guillemin, L. Colzi, D. Prudenzano, Olivier Pirali, Filippo Tamassia, Luca Bizzocchi, Andrea Pietropolli Charmet, Aleksandra Adamczyk, Barbara M. Giuliano, Marie-Aline Martin-Drumel, Elisabetta Canè, Paola Caselli, Luca Dore, Mattia Melosso, Victor M. Rivilla, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Max-Planck-Institut für Extraterrestrische Physik (MPE), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), University of Ca’ Foscari [Venice, Italy], H2020 Marie Skłodowska-Curie Actions, MSCA 664931Chinese American Ophthalmological Society, CAOS 2015F59J3RCentre National d'Etudes Spatiales, CNESCUP C52I13000140001Horizon 2020 Framework Programme, H2020Max-Planck-Gesellschaft, MPGMinistero dellâIstruzione, dellâUniversità e della Ricerca, MIUR, H2020 Marie Skłodowska-Curie Actions, MSCA 664931Chinese American Ophthalmological Society, CAOS 2015F59J3RCentre National d'Etudes Spatiales, CNESCUP C52I13000140001Horizon 2020 Framework Programme, H2020Max-Planck-Gesellschaft, MPGMinistero dell-Istruzione, Università e Ricerca, MIUR, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), H2020 Marie Skłodowska-Curie Actions, MSCA 664931Chinese American Ophthalmological Society, CAOS 2015F59J3RCentre National d'Etudes Spatiales, CNESCUP C52I13000140001Horizon 2020 Framework Programme, H2020Max-Planck-Gesellschaft, MPGMinistero dell’Istruzione, dell’Università e della Ricerca, MIUR, Melosso M., Bizzocchi L., Adamczyk A., Cane' E., Caselli P., Colzi L., Dore L., Giuliano B.M., Guillemin J.-C., Martin-Drumel M.-A., Pirali O., Pietropolli Charmet A., Prudenzano D., Rivilla V.M., and Tamassia F.

Subjects
010504 meteorology & atmospheric sciences, Infrared, Overtone, FOS: Physical sciences, Anharmonic resonances, Interstellar species, Spectral analysis, 01 natural sciences, Molecular physics, Spectral line, chemistry.chemical_compound, [CHIM]Chemical Sciences, Cyanoacetylene, Isotopologue, Spectroscopy, Astrophysics::Galaxy Astrophysics, Settore CHIM/02 - Chimica Fisica, 0105 earth and related environmental sciences, Ro-vibrational spectroscopy, Physics, Radiation, Cyanopolyyne, Line catalog, Interstellar specie, Astrophysics - Astrophysics of Galaxies, Atomic and Molecular Physics, and Optics, Anharmonic resonance, Deuterium, chemistry, Astrophysics of Galaxies (astro-ph.GA), Millimeter
Abstract

Cyanoacetylene, the simplest cyanopolyyne, is an abundant interstellar molecule commonly observed in a vast variety of astronomical sources. Despite its importance as a potential tracer of the evolution of star-forming processes, the deuterated form of cyanoacetylene is less observed and less studied in the laboratory than the main isotopologue. Here, we report the most extensive spectroscopic characterization of DC$_3$N to date, from the millimeter domain to the infrared region. Rotational and ro-vibrational spectra have been recorded using millimeter-wave frequency-modulation and Fourier-transform infrared spectrometers, respectively. All the vibrational states with energy up to 1015 cm$^{-1}$ have been analyzed in a combined fit, where the effects due to anharmonic resonances have been adequately accounted for. The analysis contains over 6500 distinct transition frequencies, from which all the vibrational energies have been determined with good precision for many fundamental, overtone, and combination states. This work provides a comprehensive line catalog for astronomical observations of DC$_3$N, 14 pages, 3 figures, 8 tables, accepted for publication in JQSRT

Published
2020
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46. Relative thermodynamic stability of the [C,N,O] linkages as an indication of the most abundant structures in the ISM

Author

Jean-Claude Guillemin, O. Matz, Isabelle Fourré, Y. Ellinger, Laboratoire de chimie théorique (LCT), Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)

Subjects
Physics, Astronomy and Astrophysics, Context (language use), Astrophysics, 010402 general chemistry, 01 natural sciences, Chemical formula, Quantum chemistry, ISM: molecules, ISM: abundances, 0104 chemical sciences, Ion, Coupled cluster, Space and Planetary Science, Computational chemistry, 0103 physical sciences, Density functional theory, Chemical stability, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Order of magnitude
Abstract

Context. Most of the compounds detected in the interstellar medium (ISM) that possess isomers correspond to the thermodynamically most stable isomer of a given chemical formula. Using the minimun energy principle (MEP) as a pragmatic tool is particularly efficient for less than six atoms, but for larger systems combinatorial analysis gives an intractable numbers of isomers. Aims. To make the MEP more applicable, we look for a chemical sieve to filter the thermodynamic data needed to determine which isomers of complex organic molecules (COMs) have higher chances of being present in the ISM. To do so, we investigate whether the nature of the [C,N,O] elementary fragment can be determinant for the stabilization of COMs, taking C2H3NO as a case study. Methods. We employed standard quantum chemistry methods to determine the ordering of fragments and derivatives on the energy scale. Density functional theory treatments were systematically performed, together with high-level coupled cluster calculations to refine relative energies. Results. For C2H3NO we find methylisocyanate CH3NCO, which is a compound that was very recently detected in the ISM, to be the most stable isomer in a corpus of 40 isomers of lowest energy. In neutral form we find the stability ordering of NCO > ONC; the same is true for the negative ion. Attachments of R=H, CH3, C2H5, HC2, H2CCH, and C6H5 and metals Al and Mg to the nitrogen atom of the NCO fragment provide the most stable isomers. The energy differences between the successive isomers on the energy scale R-NCO, R-OCN, R-CNO, and R-ONC are of the same order of magnitude for all carbonaceous R. Conclusions. Combining the criterion of most stable linkage with the MEP concept should greatly reduce the window of potential targets to be searched for in the ISM. Compounds containing the NCO linkage should be preferential targets of future research.

Published
2020
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48. VUV photoionization of the CH 2 NC radical: adiabatic ionization energy and cationic vibrational mode wavenumber determinations

Author

Oliver J. Harper, Sebastian Hartweg, Séverine Boyé-Péronne, Gustavo A. Garcia, Jean-Claude Guillemin, Bérenger Gans, Jean-Christophe Loison, Université de Bordeaux, ISM, UMR CNRS 5255, Talence, 33405, France, Institut des Sciences Moléculaires d'Orsay (ISMO), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), This work was performed on the DESIRS beamline under proposal number 20181133. We acknowledge SOLEIL for provisionof synchrotron radiation facilities and the DESIRS beamline staff for their assistance. This work received financial support fromthe French Agence Nationale de la Recherche (ANR) under grant ANR-12-BS08-0020-02 (project SYNCHROKIN). This work wassupported by the Programme National Physique et Chimie du Milieu Interstellaire (PCMI) of CNRS/INSU with INC/INP co-fundedby CEA and CNES. J.-C.G. thanks the CNES for a grant., ANR-12-BS08-0020,SynchroKin,Mise en place d'une technique expérimentale pour la mesure de données cinétiques et mécanistiques utilisant la radiation synchrotron SOLEIL(2012), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], General Physics and Astronomy, 02 engineering and technology, Photoionization, Electron, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, Spectral line, Ion, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Ab initio quantum chemistry methods, Molecular vibration, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Physical and Theoretical Chemistry, Atomic physics, Ionization energy, Physics::Chemical Physics, 0210 nano-technology, 010303 astronomy & astrophysics, Excitation, ComputingMilieux_MISCELLANEOUS
Abstract

The photoelectron spectroscopy of CH2NC (isocyanomethyl) radical species is investigated for the first time between 9.3 and 11.2 eV in the vicinity of the first photoionizing transition X+1A1 ← X 2B1. The experiment combines a microwave discharge flow-tube reactor to produce the radicals through the CH3NC + F → CH2NC + HF reaction, a VUV synchrotron radiation excitation, and a double imaging electron/ion coincidence spectrometer which allows the recording of mass-selected threshold photoelectron spectra. Assignment of the observed vibrational structure of the CH2NC+ cation is guided by ab initio calculations and Franck-Condon simulations. From the experimental spectrum, the first adiabatic ionization energy of the CH2NC radical is measured as 9.439(6) eV. Fundamental wavenumbers are determined for several vibrational modes of the cation [small nu, Greek, tilde]1+(CH2 symmetric stretch) = 2999(80) cm-1, [small nu, Greek, tilde]2+(NC stretch) = 1925(40) cm-1, [small nu, Greek, tilde]4+(H2C-N stretch) = 1193(40) cm-1, [small nu, Greek, tilde]6+(CNC out-of-plane bend) = 237(50) cm-1, and [small nu, Greek, tilde]8+(CH2 rock) = 1185(60) cm-1.

Published
2020
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49. VUV photoionization of the CH

Author

Bérenger, Gans, Sebastian, Hartweg, Gustavo A, Garcia, Séverine, Boyé-Péronne, Oliver J, Harper, Jean-Claude, Guillemin, and Jean-Christophe, Loison

Abstract

The photoelectron spectroscopy of CH

Published
2020

50. Synchrotron-based far-infrared spectroscopy of HC3N: Extended ro-vibrational analysis and new line list up to 3360 cm−1

Author

Filippo Tamassia, Luca Bizzocchi, Mattia Melosso, Marie-Aline Martin-Drumel, Olivier Pirali, Andrea Pietropolli Charmet, Elisabetta Canè, Luca Dore, Iouli E. Gordon, Jean-Claude Guillemin, Barbara M. Giuliano, Paola Caselli, Silvia Alessandrini, Vincenzo Barone, and Cristina Puzzarini

Subjects
Radiation, Spectroscopy, Atomic and Molecular Physics, and Optics
Published
2022
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