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Richardson V, Sundelin D, Romanzin C, Thissen R, Alcaraz C, Polášek M, Guillemin JC, Žabka J, Geppert WD, Ascenzi D. Combined experimental and computational study of the reactivity of the methanimine radical cation (H 2CNH˙ +) and its isomer aminomethylene (HCNH 2˙ +) with propene (CH 3CHCH 2). Phys Chem Chem Phys 2024; 26:22990-23002. [PMID: 39171672 DOI: 10.1039/d4cp02002b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
The gas phase reactivity of the radical cation isomers H2CNH˙+ (methanimine) and HCNH2˙+ (aminomethylene) with propene (CH3CHCH2) has been investigated by measuring absolute reactive cross sections and product branching ratios, under single collision conditions, as a function of collision energy (in the range ∼0.07-11.80 eV) using guided ion beam mass spectrometry coupled with VUV photoionization for selective isomer generation. Experimental results have been merged with theoretical calculations to elucidate reaction pathways and structures of products. The H2CNH˙+ isomer is over a factor two more reactive than HCNH2˙+. A major channel from both isomers is production of protonated methanimine CH2NH2+via hydrogen-atom transfer reaction but, while H2CNH˙+ additionally gives charge and proton transfer products, the HCNH2˙+ isomer leads instead to protonated vinylimine CH2CHCHNH2+, produced alongside CH3˙ radicals. The reactions have astrochemical implications in the build up of chemical complexity in both the interstellar medium and the hydrocarbon-rich atmospheres of planets and satellites.
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Affiliation(s)
- Vincent Richardson
- Department of Physics, The Oliver Lodge, University of Liverpool, Oxford St, Liverpool, L69 7ZE, UK.
- Department of Physics, University of Trento, Via Sommarive 14, I-38123, Trento, Italy.
| | - David Sundelin
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - Claire Romanzin
- Institut de Chimie Physique, UMR8000, CNRS, Université Paris-Saclay, Orsay, France
- Synchrotron Soleil, L'Orme des Merisiers, Saint Aubin, France
| | - Roland Thissen
- Institut de Chimie Physique, UMR8000, CNRS, Université Paris-Saclay, Orsay, France
- Synchrotron Soleil, L'Orme des Merisiers, Saint Aubin, France
| | - Christian Alcaraz
- Institut de Chimie Physique, UMR8000, CNRS, Université Paris-Saclay, Orsay, France
- Synchrotron Soleil, L'Orme des Merisiers, Saint Aubin, France
| | - Miroslav Polášek
- J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, Czechia
| | - Jean-Claude Guillemin
- Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, F-35000 Rennes, France
| | - Jan Žabka
- J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, Czechia
| | - Wolf D Geppert
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - Daniela Ascenzi
- Department of Physics, University of Trento, Via Sommarive 14, I-38123, Trento, Italy.
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2
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Zanchet A, Roncero O, Karabulut E, Solem N, Romanzin C, Thissen R, Alcaraz C. The role of intersystem crossing in the reactive collision of S+(4S) with H2. J Chem Phys 2024; 161:044302. [PMID: 39037135 DOI: 10.1063/5.0214447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 07/05/2024] [Indexed: 07/23/2024] Open
Abstract
We report a study on the reactive collision of S+(4S) with H2, HD, and D2 combining guided ion beam experiments and quantum-mechanical calculations. It is found that the reactive cross sections reflect the existence of two different mechanisms, one being spin-forbidden. Using different models, we demonstrate that the spin-forbidden pathway follows a complex mechanism involving three electronic states instead of two as previously thought. The good agreement between theory and experiment validates the methodology employed and allows us to fully understand the reaction mechanism. This study also provides new fundamental insights into the intersystem crossing process.
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Affiliation(s)
- Alexandre Zanchet
- Instituto de Física Fundamental, CSIC, Serrano 123, 28006 Madrid, Spain
| | - Octavio Roncero
- Instituto de Física Fundamental, CSIC, Serrano 123, 28006 Madrid, Spain
| | - Ezman Karabulut
- Vocational School of Health Services, Bitlis Eren University, 13000 Bitlis, Turkey
| | - Nicolas Solem
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France and Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
| | - Claire Romanzin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France and Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
| | - Roland Thissen
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France and Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
| | - Christian Alcaraz
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France and Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
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3
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Solem N, Romanzin C, Alcaraz C, Thissen R. An innovative method to identify structural change through ion-molecule collision, making use of Time-Of-Flight measurements and SIMION simulations. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5066. [PMID: 38888354 DOI: 10.1002/jms.5066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 05/06/2024] [Accepted: 05/23/2024] [Indexed: 06/20/2024]
Abstract
Structural change of ions induced by collision with a neutral has been studied in a guided ion beam tandem mass spectrometer, using Time-Of-Flight measurements and SIMION simulation. The exothermic catalytic isomerization of HOC+ to HCO+ is used to explore the new methodology. Isomerization is catalyzed via a proton transport mechanism through the interplay of a neutral molecule, the catalyst. Four different potential catalysts, Ne, D2, CH4, and C18O, were studied at different collision energies. SIMION simulation of the ion path and collision in the instrument leads to the highlight of a specific signature related to the catalytic isomerization in the time-of-flight spectra. This signature is used to identify the experimental conditions where isomerization takes place. Only C18O, at low collision energies, gives a clear signature of catalytic isomerization, and a quantitative estimate of the catalyzed isomerization cross-section and rate constant is derived. This new methodology is sensitive to clear presence of catalyzed isomerization and can be used in instruments designed for cross-section measurements, provided low collision energy is used and ion bunching is available.
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Affiliation(s)
- Nicolas Solem
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, Orsay, 91405, France
| | - Claire Romanzin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, Orsay, 91405, France
| | - Christian Alcaraz
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, Orsay, 91405, France
| | - Roland Thissen
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, Orsay, 91405, France
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4
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Richardson V, Polášek M, Romanzin C, Tosi P, Thissen R, Alcaraz C, Žabka J, Ascenzi D. Reactivity of the Ethenium Cation (C 2H 5+) with Ethyne (C 2H 2): A Combined Experimental and Theoretical Study. Molecules 2024; 29:810. [PMID: 38398562 PMCID: PMC10892252 DOI: 10.3390/molecules29040810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 02/25/2024] Open
Abstract
The gas-phase reaction between the ethyl cation (C2H5+) and ethyne (C2H2) is re-investigated by measuring absolute reactive cross sections (CSs) and branching ratios (BRs) as a function of collision energy, in the thermal and hyperthermal energy range, via tandem-guided ion beam mass spectrometry under single collision conditions. Dissociative photoionization of C2H5Br using tuneable VUV radiation in the range 10.5-14.0 eV is employed to generate C2H5+, which has also allowed us to explore the impact of increasing (vibrational) excitation on the reactivity. Reactivity experiments are complemented by theoretical calculations, at the G4 level of theory, of the relative energies and structures of the most relevant stationary points on the reactive potential energy hypersurface (PES) and by mass-analyzed ion kinetic energy (MIKE) spectrometry experiments to probe the metastable decomposition from the [C4H7]+ PES and elucidate the underlying reaction mechanisms. Two main product channels have been identified at a centre-of-mass collision energy of ∼0.1 eV: (a) C3H3++CH4, with BR = 0.76±0.05 and (b) C4H5++H2, with BR = 0.22±0.02. A third channel giving C2H3+ in association with C2H4 is shown to emerge at both high internal excitation of C2H5+ and high collision energies. From CS measurements, energy-dependent total rate constants in the range 4.3×10-11-5.2×10-10 cm3·molecule-1·s-1 have been obtained. Theoretical calculations indicate that both channels stem from a common covalently bound intermediate, CH3CH2CHCH+, from which barrierless and exothermic pathways exist for the production of both cyclic c-C3H3+ and linear H2CCCH+ isomers of the main product channel. For the minor C4H5+ product, two isomers are energetically accessible: the three-member cyclic isomer c-C3H2(CH3)+ and the higher energy linear structure CH2CHCCH2+, but their formation requires multiple isomerization steps and passages via transition states lying only 0.11 eV below the reagents' energy, thus explaining the smaller BR. Results have implications for the modeling of hydrocarbon chemistry in the interstellar medium and the atmospheres of planets and satellites as well as in laboratory plasmas (e.g., plasma-enhanced chemical vapor deposition of carbon nanotubes and diamond-like carbon films).
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Affiliation(s)
- Vincent Richardson
- Department of Physics, University of Trento, 38123 Trento, Italy; (V.R.); (P.T.)
- Department of Physics, University of Liverpool, Oxford Street, Liverpool L69 7ZE, UK
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejšškova 2155/3, 182 23 Prague, Czech Republic; (M.P.); (J.Ž.)
| | - Claire Romanzin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France; (C.R.); (R.T.); (C.A.)
- Synchrotron Soleil, L’Orme des Merisiers, 91190 Saint-Aubin, France
| | - Paolo Tosi
- Department of Physics, University of Trento, 38123 Trento, Italy; (V.R.); (P.T.)
| | - Roland Thissen
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France; (C.R.); (R.T.); (C.A.)
- Synchrotron Soleil, L’Orme des Merisiers, 91190 Saint-Aubin, France
| | - Christian Alcaraz
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France; (C.R.); (R.T.); (C.A.)
- Synchrotron Soleil, L’Orme des Merisiers, 91190 Saint-Aubin, France
| | - Ján Žabka
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejšškova 2155/3, 182 23 Prague, Czech Republic; (M.P.); (J.Ž.)
| | - Daniela Ascenzi
- Department of Physics, University of Trento, 38123 Trento, Italy; (V.R.); (P.T.)
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5
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Rossi C, Muller G, Thissen R, Romanzin C, Alcaraz C, Gondarry S, Mayer PM, Jacovella U. New light on the imbroglio surrounding the C 8H +6 isomers formed from ionized azulene and naphthalene using ion-molecule reactions. Chem Sci 2023; 15:317-327. [PMID: 38131094 PMCID: PMC10731908 DOI: 10.1039/d3sc03015f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 11/14/2023] [Indexed: 12/23/2023] Open
Abstract
Most polycyclic aromatic hydrocarbons (PAHs) can isomerize with internal energies near to or below the dissociation threshold. The C10H+8 group of ions, made up of the naphthalene (Naph+) and the azulene (Azu+) radical cations, is a prototypical example. C8H+6 isomers are important species in the growth kinetics and formation of complex organic molecules, and more generally fragments from larger PAHs, yet information about C8H+6 structures is scarce and contradictory. Here, ion-molecule reactions were carried out and the tunable photoionization chemical monitoring technique was used to probe the C8H+6 isomers formed upon C2H2-loss from Naph+ and Azu+. The experimental findings were interpreted with the support of ab initio and kinetics calculations. To facilitate the interpretation of these data, chemical reactivity starting from phenylacetylene (PA) was studied. It was found that most of the C8H+6 ions formed from C10H8, in a timescale of 40 μs, are PA+ in the vicinity of the dissociation threshold. No evidence of the pentalene radical cation (PE+) was observed and explanations to reconcile previous results are presented.
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Affiliation(s)
- Corentin Rossi
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay 91405 Orsay France
| | - Giel Muller
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong Wollongong New South Wales 2522 Australia
| | - Roland Thissen
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000 91405 Orsay France
- Synchrotron SOLEIL L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette France
| | - Claire Romanzin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000 91405 Orsay France
- Synchrotron SOLEIL L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette France
| | - Christian Alcaraz
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000 91405 Orsay France
- Synchrotron SOLEIL L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette France
| | - Sandesh Gondarry
- Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa K1N 6N5 Canada
| | - Paul M Mayer
- Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa K1N 6N5 Canada
| | - Ugo Jacovella
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay 91405 Orsay France
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Ascenzi D, Erdmann E, Bolognesi P, Avaldi L, Castrovilli MC, Thissen R, Romanzin C, Alcaraz C, Rabadan I, Mendez L, Díaz-Tendero S, Cartoni A. H 2O˙ + and OH + reactivity versus furan: experimental low energy absolute cross sections for modeling radiation damage. Phys Chem Chem Phys 2023; 25:24643-24656. [PMID: 37665608 DOI: 10.1039/d3cp02772d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Radiotherapy is one of the most widespread and efficient strategies to fight malignant tumors. Despite its broad application, the mechanisms of radiation-DNA interaction are still under investigation. Theoretical models to predict the effects of a particular delivered dose are still in their infancy due to the difficulty of simulating a real cell environment, as well as the inclusion of a large variety of secondary processes. This work reports the first experimental study of the ion-molecule reactions of the H2O˙+ and OH+ ions, produced by photoionization with synchrotron radiation, with a furan (c-C4H4O) molecule, a template for deoxyribose sugar in DNA. The present experiments, performed as a function of the collision energy of the ions and the tunable photoionization energy, provide key parameters for the theoretical modelling of the effect of radiation dose, like the absolute cross sections for producing protonated furan (furanH+) and a radical cation (furan˙+), the most abundant products, which can amount up to 200 Å2 at very low collision energies (<1.0 eV). The experimental results show that furanH+ is more fragile, indicating how the protonation of the sugar component of the DNA may favor its dissociation with possible major radiosensitizing effects. Moreover, the ring opening of furanH+ isomers and the potential energy surface of the most important fragmentation channels have been explored by molecular dynamics simulations and quantum chemistry calculations. The results show that, in the most stable isomer of furanH+, the ring opening occurs via a low energy pathway with carbon-oxygen bond cleavage, followed by the loss of neutral carbon monoxide and the formation of the allyl cation CH2CHCH2+, which instead is not observed in the fragmentation of furan˙+. At higher energies the ring opening through the carbon-carbon bond is accompanied by the loss of formaldehyde, producing HCCCH2+, the most intense fragment ion detected in the experiments. This work highlights the importance of the secondary processes, like the ion-molecule reactions at low energies in the radiation damage due to their very large cross sections, and it aims to provide benchmark data for the development of suitable models to approach this low collision energy range.
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Affiliation(s)
- Daniela Ascenzi
- Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento, Italy
| | - Ewa Erdmann
- Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland
| | - Paola Bolognesi
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015, Monterotondo, Italy
| | - Lorenzo Avaldi
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015, Monterotondo, Italy
| | - Mattea Carmen Castrovilli
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015, Monterotondo, Italy
| | - Roland Thissen
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
| | - Claire Romanzin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
| | - Christian Alcaraz
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405 Orsay, France
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192 Saint Aubin, Gif-sur-Yvette, France
| | - Ismanuel Rabadan
- Department of Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
| | - Luis Mendez
- Department of Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
| | - Sergio Díaz-Tendero
- Department of Chemistry, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
- Institute for Advanced Research in Chemistry (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Antonella Cartoni
- Department of Chemistry, Sapienza University of Rome, P. le Aldo Moro 5, Rome, 00185, Italy.
- Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015, Monterotondo, Italy
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7
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Jacovella U, Rossi C, Romanzin C, Alcaraz C, Thissen R. Monitoring the Light-induced Isomerisation of the Prototypical Polycyclic Aromatic Hydrocarbons C 10 H 8 + through Ion-Molecule Reactions. Chemphyschem 2023; 24:e202200474. [PMID: 36125423 PMCID: PMC10092717 DOI: 10.1002/cphc.202200474] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/20/2022] [Indexed: 01/20/2023]
Abstract
Structural rearrangements in ions are essential for understanding the composition and evolution of energetic and chemically active environments. This study explores the interconversion routes for simple polycyclic aromatic hydrocarbons, namely naphthalene and azulene radical cations (C10 H8 + ), by combining mass spectrometry and vacuum ultraviolet tunable synchrotron radiation through the chemical monitoring technique. Products of ion-molecule reactions are used to probe C10 H8 + structures that are formed as a function of their internal energies. Isomerisation from azulene radical cation towards naphthalene radical cation in a timescale faster than 80 μs was monitored, whereas no reverse isomerisation was observed in the same time window. When energising C10 H8 + with more than 6 eV, the reactivity of C10 H8 + unveils the formation of a new isomeric group with a contrasted reactivity compared with naphthalene and azulene cations. We tentatively assigned these structures to phenylvinylacetylene cations.
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Affiliation(s)
- Ugo Jacovella
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405, Orsay, France
| | - Corentin Rossi
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405, Orsay, France
| | - Claire Romanzin
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405, Orsay, France.,Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Saint Aubin, Gif-sur-Yvette, France
| | - Christian Alcaraz
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405, Orsay, France.,Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Saint Aubin, Gif-sur-Yvette, France
| | - Roland Thissen
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR8000, 91405, Orsay, France.,Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Saint Aubin, Gif-sur-Yvette, France
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8
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Jacovella U, Rossi C, Romanzin C, Alcaraz C, Thissen R. Structural elucidation of C6H4+· using chemical reaction monitoring: Charge transfer versus bond forming reactions. Chemphyschem 2021; 23:e202100871. [PMID: 34951502 DOI: 10.1002/cphc.202100871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 12/23/2021] [Indexed: 11/06/2022]
Abstract
Mass spectrometry is a powerful tool but when used on its own, without specific activation of ions, the ion mass is the single observable and the structural information is absent. One way of retrieving this information is by using ion-molecule reactions. We propose a general method to disentangle isomeric structures by combining mass spectrometry, tunable synchrotron light source, and quantum-chemistry calculations. We use reactive chemical monitoring technique, which consists in tracking reactivity changes as a function of photoionization energy i.e. the ionic structure. We illustrate the power of this technique with charge transfer reactions of C6H4+· isomers with allene and propyne and discuss its universal applicability. Furthermore, we emphasize the special reactivity characteristics of distonic ions, where strong charge transfer reactivity but very limited reactivity involving bond formation and following cleavages were observed and attributed to the unconventional ortho -benzyne distonic cation.
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Affiliation(s)
- Ugo Jacovella
- Université Paris-Saclay, ISMO, Bat. 520, Rue André Rivière, 91405, Orsay, FRANCE
| | - Corentin Rossi
- Université Paris-Saclay, Institut Chimie Physique, FRANCE
| | - Claire Romanzin
- Université Paris-Saclay: Universite Paris-Saclay, Institut Chimie Physique, FRANCE
| | | | - Roland Thissen
- Université Paris-Saclay: Universite Paris-Saclay, Institut Chimie physique, FRANCE
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9
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Derbali I, Thissen R, Alcaraz C, Romanzin C, Zins EL. Study of the Reactivity of CH 3COOH +• and COOH + Ions with CH 3NH 2: Evidence of the Formation of New Peptide-like C(O)-N Bonds. J Phys Chem A 2021; 125:10006-10020. [PMID: 34761946 DOI: 10.1021/acs.jpca.1c06630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acetamide, a small organic compound containing a peptide bond, was observed in the interstellar medium, but reaction pathways leading to the formation of this prebiotic molecule remain uncertain. We investigated the possible formation of a peptide-like bond from the reaction between acetic acid (CH3-COOH) and methylamine (CH3-NH2) that were identified in the interstellar medium. From an experimental point of view, a quadrupole/octopole/quadrupole mass spectrometer was used in combination with synchrotron radiation as a tunable source of VUV photons for monitoring the reactivity of selected ions. Acetic acid was photoionized, and the reactivity of CH3COOH+• as well as COOH+ (produced from either acetic acid or formic acid) ions with neutral CH3NH2 was further studied. With no surprise, charge transfer, proton transfer, and concomitant dissociation processes were found to largely dominate the reactivity. However, a C(O)-N bond formation process between the two reactants was also evidenced, with a weak cross section reaction. From a theoretical point of view, results concerning reactivity and barrier heights were obtained using density functional theory, with the LC-ωPBE range-separated functional in combination with the 6-311++G(d,p) Pople basis set and are in perfect agreement with the experimental data.
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Affiliation(s)
- Imene Derbali
- De la Molécule aux Nano-Objets: Réactivité, Interactions Spectroscopies, MONARIS, Sorbonne Université, CNRS, 75005 Paris, France
| | - Roland Thissen
- Institut de Chimie Physique, UMR 8000, Université Paris-Saclay, CNRS, Bât. 350, 91405 Orsay, France.,SOLEIL Synchrotron, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Christian Alcaraz
- Institut de Chimie Physique, UMR 8000, Université Paris-Saclay, CNRS, Bât. 350, 91405 Orsay, France.,SOLEIL Synchrotron, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Claire Romanzin
- Institut de Chimie Physique, UMR 8000, Université Paris-Saclay, CNRS, Bât. 350, 91405 Orsay, France.,SOLEIL Synchrotron, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Emilie-Laure Zins
- De la Molécule aux Nano-Objets: Réactivité, Interactions Spectroscopies, MONARIS, Sorbonne Université, CNRS, 75005 Paris, France
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10
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Sundelin D, Ascenzi D, Richardson V, Alcaraz C, Polášek M, Romanzin C, Thissen R, Tosi P, Žabka J, Geppert W. The reactivity of methanimine radical cation (H2CNH•+) and its isomer aminomethylene (HCNH2•+) with C2H4. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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11
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The reactivity of methanimine radical cation (H2CNH+) and its isomer aminomethylene (HCNH2+) with methane. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138611] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Garcia GA, Loison JC, Holzmeier F, Gans B, Alcaraz C, Nahon L, Wu X, Zhou X, Bodi A, Hemberger P. Characterisation of the first electronically excited state of protonated acetylene C2H3+ by coincident imaging photoelectron spectroscopy. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1825851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
| | - Jean-Christophe Loison
- Institut des Sciences Moléculaires, UMR 5255 CNRS - Université de Bordeaux, Cedex, France
| | - Fabian Holzmeier
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Wüzburg, Germany
| | - Bérenger Gans
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, Orsay, France
| | - Christian Alcaraz
- Institut de Chimie Physique, CNRS, Université Paris-Saclay, Orsay, France
| | - Laurent Nahon
- Synchrotron SOLEIL, L'Orme des Merisiers, Cedex, France
| | - Xiangkun Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Peoples Republic of China
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Xiaoguo Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Peoples Republic of China
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, Villigen, Switzerland
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13
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Ascenzi D, Romanzin C, Lopes A, Tosi P, Žabka J, Polášek M, Shaffer CJ, Alcaraz C. State-Selected Reactivity of Carbon Dioxide Cations ( CO 2 + ) With Methane. Front Chem 2019; 7:537. [PMID: 31428598 PMCID: PMC6688064 DOI: 10.3389/fchem.2019.00537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 07/15/2019] [Indexed: 11/22/2022] Open
Abstract
The reactivity ofCO 2 + with CD4 has been experimentally investigated for its relevance in the chemistry of plasmas used for the conversion of CO2 in carbon-neutral fuels. Non-equilibrium plasmas are currently explored for their capability to activate very stable molecules (such as methane and carbon dioxide) and initiate a series of reactions involving highly reactive species (e.g., radicals and ions) eventually leading to the desired products. Energy, in the form of kinetic or internal excitation of reagents, influences chemical reactions. However, putting the same amount of energy in a different form may affect the reactivity differently. In this paper, we investigate the reaction ofCO 2 + with methane by changing either the kinetic energy ofCO 2 + or its vibrational excitation. The experiments were performed by a guided ion beam apparatus coupled to synchrotron radiation in the VUV energy range to produce vibrationally excited ions. We find that the reactivity depends on the reagent collision energy, but not so much on the vibrational excitation ofCO 2 + . Concerning the product branching ratios (CD 4 + /CD 3 + /DOCO+) there is substantial disagreement among the values reported in the literature. We find that the dominant channel is the production ofCD 4 + , followed by DOCO+ andCD 3 + , as a minor endothermic channel.
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Affiliation(s)
| | - Claire Romanzin
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud and Paris Saclay, Centre Universitaire Paris-Sud, Orsay, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin—BP 48, Gif-sur-Yvette, France
| | - Allan Lopes
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud and Paris Saclay, Centre Universitaire Paris-Sud, Orsay, France
| | - Paolo Tosi
- Department of Physics, University of Trento, Trento, Italy
| | - Jan Žabka
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, Czechia
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Prague, Czechia
| | - Christopher J. Shaffer
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czechia
| | - Christian Alcaraz
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud and Paris Saclay, Centre Universitaire Paris-Sud, Orsay, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin—BP 48, Gif-sur-Yvette, France
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14
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Pei L, Farrar JM. A Velocity Map Imaging Study of the Reactions of O+ (4S) With CH4. Front Chem 2019; 7:227. [PMID: 31032248 PMCID: PMC6473029 DOI: 10.3389/fchem.2019.00227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 03/22/2019] [Indexed: 11/16/2022] Open
Abstract
We present a velocity map imaging study of the key ion-molecule reactions occurring in the O+(4S3/2) + CH4 (X1A1) system at collision energies of 1.84 and 2.14 eV. In addition to charge transfer to form CH4+ (X2B2), we also present data on formation of CH3+ (X1A1'), for which the experimentally determined images provide clear confirmation that the products arise from dissociative charge transfer rather than hydride transfer. Experimental data are also presented on the formation of HCO+ through a transient [OCH4]+ complex living many rotational periods. Plausible reaction pathways and intermediate structures are presented to give insight into the routes for formation of these reaction products.
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15
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Cernuto A, Pirani F, Martini LM, Tosi P, Ascenzi D. The Selective Role of Long-Range Forces in the Stereodynamics of Ion-Molecule Reactions: The He + +Methyl Formate Case From Guided-Ion-Beam Experiments. Chemphyschem 2018; 19:51-59. [PMID: 29045020 DOI: 10.1002/cphc.201701096] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 12/20/2022]
Abstract
Long-range intermolecular forces play a crucial role in controlling the outcome of ion-molecule chemical reactions, such as those determining the disappearance of organic or inorganic "complex" molecules recently detected in various regions of the interstellar medium due to collisions with abundant interstellar atomic ions (e.g. H+ and He+ ). Theoretical treatments, for example, based on simple capture models, are nowadays often adopted to evaluate the collision-energy dependence of reactive cross sections and the temperature dependent rate coefficients of many ion-molecule reactions. The obtained results are widely used for the modelling of phenomena occurring in different natural environments or technological applications such as astrophysical and laboratory plasmas. Herein it is demonstrated, through a combined experimental and theoretical investigation on a prototype ion-molecule reaction (He+ +methyl formate), that the dynamics, investigated in detail, shows some intriguing features that can lead to rate coefficients at odds with the expectations (e.g. Arrhenius versus anti-Arrhenius behaviour). Therefore, this study casts light on some new and general guidelines to be properly taken into account for a suitable evaluation of rate coefficients of ion-molecule reactions.
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Affiliation(s)
- Andrea Cernuto
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
| | - Fernando Pirani
- Dipartimento di Chimica, Biologia e Biotecnologie, Universitá di Perugia, Via Elce di Sotto 8, Perugia, Italy.,Istituto di Nanotecnologia (CNR NANOTEC), 70126, Bari, Italy
| | - Luca Matteo Martini
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
| | - Paolo Tosi
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
| | - Daniela Ascenzi
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
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16
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Cernuto A, Lopes A, Romanzin C, Cunha de Miranda B, Ascenzi D, Tosi P, Tonachini G, Maranzana A, Polášek M, Žabka J, Alcaraz C. Effects of collision energy and vibrational excitation of CH 3+ cations on its reactivity with hydrocarbons: But-2-yne CH 3CCCH 3 as reagent partner. J Chem Phys 2017; 147:154302. [PMID: 29055295 DOI: 10.1063/1.4990514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The methyl carbocation is ubiquitous in gaseous environments, such as planetary ionospheres, cometary comae, and the interstellar medium, as well as combustion systems and plasma setups for technological applications. Here we report on a joint experimental and theoretical study on the mechanism of the reaction CH3+ + CH3CCCH3 (but-2-yne, also known as dimethylacetylene), by combining guided ion beam mass spectrometry experiments with ab initio calculations of the potential energy hypersurface. Such a reaction is relevant in understanding the chemical evolution of Saturn's largest satellite, Titan. Two complementary setups have been used: in one case, methyl cations are generated via electron ionization, while in the other case, direct vacuum ultraviolet photoionization with synchrotron radiation of methyl radicals is used to study internal energy effects on the reactivity. Absolute reactive cross sections have been measured as a function of collision energy, and product branching ratios have been derived. The two most abundant products result from electron and hydride transfer, occurring via direct and barrierless mechanisms, while other channels are initiated by the electrophilic addition of the methyl cation to the triple bond of but-2-yne. Among the minor channels, special relevance is placed on the formation of C5H7+, stemming from H2 loss from the addition complex. This is the only observed condensation product with the formation of new C-C bonds, and it might represent a viable pathway for the synthesis of complex organic species in astronomical environments and laboratory plasmas.
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Affiliation(s)
- Andrea Cernuto
- Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy
| | - Allan Lopes
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud 11 and Paris Saclay, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France
| | - Claire Romanzin
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud 11 and Paris Saclay, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France
| | | | - Daniela Ascenzi
- Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy
| | - Paolo Tosi
- Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy
| | - Glauco Tonachini
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, Torino I-10125, Italy
| | - Andrea Maranzana
- Department of Chemistry, University of Torino, Via Pietro Giuria, 7, Torino I-10125, Italy
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague 8, Czech Republic
| | - Jan Žabka
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague 8, Czech Republic
| | - Christian Alcaraz
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud 11 and Paris Saclay, Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France
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17
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Gans B, Garcia GA, Holzmeier F, Krüger J, Röder A, Lopes A, Fittschen C, Loison JC, Alcaraz C. Communication: On the first ionization threshold of the C 2H radical. J Chem Phys 2017; 146:011101. [PMID: 28063431 DOI: 10.1063/1.4973383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The slow photoelectron spectrum of the ethynyl radical has been recorded for the first time by using the DESIRS beamline of the SOLEIL synchrotron facility. Ethynyl was generated using a microwave discharge flow tube. The observation of the X+Π3←XΣ+2 transition allowed the first direct measurement of the adiabatic ionization threshold of this radical (EI = 11.641(5) eV). The experimental results are supported by ab initio calculations. Our preliminary investigation of the cationic ground state potential energy surfaces predicts a non-negligible Renner-Teller effect which has not been discussed previously.
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Affiliation(s)
- B Gans
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - G A Garcia
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP 48, F-91192 Gif sur Yvette Cedex, France
| | - F Holzmeier
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - J Krüger
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP 48, F-91192 Gif sur Yvette Cedex, France
| | - A Röder
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - A Lopes
- Laboratoire de Chimie Physique, UMR 8000 CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, Bât. 350, Centre Universitaire Paris-Sud, F-91405 Orsay Cedex, France
| | - C Fittschen
- Université Lille, CNRS, UMR 8522-PC2A-Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France
| | - J-C Loison
- Institut des Sciences Moléculaires, UMR 5255 CNRS, Université de Bordeaux, Bât. A12, 351 cours de la Libération, F-33405 Talence Cedex, France
| | - C Alcaraz
- Laboratoire de Chimie Physique, UMR 8000 CNRS, Univ. Paris-Sud, Univ. Paris-Saclay, Bât. 350, Centre Universitaire Paris-Sud, F-91405 Orsay Cedex, France
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18
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Desrier A, Romanzin C, Lamarre N, Alcaraz C, Gans B, Gauyacq D, Liévin J, Boyé-Péronne S. Experimental and ab initio characterization of HC 3N + vibronic structure. I. Synchrotron-based threshold photo-electron spectroscopy. J Chem Phys 2016; 145:234310. [DOI: 10.1063/1.4972019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Antoine Desrier
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS UMR 8214, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Claire Romanzin
- Laboratoire de Chimie Physique, CNRS UMR 8000, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cédex, France
- Synchrotron SOLEIL, L’Orme des Merisiers, BP 48, Saint-Aubin, FR-91192 Gif sur Yvette Cedex, France
| | - Nicolas Lamarre
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS UMR 8214, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Christian Alcaraz
- Laboratoire de Chimie Physique, CNRS UMR 8000, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cédex, France
- Synchrotron SOLEIL, L’Orme des Merisiers, BP 48, Saint-Aubin, FR-91192 Gif sur Yvette Cedex, France
| | - Bérenger Gans
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS UMR 8214, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Dolores Gauyacq
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS UMR 8214, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
| | - Jacques Liévin
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, CP 160/09, B-1050 Bruxelles, Belgium
| | - Séverine Boyé-Péronne
- Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS UMR 8214, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay, France
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19
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Hrušák J, Paidarová I. Step Towards Modeling the Atmosphere of Titan: State-Selected Reactions of O + with Methane. ORIGINS LIFE EVOL B 2016; 46:419-424. [PMID: 27068153 DOI: 10.1007/s11084-016-9503-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 01/07/2016] [Indexed: 11/26/2022]
Abstract
Methane conversion and in particular the formation of the C-O bond is one of fundamental entries to organic chemistry and it appears to be essential for understanding parts of atmospheric chemistry of Titan, but, in broader terms it might be also relevant for Earth-like exoplanets. Theoretical study of the reactions of methane with atomic oxygen ion in its excited electronic states requires treating simultaneously at least 19 electronic states. Development of a computational strategy that would allow chemically reasonable and computationally feasible treatment of the CH4 (X)/O+ (2D, 2P) system is by far not trivial and it requires careful examination of all the complex features of the corresponding 19 potential energy surfaces. Before entering the discussion of the rich (photo) chemistry, inspection of the long range behavior of the system with focus on electric dipole transition moments is required. Our calculations show nonzero probability for the reactants to decay before entering the multiple avoided crossings region of the [CH4 + O → products]+ reaction. For the CH4/O+ (2P) system non-zero transition moment probabilities occur over the entire range of considered C-O distances (up to 15 Å), while for the CH4/O+ (2D) system these probabilities are lower by one order of magnitude and were found only at C-O distances smaller than 6 Å.
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Affiliation(s)
- J Hrušák
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejškova 3, 182 23, Prague, Czech Republic.
| | - I Paidarová
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejškova 3, 182 23, Prague, Czech Republic
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20
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Lindén F, Alcaraz C, Ascenzi D, Guillemin JC, Koch L, Lopes A, Polášek M, Romanzin C, Žabka J, Zymak I, Geppert WD. Is the Reaction of C3N(-) with C2H2 a Possible Process for Chain Elongation in Titan's Ionosphere? J Phys Chem A 2016; 120:5337-47. [PMID: 27135984 DOI: 10.1021/acs.jpca.6b01746] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of C3N(-) with acetylene was studied using three different experimental setups, a triple quadrupole mass spectrometer (Trento), a tandem quadrupole mass spectrometer (Prague), and the "CERISES" guided ion beam apparatus at Orsay. The process is of astrophysical interest because it can function as a chain elongation mechanism to produce larger anions that have been detected in Titan's ionosphere by the Cassini Plasma Spectrometer. Three major products of primary processes, C2H(-), CN(-), and C5N(-), have been identified, whereby the production of the cyanide anion is probably partly due to collisional induced dissociation. The formations of all these products show considerable reaction thresholds and also display comparatively small cross sections. Also, no strong signals of anionic products for collision energies lower than 1 eV have been observed. Ab initio calculations have been performed to identify possible pathways leading to the observed products of the title reaction and to elucidate the thermodynamics of these processes. Although the productions of CN(-) and C5N(-) are exoergic, all reaction pathways have considerable barriers. Overall, the results of these computations are in agreement with the observed reaction thresholds. Due to the existence of considerable reaction energy barriers and the small observed cross sections, the title reaction is not very likely to play a major role in the buildup of large anions in cold environments like the interstellar medium or planetary and satellite ionospheres.
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Affiliation(s)
- Fredrik Lindén
- Physics Department, Stockholm University , Roslagstullsbacken 21, S-10691 Stockholm, Sweden.,Stockholm University Astrobiology Centre, Stockholm University , Roslagstullsbacken 21, S-10691 Stockholm, Sweden
| | - Christian Alcaraz
- Laboratoire de Chimie Physique, UMR 8000 CNRS - Université Paris Sud et Université Paris-Saclay , 91405 Orsay Cedex, France
| | - Daniela Ascenzi
- Department of Physics, University of Trento , 38123 Povo, Trento, Italy
| | - Jean-Claude Guillemin
- Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes , CNRS, UMR 6226, 11 allée de Beaulieu, CS 50837, 35708 Rennes, France
| | - Leopold Koch
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Allan Lopes
- Laboratoire de Chimie Physique, UMR 8000 CNRS - Université Paris Sud et Université Paris-Saclay , 91405 Orsay Cedex, France
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Claire Romanzin
- Laboratoire de Chimie Physique, UMR 8000 CNRS - Université Paris Sud et Université Paris-Saclay , 91405 Orsay Cedex, France
| | - Jan Žabka
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Illia Zymak
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Wolf D Geppert
- Physics Department, Stockholm University , Roslagstullsbacken 21, S-10691 Stockholm, Sweden.,Stockholm University Astrobiology Centre, Stockholm University , Roslagstullsbacken 21, S-10691 Stockholm, Sweden
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21
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Polášek M, Zins EL, Alcaraz C, Žabka J, Křížová V, Giacomozzi L, Tosi P, Ascenzi D. Selective Generation of the Radical Cation Isomers [CH3CN](•+) and [CH2CNH](•+) via VUV Photoionization of Different Neutral Precursors and Their Reactivity with C2H4. J Phys Chem A 2016; 120:5041-52. [PMID: 26890990 DOI: 10.1021/acs.jpca.5b12757] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Experimental and theoretical studies have been carried out to demonstrate the selective generation of two different C2H3N(+) isomers, namely, the acetonitrile [CH3CN](•+) and the ketenimine [CH2CNH](•+) radical cations. Photoionization and dissociative photoionization experiments from different neutral precursors (acetonitrile and butanenitrile) have been performed using vacuum ultraviolet (VUV) synchrotron radiation in the 10-15 eV energy range, delivered by the DESIRS beamline at the SOLEIL storage ring. For butanenitrile (CH3CH2CH2CN) an experimental ionization threshold of 11.29 ± 0.05 eV is obtained, whereas the appearance energy for the formation of [CH2CNH](•+) fragments is 11.52 ± 0.05 eV. Experimental findings are fully supported by theoretical calculations at the G4 level of theory (ZPVE corrected energies at 0 K), giving a value of 11.33 eV for the adiabatic ionization energy of butanenitrile and an exothermicity of 0.49 for fragmentation into [CH2CNH](•+) plus C2H4, hampered by an energy barrier of 0.29 eV. The energy difference between [CH3CN](•+) and [CH2CNH](•+) is 2.28 eV (with the latter being the lowest energy isomer), and the isomerization barrier is 0.84 eV. Reactive monitoring experiments of the [CH3CN](•+) and [CH2CNH](•+) isomers with C2H4 have been performed using the CERISES guided ion beam tandem mass spectrometer and exploiting the selectivity of ethylene that gives exothermic charge exchange and proton transfer reactions with [CH3CN](•+) but not with [CH2CNH](•+) isomers. In addition, minor reactive channels are observed leading to the formation of new C-C bonds upon reaction of [CH3CN](•+) with C2H4, and their astrochemical implications are briefly discussed.
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Affiliation(s)
- Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Emilie-Laure Zins
- Sorbonne Universités, UPMC Univ. Paris 06, MONARIS, UMR 8233, Université Pierre et Marie Curie , 4 Place Jussieu, case courrier 49, F-75252 Paris Cedex 05, France
| | - Christian Alcaraz
- Laboratoire de Chimie Physique, Bât. 350, UMR 8000, CNRS-Univ. Paris-Sud & Paris-Saclay , Centre Universitaire Paris-Sud, 91405 Orsay Cedex, France.,Synchrotron SOLEIL , L'Orme des Merisiers, Saint-Aubin - BP 48, 91192 Gif-sur-Yvette, France
| | - Ján Žabka
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Věra Křížová
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic , Dolejškova 2155/3, 18223 Prague 8, Czech Republic
| | - Linda Giacomozzi
- Department of Physics, University of Trento , Via Sommarive 14, 38123 Povo, Italy
| | - Paolo Tosi
- Department of Physics, University of Trento , Via Sommarive 14, 38123 Povo, Italy
| | - Daniela Ascenzi
- Department of Physics, University of Trento , Via Sommarive 14, 38123 Povo, Italy
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22
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Holzmeier F, Lang M, Fischer I, Hemberger P, Garcia GA, Tang X, Loison JC. Assignment of high-lying bending mode levels in the threshold photoelectron spectrum of NH2: a comparison between pyrolysis and fluorine-atom abstraction radical sources. Phys Chem Chem Phys 2015; 17:19507-14. [DOI: 10.1039/c5cp02964c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bending mode progression in the photoelectron spectrum of NH2 was observed and assigned up to υ2+ ≤ 5 and Ka+ ≤ 3.
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Affiliation(s)
- F. Holzmeier
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - M. Lang
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - I. Fischer
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - P. Hemberger
- Molecular Dynamics Group
- Paul Scherrer Institut CH-5232 Villigen
- Switzerland
| | | | - X. Tang
- Synchrotron SOLEIL
- 91192 Gif sur Yvette
- France
| | - J.-C. Loison
- ISM
- Université Bordeaux 1
- CNRS
- 33405 Talence Cedex
- France
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