1
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Mancini L, Vanuzzo G, Recio P, Caracciolo A, Faginas-Lago N, Rosi M, Casavecchia P, Balucani N. Unveiling the Reaction Mechanism of the N( 2D) + Pyridine Reaction: Ring-Contraction versus 7-Membered-Ring Formation Channels. J Phys Chem A 2024; 128:7177-7194. [PMID: 39141013 DOI: 10.1021/acs.jpca.4c02924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
Despite the relevance of the reactions of the prototypical nitrogen-containing six-membered aromatic molecule (N-heterocyclic) of pyridine (C6H5N) in environmental science, astrochemistry, planetary science, prebiotic chemistry, and materials science, few experimental/theoretical studies exist on the bimolecular reactions involving pyridine and neutral atomic/molecular radicals. We report a combined experimental and theoretical study on the elementary reaction of pyridine with excited nitrogen atoms, N(2D), aimed at providing information about the primary reaction products and their branching fractions (BFs). From previous crossed molecular beam (CMB) experiments with mass-spectrometric detection and present synergistic calculations of the reactive potential energy surface (PES) and product BFs we have unveiled the reaction mechanism. It is found that the reaction proceeds via N(2D) barrierless addition to pyridine that, via bridged intermediates followed by N atom "sliding" into the ring, leads to 7-membered-ring structures. They further evolve, mainly via ring-contraction mechanisms toward 5-membered-ring radical products and, to a smaller extent, via H-displacement mechanisms toward 7-membered-ring isomeric products and their isomers. Using the theoretical statistical estimates, an improved fit of the experimental data previously reported has been obtained, leading to the following results for the dominant product channels: C4H4N (pyrrolyl) + HCN (BF = 0.61 ± 0.20), C3H3N2 (1H-imidazolyl/1H-pyrazolyl) + C2H2 (BF = 0.11 ± 0.06), and C5H4N2 (7-membered-ring molecules or pyrrole carbonitriles) + H (BF = 0.28 ± 0.10). The ring-contraction product channels C4H4N (pyrrolyl) + HCN, C3H3N2 (1H-imidazolyl) + C2H2, C3H3N2 (1H-pyrazolyl) + C2H2, and C5H5 (cyclopentadienyl) + N2 have statistical BFs of 0.54, 0.09, 0.11, and 0.07, respectively. Among the H-displacement channels, the cyclic-CHCHCHCHNCN + H channel and cyclic-CHCHCHCHCN2 + H are theoretically predicted to have a comparable BF (0.07 and 0.06, respectively), while the other isomeric 7-membered-ring molecule + H channel has a BF of 0.03. Pyrrole-carbonitriles and 1H-ethynyl-1H-imidazole (+ H) isomeric channels have an overall BF of 0.03. Implications for the chemistry of Saturn's moon Titan and prebiotic chemistry, as well as for understanding the N-doping of graphene or carbon nanotubes, are noted.
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Affiliation(s)
- Luca Mancini
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Adriana Caracciolo
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Noelia Faginas-Lago
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
- Master-Tec Srl, 06128 Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta" (CNR-SCITEC), 06123 Perugia, Italy
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), Istituto CNR di Scienze e Tecnologie Chimiche "Giulio Natta" (CNR-SCITEC), 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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2
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Schatz GC, Wodtke AM, Yang X. Spiers Memorial Lecture: New directions in molecular scattering. Faraday Discuss 2024; 251:9-62. [PMID: 38764350 DOI: 10.1039/d4fd00015c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2024]
Abstract
The field of molecular scattering is reviewed as it pertains to gas-gas as well as gas-surface chemical reaction dynamics. We emphasize the importance of collaboration of experiment and theory, from which new directions of research are being pursued on increasingly complex problems. We review both experimental and theoretical advances that provide the modern toolbox available to molecular-scattering studies. We distinguish between two classes of work. The first involves simple systems and uses experiment to validate theory so that from the validated theory, one may learn far more than could ever be measured in the laboratory. The second class involves problems of great complexity that would be difficult or impossible to understand without a partnership of experiment and theory. Key topics covered in this review include crossed-beams reactive scattering and scattering at extremely low energies, where quantum effects dominate. They also include scattering from surfaces, reactive scattering and kinetics at surfaces, and scattering work done at liquid surfaces. The review closes with thoughts on future promising directions of research.
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Affiliation(s)
- George C Schatz
- Dept of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
| | - Alec M Wodtke
- Institute for Physical Chemistry, Georg August University, Goettingen, Germany
- Max Planck Institute for Multidisciplinary Natural Sciences, Goettingen, Germany.
- International Center for the Advanced Studies of Energy Conversion, Georg August University, Goettingen, Germany
| | - Xueming Yang
- Dalian Institute for Chemical Physics, Chinese Academy of Sciences, Dalian, China
- Department of Chemistry, College of Science, Southern University of Science and Technology, Shenzhen, China
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3
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Yang Z, Medvedkov IA, Goettl SJ, Kaiser RI. Low-Temperature Gas-Phase Formation of Methanimine (CH 2NH; X 1A')─the Simplest Imine─under Single-Collision Conditions. J Phys Chem Lett 2023; 14:8500-8506. [PMID: 37721980 DOI: 10.1021/acs.jpclett.3c02360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
The D1-methanimine molecule (CHDNH; X1A')─the simplest (deuterated) imine─has been prepared through the elementary reaction of the D1-methylidyne (CD; X2Π) with ammonia (NH3; X1A1) under single collision conditions. As a highly reactive species with a carbon-nitrogen double bond and a key building block of biomolecules such as amino acids and nucleobases, methanimine is of particular significance in coupling the nitrogen and carbon chemistries in the interstellar medium and in hydrocarbon-rich atmospheres of planets and their moons. However, the underlying formation mechanisms of methanimine in these extreme environments are still elusive. The directed, low-temperature gas-phase formation of D1-methanimine will deepen our fundamental understanding of low-temperature molecular growth processes via carbon-nitrogen bond coupling. Considering the recent detection of the interstellar D1-methylidyne radical, the investigation of the CD-NH3 system also suggests a promising pathway for future astronomical observations of D1-methanimine as a molecular tracer of gas phase deuterium enrichment in deep space.
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Affiliation(s)
- Zhenghai Yang
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States
| | - Iakov A Medvedkov
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States
| | - Shane J Goettl
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, United States
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4
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Balucani N, Caracciolo A, Vanuzzo G, Skouteris D, Rosi M, Pacifici L, Casavecchia P, Hickson KM, Loison JC, Dobrijevic M. An experimental and theoretical investigation of the N( 2D) + C 6H 6 (benzene) reaction with implications for the photochemical models of Titan. Faraday Discuss 2023; 245:327-351. [PMID: 37293920 DOI: 10.1039/d3fd00057e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on a combined experimental and theoretical investigation of the N(2D) + C6H6 (benzene) reaction, which is of relevance in the aromatic chemistry of the atmosphere of Titan. Experimentally, the reaction was studied (i) under single-collision conditions by the crossed molecular beams (CMB) scattering method with mass spectrometric detection and time-of-flight analysis at the collision energy (Ec) of 31.8 kJ mol-1 to determine the primary products, their branching fractions (BFs), and the reaction micromechanism, and (ii) in a continuous supersonic flow reactor to determine the rate constant as a function of temperature from 50 K to 296 K. Theoretically, electronic structure calculations of the doublet C6H6N potential energy surface (PES) were performed to assist the interpretation of the experimental results and characterize the overall reaction mechanism. The reaction is found to proceed via barrierless addition of N(2D) to the aromatic ring of C6H6, followed by formation of several cyclic (five-, six-, and seven-membered ring) and linear isomeric C6H6N intermediates that can undergo unimolecular decomposition to bimolecular products. Statistical estimates of product BFs on the theoretical PES were carried out under the conditions of the CMB experiments and at the temperatures relevant for Titan's atmosphere. In all conditions the ring-contraction channel leading to C5H5 (cyclopentadienyl) + HCN is dominant, while minor contributions come from the channels leading to o-C6H5N (o-N-cycloheptatriene radical) + H, C4H4N (pyrrolyl) + C2H2 (acetylene), C5H5CN (cyano-cyclopentadiene) + H, and p-C6H5N + H. Rate constants (which are close to the gas kinetic limit at all temperatures, with the recommended value of 2.19 ± 0.30 × 10-10 cm3 s-1 over the 50-296 K range) and BFs have been used in a photochemical model of Titan's atmosphere to simulate the effect of the title reaction on the species abundances as a function of the altitude.
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Affiliation(s)
- Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Adriana Caracciolo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | | | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06100, Perugia, Italy
| | - Leonardo Pacifici
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Kevin M Hickson
- Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
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5
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Marco Tobías M, Åhlén M, Cheung O, Bucknall DG, McCoustra MRS, Yiu HHP. Plasma degradation of contaminated PPE: an energy-efficient method to treat contaminated plastic waste. NPJ MATERIALS DEGRADATION 2023; 7:33. [PMID: 37096160 PMCID: PMC10115383 DOI: 10.1038/s41529-023-00350-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 03/31/2023] [Indexed: 05/03/2023]
Abstract
The use of PPE has drastically increased because of the SARS-CoV-2 (COVID-19) pandemic as disposable surgical face masks made from non-biodegradable polypropylene (PP) polymers have generated a significant amount of waste. In this work, a low-power plasma method has been used to degrade surgical masks. Several analytical techniques (gravimetric analysis, scanning electron microscopy (SEM), attenuated total reflection-infra-red spectroscopy (ATR-IR), x-ray photoelectron spectroscopy (XPS), thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and wide-angle x-ray scattering (WAXS)) were used to evaluate the effects of plasma irradiation on mask samples. After 4 h of irradiation, an overall mass loss of 63 ± 8%, through oxidation followed by fragmentation, was observed on the non-woven 3-ply surgical mask, which is 20 times faster than degrading a bulk PP sample. Individual components of the mask also showed different degradation rates. Air plasma clearly represents an energy-efficient tool for treating contaminated PPE in an environmentally friendly approach.
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Affiliation(s)
- Mariano Marco Tobías
- Chemical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS UK
| | - Michelle Åhlén
- Nanotechnology and Functional Materials, Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
| | - Ocean Cheung
- Nanotechnology and Functional Materials, Department of Materials Science and Engineering, Uppsala University, Ångströmlaboratoriet, Lägerhyddsvägen 1, 752 37 Uppsala, Sweden
| | - David G. Bucknall
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS UK
| | - Martin R. S. McCoustra
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS UK
| | - Humphrey H. P. Yiu
- Chemical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS UK
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6
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Liang P, de Aragão EVF, Pannacci G, Vanuzzo G, Giustini A, Marchione D, Recio P, Ferlin F, Stranges D, Lago NF, Rosi M, Casavecchia P, Balucani N. Reactions O( 3P, 1D) + HCCCN(X 1Σ +) (Cyanoacetylene): Crossed-Beam and Theoretical Studies and Implications for the Chemistry of Extraterrestrial Environments. J Phys Chem A 2023; 127:685-703. [PMID: 36638186 PMCID: PMC9884085 DOI: 10.1021/acs.jpca.2c07708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cyanoacetylene (HCCCN), the first member of the cyanopolyyne family (HCnN, where n = 3, 5, 7, ...), is of particular interest in astrochemistry being ubiquitous in space (molecular clouds, solar-type protostars, protoplanetary disks, circumstellar envelopes, and external galaxies) and also relatively abundant. It is also abundant in the upper atmosphere of Titan and comets. Since oxygen is the third most abundant element in space, after hydrogen and helium, the reaction O + HCCCN can be of relevance in the chemistry of extraterrestrial environments. Despite that, scarce information exists not only on the reactions of oxygen atoms with cyanoacetylene but with nitriles in general. Here, we report on a combined experimental and theoretical investigation of the reactions of cyanoacetylene with both ground 3P and excited 1D atomic oxygen and provide detailed information on the primary reaction products, their branching fractions (BFs), and the overall reaction mechanisms. More specifically, the reactions of O(3P, 1D) with HCCCN(X1Σ+) have been investigated under single-collision conditions by the crossed molecular beams scattering method with mass spectrometric detection and time-of-flight analysis at the collision energy, Ec, of 31.1 kJ/mol. From product angular and time-of-flight distributions, we have identified the primary reaction products and determined their branching fractions (BFs). Theoretical calculations of the relevant triplet and singlet potential energy surfaces (PESs) were performed to assist the interpretation of the experimental results and clarify the reaction mechanism. Adiabatic statistical calculations of product BFs for the decomposition of the main triplet and singlet intermediates have also been carried out. Merging together the experimental and theoretical results, we conclude that the O(3P) reaction is characterized by a minor adiabatic channel leading to OCCCN (cyanoketyl) + H (experimental BF = 0.10 ± 0.05), while the dominant channel (BF = 0.90 ± 0.05) occurs via intersystem crossing to the underlying singlet PES and leads to formation of 1HCCN (cyanomethylene) + CO. The O(1D) reaction is characterized by the same two channels, with the relative CO/H yield being slightly larger. Considering the recorded reactive signal and the calculated entrance barrier, we estimate that the rate coefficient for reaction O(3P) + HC3N at 300 K is in the 10-12 cm3 molec-1 s-1 range. Our results are expected to be useful to improve astrochemical and photochemical models. In addition, they are also relevant in combustion chemistry, because the thermal decomposition of pyrrolic and pyridinic structures present in fuel-bound nitrogen generates many nitrogen-bearing compounds, including cyanoacetylene.
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Affiliation(s)
- Pengxiao Liang
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Emilia V. F. de Aragão
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy,Master-Tec
srl, Via Sicilia 41, Perugia 06128, Italy
| | - Giacomo Pannacci
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Gianmarco Vanuzzo
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Andrea Giustini
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Demian Marchione
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Pedro Recio
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Francesco Ferlin
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Domenico Stranges
- Dipartimento
di Chimica, Università degli Studi
La Sapienza, Roma 00185, Italy
| | - Noelia Faginas Lago
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Marzio Rosi
- Dipartimento
di Ingegneria Civile e Ambientale, Università
degli Studi di Perugia, Perugia 06123, Italy
| | - Piergiorgio Casavecchia
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy,E-mail:
| | - Nadia Balucani
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, Perugia 06123, Italy,E-mail:
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7
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Vanuzzo G, Mancini L, Pannacci G, Liang P, Marchione D, Recio P, Tan Y, Rosi M, Skouteris D, Casavecchia P, Balucani N, Hickson KM, Loison JC, Dobrijevic M. Reaction N( 2D) + CH 2CCH 2 (Allene): An Experimental and Theoretical Investigation and Implications for the Photochemical Models of Titan. ACS EARTH & SPACE CHEMISTRY 2022; 6:2305-2321. [PMID: 36303717 PMCID: PMC9589905 DOI: 10.1021/acsearthspacechem.2c00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
We report on a combined experimental and theoretical investigation of the N(2D) + CH2CCH2 (allene) reaction of relevance in the atmospheric chemistry of Titan. Experimentally, the reaction was investigated (i) under single-collision conditions by the crossed molecular beams (CMB) scattering method with mass spectrometric detection and time-of-flight analysis at the collision energy (E c) of 33 kJ/mol to determine the primary products and the reaction micromechanism and (ii) in a continuous supersonic flow reactor to determine the rate constant as a function of temperature from 50 to 296 K. Theoretically, electronic structure calculations of the doublet C3H4N potential energy surface (PES) were performed to assist the interpretation of the experimental results and characterize the overall reaction mechanism. The reaction is found to proceed via barrierless addition of N(2D) to one of the two equivalent carbon-carbon double bonds of CH2CCH2, followed by the formation of several cyclic and linear isomeric C3H4N intermediates that can undergo unimolecular decomposition to bimolecular products with elimination of H, CH3, HCN, HNC, and CN. The kinetic experiments confirm the barrierless nature of the reaction through the measurement of rate constants close to the gas-kinetic rate at all temperatures. Statistical estimates of product branching fractions (BFs) on the theoretical PES were carried out under the conditions of the CMB experiments at room temperature and at temperatures (94 and 175 K) relevant for Titan. Up to 14 competing product channels were statistically predicted with the main ones at E c = 33 kJ/mol being formation of cyclic-CH2C(N)CH + H (BF = 87.0%) followed by CHCCHNH + H (BF = 10.5%) and CH2CCNH + H (BF = 1.4%) the other 11 possible channels being negligible (BFs ranging from 0 to 0.5%). BFs under the other conditions are essentially unchanged. Experimental dynamical information could only be obtained on the overall H-displacement channel, while other possible channels could not be confirmed within the sensitivity of the method. This is also in line with theoretical predictions as the other possible channels are predicted to be negligible, including the HCN/HNC + C2H3 (vinyl) channels (overall BF < 1%). The dynamics and product distributions are dramatically different with respect to those observed in the isomeric reaction N(2D) + CH3CCH (propyne), where at a similar E c the main product channels are CH2NH (methanimine) + C2H (BF = 41%), c-C(N)CH + CH3 (BF = 32%), and CH2CHCN (vinyl cyanide) + H (BF = 12%). Rate coefficients (the recommended value is 1.7 (±0.2) × 10-10 cm3 s-1 over the 50-300 K range) and BFs have been used in a photochemical model of Titan's atmosphere to simulate the effect of the title reaction on the species abundance (including any new products formed) as a function of the altitude.
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Affiliation(s)
- Gianmarco Vanuzzo
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Luca Mancini
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Yuxin Tan
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento
di Ingegneria Civile e Ambientale, Università
degli Studi di Perugia, 06100 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Kevin M. Hickson
- Université
de Bordeaux, Institut des Sciences Moléculaires,
UMR 5255, F-33400 Talence, France
- CNRS,
Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France
| | - Jean-Christophe Loison
- Université
de Bordeaux, Institut des Sciences Moléculaires,
UMR 5255, F-33400 Talence, France
- CNRS,
Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France
| | - Michel Dobrijevic
- Laboratoire
d’Astrophysique de Bordeaux, Université
de Bordeaux, CNRS, B18N,
allée Geoffroy Saint-Hilaire, F-33615 Pessac, France
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8
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Vanuzzo G, Marchione D, Mancini L, Liang P, Pannacci G, Recio P, Tan Y, Rosi M, Skouteris D, Casavecchia P, Balucani N. The N( 2D) + CH 2CHCN (Vinyl Cyanide) Reaction: A Combined Crossed Molecular Beam and Theoretical Study and Implications for the Atmosphere of Titan. J Phys Chem A 2022; 126:6110-6123. [PMID: 36053010 PMCID: PMC9483977 DOI: 10.1021/acs.jpca.2c04263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The reaction of electronically excited nitrogen atoms,
N(2D), with vinyl cyanide, CH2CHCN, has been
investigated
under single-collision conditions by the crossed molecular beam (CMB)
scattering method with mass spectrometric detection and time-of-flight
(TOF) analysis at the collision energy, Ec, of 31.4 kJ/mol. Synergistic electronic structure calculations of
the doublet potential energy surface (PES) have been performed to
assist in the interpretation of the experimental results and characterize
the overall reaction micromechanism. Statistical (Rice–Ramsperger–Kassel–Marcus,
RRKM) calculations of product branching fractions (BFs) on the theoretical
PES have been carried out at different values of temperature, including
the one corresponding to the temperature (175 K) of Titan’s
stratosphere and at a total energy corresponding to the Ec of the CMB experiment. According to our theoretical
calculations, the reaction is found to proceed via barrierless addition
of N(2D) to the carbon–carbon double bond of CH2=CH–CN, followed by the formation of cyclic
and linear intermediates that can undergo H, CN, and HCN elimination.
In competition, the N(2D) addition to the CN group is also
possible via a submerged barrier, leading ultimately to N2 + C3H3 formation, the most exothermic of all
possible channels. Product angular and TOF distributions have been
recorded for the H-displacement channels leading to the formation
of a variety of possible C3H2N2 isomeric
products. Experimentally, no evidence of CN, HCN, and N2 forming channels was observed. These findings were corroborated
by the theory, which predicts a variety of competing product channels,
following N(2D) addition to the double bond, with the main
ones, at Ec = 31.4 kJ/mol, being six isomeric
H forming channels: c-CH(N)CHCN + H (BF = 35.0%), c-CHNCHCN + H (BF = 28.1%), CH2NCCN + H (BF =
26.3%), c-CH2(N)CCN(cyano-azirine) + H
(BF = 7.4%), trans-HNCCHCN + H (BF = 1.6%), and cis-HNCCHCN + H (BF = 1.3%), while C–C bond breaking
channels leading to c-CH2(N)CH(2H-azirine)
+ CN and c-CH2(N)C + HCN are predicted
to be negligible (0.02% and 0.2%, respectively). The highly exothermic
N2 + CH2CCH (propargyl) channel is also predicted
to be negligible because of the very high isomerization barrier from
the initial addition intermediate to the precursor intermediate able
to lead to products. The predicted product BFs are found to have,
in general, a very weak energy dependence. The above cyclic and linear
products containing an additional C–N bond could be potential
precursors of more complex, N-rich organic molecules that contribute
to the formation of the aerosols on Titan’s upper atmosphere.
Overall, the results are expected to have a significant impact on
the gas-phase chemistry of Titan’s atmosphere and should be
properly included in the photochemical models.
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Affiliation(s)
- Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Yuxin Tan
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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9
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He C, Fujioka K, Nikolayev AA, Zhao L, Doddipatla S, Azyazov VN, Mebel AM, Sun R, Kaiser RI. A chemical dynamics study of the reaction of the methylidyne radical (CH, X 2Π) with dimethylacetylene (CH 3CCCH 3, X 1A 1g). Phys Chem Chem Phys 2021; 24:578-593. [PMID: 34908056 DOI: 10.1039/d1cp04443e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The gas-phase reaction of the methylidyne (CH; X2Π) radical with dimethylacetylene (CH3CCCH3; X1A1g) was studied at a collision energy of 20.6 kJ mol-1 under single collision conditions with experimental results merged with ab initio calculations of the potential energy surface (PES) and ab initio molecule dynamics (AIMD) simulations. The crossed molecular beam experiment reveals that the reaction proceeds barrierless via indirect scattering dynamics through long-lived C5H7 reaction intermediate(s) ultimately dissociating to C5H6 isomers along with atomic hydrogen with atomic hydrogen predominantly released from the methyl groups as verified by replacing the methylidyne with the D1-methylidyne reactant. AIMD simulations reveal that the reaction dynamics are statistical leading predominantly to p28 (1-methyl-3-methylenecyclopropene, 13%) and p8 (1-penten-3-yne, 81%) plus atomic hydrogen with a significant amount of available energy being channeled into the internal excitation of the polyatomic reaction products. The dynamics are controlled by addition to the carbon-carbon triple bond with the reaction intermediates eventually eliminating a hydrogen atom from the methyl groups of the dimethylacetylene reactant forming 1-methyl-3-methylenecyclopropene (p28). The dominating pathways reveal an unexpected insertion of methylidyne into one of the six carbon-hydrogen single bonds of the methyl groups of dimethylacetylene leading to the acyclic intermediate, which then decomposes to 1-penten-3-yne (p8). Therefore, the methyl groups of dimethylacetylene effectively 'screen' the carbon-carbon triple bond from being attacked by addition thus directing the dynamics to an insertion process as seen exclusively in the reaction of methylidyne with ethane (C2H6) forming propylene (CH3C2H3). Therefore, driven by the screening of the triple bond, one propynyl moiety (CH3CC) acts in four out of five trajectories as a spectator thus driving an unexpected, but dominating chemistry in analogy to the methylidyne - ethane system.
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Affiliation(s)
- Chao He
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Kazuumi Fujioka
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Anatoliy A Nikolayev
- Lebedev Physical Institute, Samara 443011, Russia.,Samara National Research University, Samara 443086, Russia
| | - Long Zhao
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Valeriy N Azyazov
- Lebedev Physical Institute, Samara 443011, Russia.,Samara National Research University, Samara 443086, Russia
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA.
| | - Rui Sun
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
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10
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Mancini L, Vanuzzo G, Marchione D, Pannacci G, Liang P, Recio P, Rosi M, Skouteris D, Casavecchia P, Balucani N. The Reaction N( 2D) + CH 3CCH (Methylacetylene): A Combined Crossed Molecular Beams and Theoretical Investigation and Implications for the Atmosphere of Titan. J Phys Chem A 2021; 125:8846-8859. [PMID: 34609869 PMCID: PMC8521525 DOI: 10.1021/acs.jpca.1c06537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The reaction of excited
nitrogen atoms N(2D) with CH3CCH (methylacetylene)
was investigated under single-collision
conditions by the crossed molecular beams (CMB) scattering method
with mass spectrometric detection and time-of-flight analysis at the
collision energy (Ec) of 31.0 kJ/mol.
Synergistic electronic structure calculations of the doublet potential
energy surface (PES) were performed to assist the interpretation of
the experimental results and characterize the overall reaction micromechanism.
Theoretically, the reaction is found to proceed via a barrierless addition of N(2D) to the carbon–carbon
triple bond of CH3CCH and an insertion of N(2D) into the CH bond of the methyl group, followed
by the formation of cyclic and linear intermediates that can undergo
H, CH3, and C2H elimination or isomerize to
other intermediates before unimolecularly decaying to a variety of
products. Kinetic calculations for addition and insertion mechanisms
and statistical (Rice-Ramsperger-Kassel-Marcus) computations of product
branching fractions (BFs) on the theoretical PES were performed at
different values of total energy, including the one corresponding
to the temperature (175 K) of Titan’s stratosphere and that
of the CMB experiment. Up to 14 competing product channels were statistically
predicted, with the main ones, at Ec =
31.0 kJ/mol, being the formation of CH2NH (methanimine)
+ C2H (ethylidyne) (BF = 0.41), c-C(N)CH
+ CH3 (BF = 0.32), CH2CHCN (acrylonitrile) +
H (BF = 0.12), and c-CH2C(N)CH + H (BF
= 0.04). Of the 14 possible channels, seven correspond to H displacement
channels of different exothermicity, for a total H channel BF of ∼0.25
at Ec = 31.0 kJ/mol. Experimentally, dynamical
information could only be obtained about the overall H channels. In
particular, the experiment corroborates the formation of acrylonitrile
+ H, which is the most exothermic of all 14 reaction channels and
is theoretically calculated to be the dominant H-forming channel (BF
= 0.12). The products containing a novel C–N bond could be
potential precursors to form other nitriles (C2N2, C3N) or more complex organic species containing N atoms
in planetary atmospheres, such as those of Titan and Pluto. Overall,
the results are expected to have a potentially significant impact
on the understanding of the gas-phase chemistry of Titan’s
atmosphere and the modeling of that atmosphere.
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Affiliation(s)
- Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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11
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Recio P, Marchione D, Caracciolo A, Murray VJ, Mancini L, Rosi M, Casavecchia P, Balucani N. A crossed molecular beam investigation of the N(2D) + pyridine reaction and implications for prebiotic chemistry. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Liang P, Mancini L, Marchione D, Vanuzzo G, Ferlin F, Recio P, Tan Y, Pannacci G, Vaccaro L, Rosi M, Casavecchia P, Balucani N. Combined crossed molecular beams and computational study on the N( 2D) + HCCCN(X 1Σ +) reaction and implications for extra-terrestrial environments. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1948126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Francesco Ferlin
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Yuxin Tan
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
- ERASMUS+ Visiting Ph.D. student from Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Luigi Vaccaro
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, Perugia, Italy
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
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13
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Chin CH, Zhu T, Zhang JZH. Cyclopentadienyl radical formation from the reaction of excited nitrogen atoms with benzene: a theoretical study. Phys Chem Chem Phys 2021; 23:12408-12420. [PMID: 34027937 DOI: 10.1039/d1cp00133g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ab initio CCSD(T)/CBS//ωB97X-D/6-311+G(d,p) calculations of the C6H6N potential energy surface were performed to investigate the reaction mechanism underlying the reaction of atomic nitrogen (2D) with benzene. Thereafter, Rice-Ramsperger-Kassel-Marcus (RRKM) calculations of reaction rate constants and product branching ratios were performed under single-collision conditions. The results revealed that the N(2D) + C6H6 reaction in the case of statistical behavior is expected to produce hydrogen cyanide plus a cyclopentadienyl radical (91.5-88.9%), acetylene plus a pyrrole radical (5.8-7.5%), 1-cyano-2,4-cyclopentadiene + H (2.3-3.0%) and 1-ethynyl-pyrrole + H (0.4-0.6%), with the most favorable pathways being the initial adduct i1 leading to the formation of a seven-membered cyclic intermediate i12 through an exothermic ring expansion process and a multistep route i12 → i15 → i16 → C5H5 + HCN featuring an intramolecular ring-shrinking process involving a C-C bond fusion elimination channel to yield the bicyclic intermediate i15, followed by hydrogen cyanide elimination, thus forming a cyclopentadienyl radical. The calculated product branching ratios were consistent with the available experimental data; however, some quantitative deviations from the experimental results and the possible reasons are also discussed. The possible effects of the title reaction on the upper atmosphere of Titan, with critical implications for the rapid degradation of nitrogen-bearing polycyclic aromatic hydrocarbons, were compared with the mass growth processes of their polycyclic aromatic hydrocarbon counterparts produced through ring expansion.
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Affiliation(s)
- Chih-Hao Chin
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China.
| | - Tong Zhu
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China.
| | - John Zeng Hui Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China. and Department of Chemistry, New York University, New York 10003, USA
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14
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Sun F, Xie M, Zhang Y, Song W, Sun X, Hu Y. Spectroscopic evidence of the C-N covalent bond formed between two interstellar molecules (ISM): acrylonitrile and ammonia. Phys Chem Chem Phys 2021; 23:9672-9678. [PMID: 33616131 DOI: 10.1039/d0cp06274j] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acrylonitrile (AN) and ammonia (NH3) are two important nitrogen-containing interstellar molecules in outer space, especially on Titan. Herein, we measured infrared (IR) spectra of neutral and cationic AN-NH3 complexes by VUV single-photon ionization combined with time-of-flight mass spectrometry. On combining IR spectra with the theoretical calculations, we found that the molecules prefer to form a single-ring cyclic H-bonded structure in the neutral AN-NH3 and (AN)2-NH3 clusters. However, after ionization of AN-NH3 and (AN)2-NH3 clusters, a new C-N-covalent bond is confirmed to form directly between AN and NH3, without any energy barrier in the cationic complexes. Moreover, in the ionized (AN)2-NH3 cluster, the covalent C-N bond prefers to form between AN and NH3 rather than the two AN groups. These results provide spectroscopic evidence of AN forming a new molecule with NH3, induced by VUV radiation. The formation of the new C-N bond broadens our knowledge on the evolution of the prebiotic nitrogen-containing molecules in space.
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Affiliation(s)
- Fufei Sun
- MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
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15
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Falcinelli S, Rosi M. Production and Characterization of Molecular Dications: Experimental and Theoretical Efforts. Molecules 2020; 25:molecules25184157. [PMID: 32932839 PMCID: PMC7571021 DOI: 10.3390/molecules25184157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/08/2020] [Accepted: 09/09/2020] [Indexed: 11/16/2022] Open
Abstract
Molecular dications are doubly charged cations of importance in flames, plasma chemistry and physics and in the chemistry of the upper atmosphere of Planets. Furthermore, they are exotic species able to store a considerable amount of energy at a molecular level. This high energy content of several eV can be easily released as translational energy of the two fragment monocations generated by their Coulomb explosion. For such a reason, they were proposed as a new kind of alternative propellant. The present topic review paper reports on an overview of the main contributions made by the authors’ research groups in the generation and characterization of simple molecular dications during the last 40 years of coupling experimental and theoretical efforts.
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Affiliation(s)
- Stefano Falcinelli
- Department of Civil and Environmental Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia, Italy
- Correspondence: (S.F.); (M.R.); Tel.: +39-075-585-3862 (S.F.); +39-075-585-3858 (M.R.)
| | - Marzio Rosi
- Department of Civil and Environmental Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia, Italy
- SCITEC, CNR, Via Elce di Sotto 8, 06123 Perugia, Italy
- Correspondence: (S.F.); (M.R.); Tel.: +39-075-585-3862 (S.F.); +39-075-585-3858 (M.R.)
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16
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Zareipour R, Vahedpour M. Ground state potential energy surface of methanimine plus 3NH reaction: Rates of atmospheric reactions and validated mechanisms. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.112799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Tachikawa H. Intramolecular Reactions in Ionized Ammonia Clusters: A Direct Ab Initio Molecular Dynamics Study. J Phys Chem A 2020; 124:1903-1910. [PMID: 32049527 DOI: 10.1021/acs.jpca.9b11122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ammonia cluster cations are a chemical species that has recently attracted considerable research attention as an ion-molecule reaction species in the planetary atmosphere, surface reaction species in materials chemistry, and super-alkali species. Reactions of the radical cation of an ammonia cluster, [(NH3)n]+ (n = 2-6), following the ionization of the parent neutral cluster, were investigated using direct ab initio molecular dynamics to elucidate the reactions of the ammonia cluster cation under astrochemical conditions. The calculations showed that two competing reaction channels-proton transfer (PT) channel and complex formation channel-operate after the ionization of neutral clusters. In the PT channel, a proton of NH3+ was transferred to a neighboring ammonia molecule. The PT channel was found in all clusters (n = 2-6). Reaction via the PT channel became faster with increasing cluster size and saturated around n = 5-6. In the complex formation channel, a face-to-face complex having a H3N-NH3+ structure (with a N-N bond) was formed. This channel was found only in larger clusters (n = 5-6). Time scales of PT and complex formation channels were calculated to be 20-30 and 40-50 fs, respectively. The reaction mechanism was discussed based on the results of theoretical calculations.
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Affiliation(s)
- Hiroto Tachikawa
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
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18
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Li Y, Song W, Jiang N, Zhang Z, Xie M, Hu Y. Structural rearrangement of the acrylonitrile (AN) cluster in the gas phase under VUV one-photon radiation explored by mass-selected infrared spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 226:117620. [PMID: 31610467 DOI: 10.1016/j.saa.2019.117620] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/27/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
Acrylonitrile (AN), one of the most abundant nitriles in space, is considered to closely relate to the formation of interstellar prebiotic nitrogen-containing aromatics. Herein, we measured the vibrational spectra of acrylonitrile cluster cations (AN)2,3+ in a supersonic jet using infrared (IR) dissociation with vacuum-ultraviolet (VUV) photoionization and time-of-flight mass spectroscopy. Interestingly, the observed IR spectra demonstrate that a new molecular ion [Formula: see text] , is generated from the dimer and trimer of AN upon VUV single-photo ionization. Calculation results reveal that the new molecular cations can be generated through a relative low energy barrier after ionization of the neutral (AN)2. However, the reaction pathways are barrierless for the trimer, in which the third solvent AN acts as a catalyst. The mechanisms of those reactions also have been discussed in detail. This study contributes to a deeper understanding of ion-molecule reaction in gas-phase and the quest for the formation of prebiotic N -containing molecules in the outer space.
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Affiliation(s)
- Yujian Li
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Wentao Song
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Ningjing Jiang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Zhaoli Zhang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China
| | - Min Xie
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China.
| | - Yongjun Hu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, South China Normal University, Guangzhou, 510631, PR China.
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19
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Li H, Suits AG. Universal crossed beam imaging studies of polyatomic reaction dynamics. Phys Chem Chem Phys 2020; 22:11126-11138. [DOI: 10.1039/d0cp00522c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crossed-beam imaging studies of polyatomic reactions show surprising dynamics not anticipated by extrapolation from smaller model systems.
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Affiliation(s)
- Hongwei Li
- Department of Chemistry
- University of Missouri
- Columbia
- USA
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20
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Ayari T, Desouter-Lecomte M, Linguerri R, Garcia GA, Nahon L, Ben Houria A, Ghalila H, Ben Said R, Hochlaf M. State-to-state dissociative photoionization of molecular nitrogen: the full story. ADVANCES IN PHYSICS: X 2020. [DOI: 10.1080/23746149.2020.1831955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- T. Ayari
- COSYS/LISIS, Université Gustave Eiffel, Champs-sur-Marne, France
- Laboratoire De Spectroscopie Atomique, Moléculaire Et Applications – LSAMA, Université De Tunis El Manar, Tunis, Tunisia
| | - M. Desouter-Lecomte
- Institut De Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, Orsay, France
| | - R. Linguerri
- COSYS/LISIS, Université Gustave Eiffel, Champs-sur-Marne, France
| | - G. A. Garcia
- Synchrotron SOLEIL, L’orme Des Merisiers, Saint-Aubin, Gif-sur-Yvette Cedex, France
| | - L. Nahon
- Synchrotron SOLEIL, L’orme Des Merisiers, Saint-Aubin, Gif-sur-Yvette Cedex, France
| | - A. Ben Houria
- Laboratoire De Spectroscopie Atomique, Moléculaire Et Applications – LSAMA, Université De Tunis El Manar, Tunis, Tunisia
| | - H. Ghalila
- Laboratoire De Spectroscopie Atomique, Moléculaire Et Applications – LSAMA, Université De Tunis El Manar, Tunis, Tunisia
| | - R. Ben Said
- Department of Chemistry, College of Science and Arts, Qassim University, Ar Rass, Saudi Arabia
| | - M. Hochlaf
- COSYS/LISIS, Université Gustave Eiffel, Champs-sur-Marne, France
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21
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Chang YC, Liu K, Kalogerakis KS, Ng CY, Jackson WM. Branching Ratios of the N( 2D 03/2) and N( 2D 05/2) Spin-Orbit States Produced in the State-Selected Photodissociation of N 2 Determined Using Time-Sliced Velocity-Mapped-Imaging Photoionization Mass Spectrometry (TS-VMI-PI-MS). J Phys Chem A 2019; 123:2289-2300. [PMID: 30628443 DOI: 10.1021/acs.jpca.8b11691] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Branching ratios for N(2D03/2) and N(2D05/2) produced by predissociation of state selected excited nitrogen molecules in the vacuum ultraviolet region have been measured for the first time. The quantum numbers of the excited nitrogen molecule are defined by selective excitation of the nitrogen molecule in the Franck-Condon region from the ground electronic, 1Σg+, vibrational, v″, and rotational, J″ state to an excited Eu', v', J' state with a tunable vacuum ultraviolet, VUV1, laser. The neutral atoms produced by predissociation from this excited state are then selectively ionized with a second tunable VUV2 laser. Measurement of the relative populations of these two atoms formed in their spin-orbit states defines the quantum states for the atomic products. This means that the wave functions of the initial state and knowledge of the relative yields define all the experimental parameters for this series of unimolecular reactions. The ions formed by VUV2 are mass analyzed with a time-of-flight mass spectrometer and detected with a time slice velocity ion imaging mass spectrometer. In this manner, we can determine the recoil velocity associated with the predissociation process. Two different techniques are used to determine the spin-orbit ratios, namely, resonant VUV photoionization (RVUV-PI) spectroscopy and total kinetic energy release (TKER) spectroscopy determined from the image produced when the atoms are selectively ionized by VUV2 in the interaction region. The TKER spectra obtained from the lines at 110 296.25 and 110 304.96 cm-1 that couple to a newly discovered autoionization line at 129 529.4255 ± 0.0015 cm-1 prove that the lines observed in this region originate from the N(2D03/2) and N(2D05/2) atoms. Two other lines in this region at 110 286.20 and 110 299.89 cm-1 originate from the nitrogen N(4S03/2) that is photoionized in a 1+ 1 VUV-UV resonant multiphoton ionization process. The spin-orbit branching ratios have been evaluated for valence and Rydberg electronic excited states from 104 129.4 to 118 772.1 cm-1, and it shows that they are independent of the rotational and vibrational quantum numbers. They are not appreciably affected by the symmetry properties of the wave function in the Franck-Condon region of the excited states. In the energy region below 117 153.8 cm-1 the pathways at long internuclear distances appear to determine [N(2D03/2)]/[N(2D05/2)] branching ratios of ∼0.38, ∼0.62, and ∼1.04. At higher energies, TKER and RVUV-PI spectroscopy have been used to show that the average fraction of the N(2D03/2) and N(2D05/2) atoms produced in the spin-allowed channels that produce two N(2D0J) is 0.85 versus 0.15 for spin-forbidden channels. The importance and need for this information for comparison with theory and applications in astrochemistry are briefly discussed.
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Affiliation(s)
- Yih Chung Chang
- Department of Chemistry , University of California , Davis , California 95616 , United States
| | - Kai Liu
- Wuhan Institute of Physics and Mathematics, CAS , Wuhan 430071 , China
| | | | - Cheuk-Yiu Ng
- Department of Chemistry , University of California , Davis , California 95616 , United States
| | - William M Jackson
- Department of Chemistry , University of California , Davis , California 95616 , United States
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Rivilla VM, Martín-Pintado J, Jiménez-Serra I, Zeng S, Martín S, Armijos-Abendaño J, Requena-Torres MA, Aladro R, Riquelme D. Abundant Z-cyanomethanimine in the interstellar medium: paving the way to the synthesis of adenine. ACTA ACUST UNITED AC 2018. [DOI: 10.1093/mnrasl/sly228] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- V M Rivilla
- INAF-Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125, Florence, Italy
| | - J Martín-Pintado
- Centro de Astrobiología (CSIC−INTA). Ctra de Ajalvir, km. 4, Torrejón de Ardoz, E-28850 Madrid, Spain
| | - I Jiménez-Serra
- Centro de Astrobiología (CSIC−INTA). Ctra de Ajalvir, km. 4, Torrejón de Ardoz, E-28850 Madrid, Spain
| | - S Zeng
- School of Physics and Astronomy, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
| | - S Martín
- European Southern Observatory (ESO), Alonso de Córdova 3107, Vitacura, 763 0355 Santiago, Chile
- Joint ALMA Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile
| | - J Armijos-Abendaño
- Observatorio Astronómico de Quito, Escuela Politécnica Nacional, Av. Gran Colombia S/N, Interior del Parque La Alameda, 170136 Quito, Ecuador
| | - M A Requena-Torres
- Department of Astronomy, University of Maryland, College Park, ND 20742-2421, USA
| | - R Aladro
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
| | - D Riquelme
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
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Vazart F, Latouche C, Cimino P, Barone V. Accurate Infrared (IR) Spectra for Molecules Containing the C≡N Moiety by Anharmonic Computations with the Double Hybrid B2PLYP Density Functional. J Chem Theory Comput 2015; 11:4364-9. [PMID: 26575929 DOI: 10.1021/acs.jctc.5b00638] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein, we report a comprehensive benchmark of C≡N stretching vibrations computed at harmonic and anharmonic levels with the aim of proposing and validating a reliable computational strategy to get accurate results for this puzzling vibrational mode without any ad hoc scaling factor. Anharmonic calculations employing second-order vibrational perturbation theory provide very good results when performed using the B2PLYP double-hybrid functional, in conjunction with an extended basis set and supplemented by semiempirical dispersion contributions. For larger systems, B2PLYP harmonic frequencies, together with B3LYP anharmonic corrections, offer a very good compromise between accuracy and computational cost without the need of any empirical scaling factor.
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Affiliation(s)
- Fanny Vazart
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Camille Latouche
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Paola Cimino
- Dipartimento di Farmacia (DIFARMA), Università di Salerno , via Giovanni Paolo II, 132, 84084 Fisciano (SA), Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
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Vazart F, Latouche C, Skouteris D, Balucani N, Barone V. CYANOMETHANIMINE ISOMERS IN COLD INTERSTELLAR CLOUDS: INSIGHTS FROM ELECTRONIC STRUCTURE AND KINETIC CALCULATIONS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/810/2/111] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Vazart F, Calderini D, Skouteris D, Latouche C, Barone V. Reassessment of the Thermodynamic, Kinetic, and Spectroscopic Features of Cyanomethanimine Derivatives: A Full Anharmonic Perturbative Treatment. J Chem Theory Comput 2015; 11:1165-71. [PMID: 26579765 DOI: 10.1021/ct501147a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein we report a full thermodynamic and vibrational investigation of C-cyanomethanimine isomers rooted into the Density Functional Theory (DFT) and the second-order vibrational perturbation theory (VPT2). We show that an anharmonic treatment affects dramatically the vibrational behavior of the molecules, especially thanks to the inclusion of interaction terms between the various modes. Furthermore, the equilibrium constant between the isomers, as well as the rate constant, have been obtained at both harmonic and anharmonic levels showing, as expected, slight but non-negligible differences. To support our investigation, dispersion effects have been employed.
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Affiliation(s)
- Fanny Vazart
- Scuola Normale Superiore , piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Danilo Calderini
- Scuola Normale Superiore , piazza dei Cavalieri 7, 56125 Pisa, Italy
| | | | - Camille Latouche
- Scuola Normale Superiore , piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore , piazza dei Cavalieri 7, 56125 Pisa, Italy
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Hamid AM, Bera PP, Lee TJ, Aziz SG, Alyoubi AO, El-Shall MS. Evidence for the Formation of Pyrimidine Cations from the Sequential Reactions of Hydrogen Cyanide with the Acetylene Radical Cation. J Phys Chem Lett 2014; 5:3392-3398. [PMID: 26278451 DOI: 10.1021/jz501648q] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Herein, we report the first direct evidence for the formation of pyrimidine ion isomers by sequential reactions of HCN with the acetylene radical cation in the gas phase at ambient temperature using the mass-selected variable temperature and pressure ion mobility technique. The formation and structures of the pyrimidine ion isomers are theoretically predicted via coupled cluster and density functional theory calculations. This ion-molecule synthesis may indicate that pyrimidine is produced in the gas phase in space environments before being incorporated into condensed-phase ices and transformed into nucleic acid bases such as uracil.
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Affiliation(s)
- Ahmed M Hamid
- †Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
| | - Partha P Bera
- ‡NASA Ames Research Center, Moffett Field, California 94035, United States
- #Bay Area Environmental Research Institute, Petaluma, California 94952, United States
| | - Timothy J Lee
- ‡NASA Ames Research Center, Moffett Field, California 94035, United States
| | - Saadullah G Aziz
- §Department of Chemistry, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | | | - M Samy El-Shall
- †Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006, United States
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Attah IK, Platt SP, Meot-Ner (Mautner) M, El-Shall MS, Aziz SG, Alyoubi AO. Proton-bound dimers of nitrogen heterocyclic molecules: Substituent effects on the structures and binding energies of homodimers of diazine, triazine, and fluoropyridine. J Chem Phys 2014; 140:114313. [DOI: 10.1063/1.4867288] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Peng Z, Carrasco N, Pernot P. Modeling of synchrotron-based laboratory simulations of Titan’s ionospheric photochemistry. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.grj.2014.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Production of ions at high energy and its role in extraterrestrial environments. RENDICONTI LINCEI-SCIENZE FISICHE E NATURALI 2012. [DOI: 10.1007/s12210-012-0215-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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Balucani N, Skouteris D, Leonori F, Petrucci R, Hamberg M, Geppert WD, Casavecchia P, Rosi M. Combined crossed beam and theoretical studies of the N(2D) + C2H4 reaction and implications for atmospheric models of Titan. J Phys Chem A 2012; 116:10467-79. [PMID: 23016665 DOI: 10.1021/jp3072316] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamics of the H displacement channels in the reaction N((2)D) + C(2)H(4) have been investigated by the crossed molecular beam technique with mass spectrometric detection and time-of-flight analysis at two different collision energies (17.2 and 28.2 kJ/mol). The interpretation of the scattering results is assisted by new electronic structure calculations of stationary points and product energetics for the C(2)H(4)N ground state doublet potential energy surface. RRKM statistical calculations have been performed to derive the product branching ratio under the conditions of the present experiments and of the atmosphere of Titan. Similarities and differences with respect to a recent study performed in crossed beam experiments coupled to ionization via tunable VUV synchrotron radiation are discussed (Lee, S.-H.; et al. Phys. Chem. Chem. Phys.2011, 13, 8515-8525). Implications for the atmospheric chemistry of Titan are presented.
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Affiliation(s)
- Nadia Balucani
- Dipartimento di Chimica, Università degli Studi di Perugia, 06123 Perugia, Italy.
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Ptasinska S, Tolbatov I, Bartl P, Yurkovich J, Coffey B, Chipman DM, Leidlmair C, Schöbel H, Scheier P, Mason NJ. Electron impact on N2/CH4 mixtures in He droplets—probing chemistry in Titan's atmosphere. RSC Adv 2012. [DOI: 10.1039/c2ra21444j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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