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Rajput J, Garg D, Cassimi A, Fléchard X, Rangama J, Safvan CP. Addressing three-body fragmentation of methane dication using "native frames": Evidence of internal excitation in fragments. J Chem Phys 2023; 159:184303. [PMID: 37955322 DOI: 10.1063/5.0171881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/23/2023] [Indexed: 11/14/2023] Open
Abstract
The three body fragmentation of methane dication has been studied using the technique of cold target recoil ion momentum spectroscopy. The process is initiated by impact of energetic Ar9+ ions on neutral methane and the data is subsequently collected in coincidence with Ar8+ projectile. By analysing the dissociation channels leading to (H + H+ + CH2+) and (H + H2+ + CH+) fragments, it is concluded that these fragments are formed in a sequential manner via formation of molecular intermediates CH3+ and CH2+ respectively. It is shown that these molecular intermediates carry a few eVs as their internal energies, part of which is released when they emit an H-atom with the open possibility that the final detected fragments may still be internally excited. This was accomplished by analysing the two-steps of the sequential process in their own native frames. For a molecular system having three-dimensional structure, our results prove to be an ideal example to highlight the importance of using native frames for correct interpretation of the obtained results. Our results indicate that the dissociation of methane dication can be a major source of production of H-atoms in addition to H+ fragments with the probability of the two being of similar order.
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Affiliation(s)
- Jyoti Rajput
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - Diksha Garg
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - X Fléchard
- Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534, F-14000 Caen, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - C P Safvan
- Inter-University Accelerator Centre, New Delhi 110067, India
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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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Yang D, Hu X, Xie D. Quantum dynamics of vibration-vibration energy transfer for vibrationally excited HF colliding with H2. J Comput Chem 2018; 40:1084-1090. [DOI: 10.1002/jcc.25598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 08/20/2018] [Accepted: 08/27/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Dongzheng Yang
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry; School of Chemistry and Chemical Engineering, Nanjing University; Nanjing, 210023 China
| | - Xixi Hu
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry; School of Chemistry and Chemical Engineering, Nanjing University; Nanjing, 210023 China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry; School of Chemistry and Chemical Engineering, Nanjing University; Nanjing, 210023 China
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