1
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Lang J, Foley CD, Thawoos S, Behzadfar A, Liu Y, Zádor J, Suits AG. Reaction dynamics of S( 3P) with 1,3-butadiene and isoprene: crossed-beam scattering, low-temperature flow experiments, and high-level electronic structure calculations. Faraday Discuss 2024. [PMID: 38807494 DOI: 10.1039/d4fd00009a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Sulfur atoms serve as key players in diverse chemical processes, from astrochemistry at very low temperature to combustion at high temperature. Building upon our prior findings, showing cyclization to thiophenes following the reaction of ground-state sulfur atoms with dienes, we here extend this investigation to include many additional reaction products, guided by detailed theoretical predictions. The outcomes highlight the complex formation of products during intersystem crossing (ISC) to the singlet surfaces. Here, we employed crossed-beam velocity map imaging and high-level ab initio methods to explore the reaction of S(3P) with 1,3-butadiene and isoprene under single-collision conditions and in low-temperature flows. For the butadiene reaction, our experimental results show the formation of thiophene via H2 loss, a 2H-thiophenyl radical through H loss, and thioketene through ethene loss at a slightly higher collision energy compared to previous observations. Complementary Chirped-Pulse Fourier-Transform mmWave spectroscopy (CP-FTmmW) measurements in a uniform flow confirmed the formation of thioketene in the reaction at 20 K. For the isoprene reaction, we observed analogous products along with the 2H-thiophenyl radical arising from methyl loss and C3H4S (loss of ethene or H2 + acetylene). CP-FTmmW detected the formation of thioformaldehyde via loss of 1,3-butadiene, again in the 20 K flow. Coupled-cluster calculations on the pathways found by the automated kinetic workflow code KinBot support these findings and indicate ISC to the singlet surface, leading to the generation of various long-lived intermediates, including 5-membered heterocycles.
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Affiliation(s)
- Jinxin Lang
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
| | - Casey D Foley
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
| | - Shameemah Thawoos
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
| | - Abbas Behzadfar
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
| | - Yanan Liu
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
| | - Judit Zádor
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
| | - Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
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2
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Guillaume T, Hays BM, Gupta D, Cooke IR, Abdelkader Khedaoui O, Hearne TS, Drissi M, Sims IR. Product-specific reaction kinetics in continuous uniform supersonic flows probed by chirped-pulse microwave spectroscopy. J Chem Phys 2024; 160:204201. [PMID: 38808747 DOI: 10.1063/5.0203428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 05/06/2024] [Indexed: 05/30/2024] Open
Abstract
Experimental studies of the products of elementary gas-phase chemical reactions occurring at low temperatures (<50 K) are very scarce, but of importance for fundamental studies of reaction dynamics, comparisons with high-level quantum dynamical calculations, and, in particular, for providing data for the modeling of cold astrophysical environments, such as dense interstellar clouds, the atmospheres of the outer planets, and cometary comae. This study describes the construction and testing of a new apparatus designed to measure product branching fractions of elementary bimolecular gas-phase reactions at low temperatures. It combines chirped-pulse Fourier transform millimeter wave spectroscopy with continuous uniform supersonic flows and high repetition rate laser photolysis. After a comprehensive description of the apparatus, the experimental procedures and data processing protocols used for signal recovery, the capabilities of the instrument are explored by the study of the photodissociation of acrylonitrile and the detection of two of its photoproducts, HC3N and HCN. A description is then given of a study of the reactions of the CN radical with C2H2 at 30 K, detecting the HC3N product, and with C2H6 at 10 K, detecting the HCN product. A calibration of these two products is finally attempted using the photodissociation of acrylonitrile as a reference process. The limitations and possible improvements in the instrument are discussed in conclusion.
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Affiliation(s)
| | | | | | | | | | | | | | - Ian R Sims
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
- Institut universitaire de France (IUF), France
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3
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Dias N, Gurusinghe RM, Suits AG. Multichannel Radical-Radical Reaction Dynamics of NO + Propargyl Probed by Broadband Rotational Spectroscopy. J Phys Chem A 2022; 126:5354-5362. [PMID: 35938878 DOI: 10.1021/acs.jpca.2c01629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chirped-pulse rotational spectroscopy in a quasi-uniform flow has been used to investigate the reaction dynamics of a multichannel radical-radical reaction of relevance to planetary atmospheres and combustion. In this work, the NO + propargyl (C3H3) reaction was found to yield six product channels containing eight detected species. These products and their branching fractions (%), are as follows: HCN (50), HCNO (18), CH2CN (12), CH3CN (7.4), HC3N (6.2), HNC (2.3), CH2CO (1.3), HCO (1.8). The results are discussed in light of previous unimolecular photodissociation studies of isoxazole and prior potential energy surface calculations of the NO + C3H3 system. The results also show that the product branching is strongly influenced by the excess energy of the reactant radicals. The implications of the title reaction to the planetary atmospheres, particularly to Titan, are discussed.
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Affiliation(s)
- Nureshan Dias
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211 United States
| | - Ranil M Gurusinghe
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211 United States
| | - Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211 United States
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4
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Wu LY, Miossec C, Heazlewood BR. Low-temperature reaction dynamics of paramagnetic species in the gas phase. Chem Commun (Camb) 2022; 58:3240-3254. [PMID: 35188499 PMCID: PMC8902758 DOI: 10.1039/d1cc06394d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/12/2022] [Indexed: 12/12/2022]
Abstract
Radicals are abundant in a range of important gas-phase environments. They are prevalent in the atmosphere, in interstellar space, and in combustion processes. As such, understanding how radicals react is essential for the development of accurate models of the complex chemistry occurring in these gas-phase environments. By controlling the properties of the colliding reactants, we can also gain insights into how radical reactions occur on a fundamental level. Recent years have seen remarkable advances in the breadth of experimental methods successfully applied to the study of reaction dynamics involving paramagnetic species-from improvements to the well-known crossed molecular beams approach to newer techniques involving magnetically guided and decelerated beams. Coupled with ever-improving theoretical methods, quantum features are being observed and interesting insights into reaction dynamics are being uncovered in an increasingly diverse range of systems. In this highlight article, we explore some of the exciting recent developments in the study of chemical dynamics involving paramagnetic species. We focus on low-energy reactive collisions involving neutral radical species, where the reaction parameters are controlled. We conclude by identifying some of the limitations of current methods and exploring possible new directions for the field.
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Affiliation(s)
- Lok Yiu Wu
- The Oliver Lodge, Department of Physics, University of Liverpool, Oxford Street, Liverpool, L69 7ZE, UK.
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Chloé Miossec
- The Oliver Lodge, Department of Physics, University of Liverpool, Oxford Street, Liverpool, L69 7ZE, UK.
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
| | - Brianna R Heazlewood
- The Oliver Lodge, Department of Physics, University of Liverpool, Oxford Street, Liverpool, L69 7ZE, UK.
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5
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Gurusinghe RM, Dias N, Krueger R, Suits AG. Uniform supersonic flow sampling for detection by chirped-pulse rotational spectroscopy. J Chem Phys 2022; 156:014202. [PMID: 34998338 DOI: 10.1063/5.0073527] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy is a powerful near-universal detection method finding application in many areas. We have previously coupled it with supersonic flows (CPUF) to obtain product branching in reaction and photodissociation. Because chirped-pulse microwave detection requires monitoring the free induction decay on the timescale of microseconds, it cannot be employed with good sensitivity at the high densities achieved in some uniform supersonic flows. For application to low-temperature kinetics studies, a truly uniform flow is required to obtain reliable rate measurements and enjoy all the advantages that CP-FTMW has to offer. To this end, we present a new setup that combines sampling of uniform supersonic flows using an airfoil-shaped sampling device with chirped-pulse mmW detection. Density and temperature variations in the airfoil-sampled uniform flow were revealed using time-dependent rotational spectroscopy of pyridine and vinyl cyanide photoproducts, highlighting the use of UV photodissociation as a sensitive diagnostic tool for uniform flows. The performance of the new airfoil-equipped CPUF rotational spectrometer was validated using kinetics measurements of the CN + C2H6 reaction at 50 K with detection of the HCN product. Issues relating to product detection by rotational spectroscopy and airfoil sampling are discussed. We show that airfoil sampling enables direct measurements of low temperature reaction kinetics on a microsecond timescale, while rotational spectroscopic detection enables highly specific simultaneous detection of reactants and products.
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Affiliation(s)
- Ranil M Gurusinghe
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | - Nureshan Dias
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | - Ritter Krueger
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | - Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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6
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Fulvio D, Potapov A, He J, Henning T. Astrochemical Pathways to Complex Organic and Prebiotic Molecules: Experimental Perspectives for In Situ Solid-State Studies. Life (Basel) 2021; 11:life11060568. [PMID: 34204233 PMCID: PMC8235774 DOI: 10.3390/life11060568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 02/05/2023] Open
Abstract
A deep understanding of the origin of life requires the physical, chemical, and biological study of prebiotic systems and the comprehension of the mechanisms underlying their evolutionary steps. In this context, great attention is paid to the class of interstellar molecules known as "Complex Organic Molecules" (COMs), considered as possible precursors of prebiotic species. Although COMs have already been detected in different astrophysical environments (such as interstellar clouds, protostars, and protoplanetary disks) and in comets, the physical-chemical mechanisms underlying their formation are not yet fully understood. In this framework, a unique contribution comes from laboratory experiments specifically designed to mimic the conditions found in space. We present a review of experimental studies on the formation and evolution of COMs in the solid state, i.e., within ices of astrophysical interest, devoting special attention to the in situ detection and analysis techniques commonly used in laboratory astrochemistry. We discuss their main strengths and weaknesses and provide a perspective view on novel techniques, which may help in overcoming the current experimental challenges.
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Affiliation(s)
- Daniele Fulvio
- Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, 80131 Naples, Italy
- Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany; (J.H.); (T.H.)
- Correspondence:
| | - Alexey Potapov
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, 07743 Jena, Germany;
| | - Jiao He
- Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany; (J.H.); (T.H.)
| | - Thomas Henning
- Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany; (J.H.); (T.H.)
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7
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Marcelino N, Tercero B, Agúndez M, Cernicharo J. A study of C 4H 3N isomers in TMC-1: line by line detection of HCCCH 2CN. ASTRONOMY AND ASTROPHYSICS 2021; 646:L9. [PMID: 33828332 PMCID: PMC7610538 DOI: 10.1051/0004-6361/202040177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present Yebes 40m telescope observations of the three most stable C4H3N isomers towards the cyanopolyyne peak of TMC-1. We have detected 13 transitions from CH3C3N (A and E species), 16 lines from CH2CCHCN, and 27 lines (a-type and b-type) from HCCCH2CN. We thus provide a robust confirmation of the detection of HCCCH2CN and CH2CCHCN in space. We have constructed rotational diagrams for the three species, and obtained rotational temperatures between 4-8 K and similar column densities for the three isomers, in the range (1.5-3)×1012 cm-2. Our chemical model provides abundances of the order of the observed ones, although it overestimates the abundance of CH3CCCN and underestimates that of HCCCH2CN. The similarity of the observed abundances of the three isomers suggests a common origin, most probably involving reactions of the radical CN with the unsaturated hydrocarbons methyl acetylene and allene. Studies of reaction kinetics at low temperature and further observations of these molecules in different astronomical sources are needed to draw a clear picture of the chemistry of C4H3N isomers in space.
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Affiliation(s)
- N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental, CSIC, C/ Serrano 123, 28006 Madrid, Spain
| | - B. Tercero
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII 3, 28014 Madrid, Spain
- Observatorio de Yebes (IGN). Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental, CSIC, C/ Serrano 123, 28006 Madrid, Spain
| | - J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental, CSIC, C/ Serrano 123, 28006 Madrid, Spain
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8
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Messinger JP, Gupta D, Cooke IR, Okumura M, Sims IR. Rate Constants of the CN + Toluene Reaction from 15 to 294 K and Interstellar Implications. J Phys Chem A 2020; 124:7950-7958. [DOI: 10.1021/acs.jpca.0c06900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph P. Messinger
- Arthur Amos Noyes Laboratory of Chemical Physics, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Divita Gupta
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Ilsa R. Cooke
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Mitchio Okumura
- Arthur Amos Noyes Laboratory of Chemical Physics, Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, United States
| | - Ian R. Sims
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
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9
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Hearne TS, Abdelkader Khedaoui O, Hays BM, Guillaume T, Sims IR. A novel Ka-band chirped-pulse spectrometer used in the determination of pressure broadening coefficients of astrochemical molecules. J Chem Phys 2020; 153:084201. [PMID: 32872880 DOI: 10.1063/5.0017978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A novel chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer has been constructed to cover the Ka-band (26.5 GHz-40 GHz) for use in the CRESUCHIRP project, which aims to study the branching ratios of reactions at low temperatures using the chirped-pulse in uniform flow technique. The design takes advantage of recent developments in radio-frequency components, notably, high-frequency, high-power solid-state amplifiers. The spectrometer had a flatness of 5.5 dB across the spectral range, produced harmonic signals below -20 dBc, and the recorded signal scaled well to 6 × 106 averages. The new spectrometer was used to determine pressure broadening coefficients with a helium collider at room temperature for three molecules relevant to astrochemistry, applying the Voigt function to fit the magnitude of the Fourier-transformed data in the frequency domain. The pressure broadening coefficient for carbonyl sulfide was determined to be (2.45 ± 0.02) MHz mbar-1 at room temperature, which agreed well with previous measurements. Pressure broadening coefficients were also determined for multiple transitions of vinyl cyanide and benzonitrile. Additionally, the spectrometer was coupled with a cold, uniform flow from a Laval nozzle. The spectrum of vinyl cyanide was recorded in the flow, and its rotational temperature was determined to be (24 ± 11) K. This temperature agreed with a prediction of the composite temperature of the system through simulations of the experimental environment coupled with calculations of the solution to the optical Bloch equations. These results pave the way for future quantitative studies in low-temperature and high-pressure environments using CP-FTMW spectroscopy.
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Affiliation(s)
- Thomas S Hearne
- Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | | | - Brian M Hays
- Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Théo Guillaume
- Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Ian R Sims
- Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
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10
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Dhont G, Fontanari D, Bray C, Mouret G, Cuisset A, Hindle F, Hickson KM, Bocquet R. Characterization of the Observed Electric Field and Molecular Relaxation Times for Millimeter-Wave Chirped Pulse Instrumentation. JOURNAL OF INFRARED, MILLIMETER AND TERAHERTZ WAVES 2020; 41:1009-1021. [PMID: 32837589 PMCID: PMC7327489 DOI: 10.1007/s10762-020-00716-z] [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: 02/14/2020] [Accepted: 06/01/2020] [Indexed: 06/11/2023]
Abstract
In a chirped pulse experiment, the strength of the signal level is proportional to the amplitude of the electric field, which is weaker in the millimeter-wave or submillimeter-wave region than in the microwave region. Experiments in the millimeter region thus require an optimization of the coupling between the source and the molecular system and a method to estimate the amplitude of the electric field as seen by the molecular system. We have developed an analytical model capable of reproducing the coherent transient signals obtained with a millimeter-wave chirped pulse setup operated in a monochromatic pulse mode. The fit of the model against the experimental data allowed access to the amplitude of the electric field and, as a byproduct, to the molecular relaxation times T 1 and T 2.
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Affiliation(s)
- G. Dhont
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
| | - D. Fontanari
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
| | - C. Bray
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
| | - G. Mouret
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
| | - A. Cuisset
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
| | - F. Hindle
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
| | - K. M. Hickson
- ISM, Université de Bordeaux, 351 cours de la libération, 33405 Talence cedex, France
| | - R. Bocquet
- LPCA, Université du Littoral Côte d’Opale, 189A avenue Maurice Schumann, 59140 Dunkerque, France
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11
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Benzonitrile as a Proxy for Benzene in the Cold ISM: Low-temperature Rate Coefficients for CN + C6H6. ACTA ACUST UNITED AC 2020. [DOI: 10.3847/2041-8213/ab7a9c] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Toscano J, Lewandowski HJ, Heazlewood BR. Cold and controlled chemical reaction dynamics. Phys Chem Chem Phys 2020; 22:9180-9194. [DOI: 10.1039/d0cp00931h] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
State-to-state chemical reaction dynamics, with complete control over the reaction parameters, offers unparalleled insight into fundamental reactivity.
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Affiliation(s)
- Jutta Toscano
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | | | - Brianna R. Heazlewood
- Physical and Theoretical Chemistry Laboratory (PTCL)
- Department of Chemistry
- University of Oxford
- Oxford
- UK
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13
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Suas-David N, Thawoos S, Suits AG. A uniform flow-cavity ring-down spectrometer (UF-CRDS): A new setup for spectroscopy and kinetics at low temperature. J Chem Phys 2019; 151:244202. [PMID: 31893907 DOI: 10.1063/1.5125574] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The UF-CRDS (Uniform Flow-Cavity Ring Down Spectrometer) is a new setup coupling for the first time a pulsed uniform (Laval) flow with a continuous wave CRDS in the near infrared for spectroscopy and kinetics at low temperature. This high resolution and sensitive absorption spectrometer opens a new window into the phenomena occurring within UFs. The approach extends the detection range to new electronic and rovibrational transitions within Laval flows and offers the possibility to probe numerous species which have not been investigated yet. This new tool has been designed to probe radicals and reaction intermediates but also to follow the chemistry of hydrocarbon chains and PAHs which play a crucial role in the evolution of astrophysical environments. For kinetics measurements, the UF-CRDS combines the CRESU technique (French acronym meaning reaction kinetics in uniform supersonic flows) with the SKaR (Simultaneous Kinetics and Ring-Down) approach where, as indicated by its name, the entire reaction is monitored during each intensity decay within the high finesse cavity. The setup and the approach are demonstrated with the study of the reaction between CN (v = 1) and propene at low temperature. The recorded data are finally consistent with a previous study of the same reaction for CN (v = 0) relying on the CRESU technique with laser induced fluorescence detection.
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Affiliation(s)
- N Suas-David
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | - S Thawoos
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
| | - A G Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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14
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Gupta D, Cheikh Sid Ely S, Cooke IR, Guillaume T, Abdelkader Khedaoui O, Hearne TS, Hays BM, Sims IR. Low Temperature Kinetics of the Reaction Between Methanol and the CN Radical. J Phys Chem A 2019; 123:9995-10003. [DOI: 10.1021/acs.jpca.9b08472] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Divita Gupta
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Sidaty Cheikh Sid Ely
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Ilsa R. Cooke
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Théo Guillaume
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | | | - Thomas S. Hearne
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Brian M. Hays
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Ian R. Sims
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
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15
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Hernandez-Castillo AO, Abeysekera C, Robicheaux F, Zwier TS. Propagating molecular rotational coherences through single-frequency pulses in the strong field regime. J Chem Phys 2019; 151:084312. [PMID: 31470710 DOI: 10.1063/1.5099049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the weak-field limit in which microwave spectroscopy is typically carried out, an application of a single-frequency pulse that is resonant with a molecular transition will create a coherence between the pair of states involved in the rotational transition, producing a free-induction decay (FID) that, after Fourier transform, produces a molecular signal at that same resonance frequency. With the advent of chirped-pulse Fourier transform microwave methods, the high-powered amplifiers needed to produce broadband microwave spectra also open up other experiments that probe the molecular response in the high-field regime. This paper describes a series of experiments involving resonant frequency pulses interrogating jet-cooled molecules under conditions of sufficient power to Rabi oscillate the two-state system through many Rabi cycles. The Fourier-transformed FID shows coherent signal not only at the applied resonant frequency but also at a series of transitions initially connected to the original one by sharing an upper or lower level with it. As the duration of the single-frequency excitation is increased from 250 to 1500 ns, the number of observed off-resonant, but dipole-allowed, molecular coherences grow. The phenomenon is quite general, having been demonstrated in Z-phenylvinylnitrile, E-phenylvinylnitrile (E-PVN), benzonitrile, guaiacol, and 4-pentynenitrile. In E-PVN, the highest power/longest pulse duration, coherent signal is also present at energetically nearby but not directly connected transitions. Even in molecular samples containing more than one independent species, only transitions due to the single species responsible for the original resonant transition are present. We develop a time-dependent model of the molecular/photon system and use it in conjunction with the experiment to test possible sources of the phenomenon.
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Affiliation(s)
| | - Chamara Abeysekera
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | - Timothy S Zwier
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
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16
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Joalland B, Jamal-Eddine N, Papanastasiou D, Lekkas A, Carles S, Biennier L. A mass-selective ion transfer line coupled with a uniform supersonic flow for studying ion–molecule reactions at low temperatures. J Chem Phys 2019; 150:164201. [DOI: 10.1063/1.5086386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- B. Joalland
- Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)—UMR 6251, F-35000 Rennes, France
| | - N. Jamal-Eddine
- Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)—UMR 6251, F-35000 Rennes, France
| | - D. Papanastasiou
- Fasmatech Science and Technology SA, TESPA Lefkippos, NCSR Demokritos, 15310 Athens, Greece
| | - A. Lekkas
- Fasmatech Science and Technology SA, TESPA Lefkippos, NCSR Demokritos, 15310 Athens, Greece
| | - S. Carles
- Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)—UMR 6251, F-35000 Rennes, France
| | - L. Biennier
- Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)—UMR 6251, F-35000 Rennes, France
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17
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Dias N, Joalland B, Ariyasingha NM, Suits AG, Broderick BM. Direct versus Indirect Photodissociation of Isoxazole from Product Branching: A Chirped-Pulse Fourier Transform mm-Wave Spectroscopy/Pulsed Uniform Flow Investigation. J Phys Chem A 2018; 122:7523-7531. [PMID: 30165738 DOI: 10.1021/acs.jpca.8b04713] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The UV photodissociation of isoxazole (c-C3H3NO) is studied in this work by chirped-pulse Fourier transform mm-wave spectroscopy in a pulsed uniform Laval flow. This approach offers a number of advantages over traditional spectroscopic detection methods due to its broadband, sub-MHz resolution, and fast-acquisition capabilities. In coupling this technique with a quasi-uniform Laval flow, we are able to obtain product branching fractions in the 193 nm photodissociation of isoxazole. Five dissociation channels are explored through direct detection of seven different photoproducts. These species and their respective branching fractions (%) include the following: HCN (53.8 ± 1.7), CH3CN (23.4 ± 6.8), HCO (9.5 ± 2.3), CH2CN (7.8 ± 2.9), CH2CO (3.8 ± 0.9), HCCCN (0.9 ± 0.2), and HNC (0.8 ± 0.2). Guided by previous electronic structure and dynamics simulations, we are able to elucidate the dissociation dynamics that govern the final product branching fractions observed in this work, which differ significantly from previous reports on the thermal decomposition of isoxazole. Interestingly, both direct and indirect dynamics contribute to its dissociation, and clear signatures of both are manifested in the relative branching ratios obtained. Consistent with previous studies on the unimolecular dissociation of isoxazole, our findings also suggest the importance of the open-shell singlet diradicaloid species vinylnitrene in the dissociation dynamics, regardless of the initially populated excited state. This work, taken together with previous investigations, provides a global picture of the complex dissociation pathways involved in the photodissociation of isoxazole.
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Affiliation(s)
- Nureshan Dias
- Department of Chemistry, University of Missouri , Columbia , Missouri 65211 , United States
| | - Baptiste Joalland
- Department of Chemistry, University of Missouri , Columbia , Missouri 65211 , United States
| | - Nuwandi M Ariyasingha
- Department of Chemistry, University of Missouri , Columbia , Missouri 65211 , United States
| | - Arthur G Suits
- Department of Chemistry, University of Missouri , Columbia , Missouri 65211 , United States
| | - Bernadette M Broderick
- Department of Chemistry, University of Missouri , Columbia , Missouri 65211 , United States
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18
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Fritz SM, Hays BM, Hernandez-Castillo AO, Abeysekera C, Zwier TS. Multiplexed characterization of complex gas-phase mixtures combining chirped-pulse Fourier transform microwave spectroscopy and VUV photoionization time-of-flight mass spectrometry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:093101. [PMID: 30278727 DOI: 10.1063/1.5046085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/14/2018] [Indexed: 06/08/2023]
Abstract
We report details of the design and operation of a single apparatus that combines Chirped-Pulse Fourier Transform Microwave (CP-FTMW) spectroscopy with vacuum ultraviolet (VUV) photoionization Time-of-Flight Mass Spectrometry (TOFMS). The supersonic expansion used for cooling samples is interrogated first by passing through the region between two microwave horns capable of broadband excitation and detection in the 2-18 GHz frequency region of the microwave. After passing through this region, the expansion is skimmed to form a molecular beam, before being probed with 118 nm (10.5 eV) single-photon VUV photoionization in a linear time-of-flight mass spectrometer. The two detection schemes are powerfully complementary to one another. CP-FTMW detects all components with significant permanent dipole moments. Rotational transitions provide high-resolution structural data. VUV TOFMS provides a gentle and general method for ionizing all components of a gas phase mixture with ionization thresholds below 10.5 eV, providing their molecular formulae. The advantages, complementarity, and limitations of the combined methods are illustrated through results on two gas-phase mixtures made up of (i) three furanic compounds, two of which are structural isomers of one another, and (ii) the effluent from a flash pyrolysis source with o-guaiacol as the precursor.
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Affiliation(s)
- Sean M Fritz
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | - Brian M Hays
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | | | - Chamara Abeysekera
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | - Timothy S Zwier
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
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19
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Jr-Min Lin J, Chao W. Structure-dependent reactivity of Criegee intermediates studied with spectroscopic methods. Chem Soc Rev 2018; 46:7483-7497. [PMID: 28840926 DOI: 10.1039/c7cs00336f] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Criegee intermediates are very reactive carbonyl oxides that are formed in reactions of unsaturated hydrocarbons with ozone (ozonolysis). Recently, Criegee intermediates have gained significant attention since a new preparation method has been reported in 2012, which employs the reaction of iodoalkyl radical with molecular oxygen: for instance, CH2I + O2 → CH2OO + I. This new synthesis route can produce Criegee intermediates with a high number density, which allows direct detection of the Criegee intermediate via various spectroscopic tools, including vacuum UV photoionization mass spectrometry, absorption and action spectroscopy in the UV and IR regions, and microwave spectroscopy. Criegee intermediates have been thought to play important roles in atmospheric chemistry, such as in OH radical formation as well as oxidation of atmospheric gases such as SO2, NO2, volatile organic compounds, organic and inorganic acids, and even water. These reactions are relevant to acid rain and aerosol formation. Kinetics data including rate coefficients, product yields and their temperature and pressure dependences are important for understanding and modeling relevant atmospheric chemistry. In fundamental physical chemistry, Criegee intermediates have unique and interesting features, which have been partially revealed through spectroscopic, kinetic, and dynamic investigations. Although previous review articles have discussed Criegee intermediates, new data and knowledge on Criegee intermediates are still being accumulated. In this tutorial review, we have focused on structure-dependent reactivity of Criegee intermediates and various spectroscopic tools that have been utilized to probe the kinetics of Criegee intermediates.
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Affiliation(s)
- Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
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20
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Broderick BM, Suas-David N, Dias N, Suits AG. Isomer-specific detection in the UV photodissociation of the propargyl radical by chirped-pulse mm-wave spectroscopy in a pulsed quasi-uniform flow. Phys Chem Chem Phys 2018; 20:5517-5529. [PMID: 29165455 DOI: 10.1039/c7cp06211g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Isomer-specific detection and product branching fractions in the UV photodissociation of the propargyl radical is achieved through the use of chirped-pulse Fourier-transform mm-wave spectroscopy in a pulsed quasi-uniform flow (CPUF). Propargyl radicals are produced in the 193 nm photodissociation of 1,2-butadiene. Absorption of a second photon leads to H atom elimination giving three possible C3H2 isomers: singlets cyclopropenylidene (c-C3H2) and propadienylidene (l-C3H2), and triplet propargylene (3HCCCH). The singlet products and their appearance kinetics in the flow are directly determined by rotational spectroscopy, but due to the negligible dipole moment of propargylene, it is not directly monitored. However, we exploit the time-dependent kinetics of H-atom catalyzed isomerization to infer the branching to propargylene as well. We obtain the overall branching among H loss channels to be 2.9% (+1.1/-0.5) l-C3H2 + H, 16.8% (+3.2/-1.3) c-C3H2 + H, and 80.2 (+1.8/-4.2) 3HCCCH + H. Our findings are qualitatively consistent with earlier RRKM calculations in that the major channel in the photodissociation of the propargyl radical at 193 nm is to 3HCCCH + H; however, a greater contribution to the energetically most favorable isomer, c-C3H2 + H is observed in this work. We do not detect the predicted HCCC + H2 channel, but place an upper bound on its yield of 1%.
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Affiliation(s)
- Bernadette M Broderick
- Department of Chemistry, University of Missouri, 601 S. College Ave, Columbia MO 65211, USA.
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21
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Sleiman C, El Dib G, Rosi M, Skouteris D, Balucani N, Canosa A. Low temperature kinetics and theoretical studies of the reaction CN + CH 3NH 2: a potential source of cyanamide and methyl cyanamide in the interstellar medium. Phys Chem Chem Phys 2018; 20:5478-5489. [PMID: 29082409 DOI: 10.1039/c7cp05746f] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction between cyano radicals (which are ubiquitous in interstellar clouds) and methylamine (a molecule detected in various interstellar sources) has been investigated in a synergistic experimental and theoretical study. The reaction has been found to be very fast in the entire range of temperatures investigated (23-297 K) by using a CRESU apparatus coupled to pulsed laser photolysis - laser induced fluorescence. The global experimental rate coefficient is given by In addition, dedicated electronic structure calculations of the underlying potential energy surface have been performed, together with capture theory and RRKM calculations. The experimental data have been interpreted in the light of the theoretical calculations and the product branching ratio has been established. According to the present study, in the range of temperatures investigated the title reaction is an efficient interstellar route of formation of cyanamide, NH2CN, another interstellar species. The second most important channel is the one leading to methyl cyanamide, CH3NHCN (an isomer of aminoacetonitrile), via a CN/H exchange mechanism with a yield of 12% of the global reaction in the entire range of temperatures explored. For a possible inclusion in future astrochemical models we suggest, by referring to the usual expression the following values: α = 3.68 × 10-12 cm3 molec-1 s-1, β = -1.80, γ = 7.79 K for the channel leading to NH2CN + CH3; α = 5.05 × 10-13 cm3 molec-1 s-1, β = -1.82, γ = 7.93 K for the channel leading to CH3NHCN + H.
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Affiliation(s)
- Chantal Sleiman
- Institut de Physique de Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11C, Campus de Beaulieu, 263 Avenue du Général Leclerc, F-35042 Rennes Cedex, France.
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22
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Hammami H, Ben Mohamed F, Mohamed D, Ben El Hadj Rhouma M, Al Mogren MM, Hochlaf M. One-electron pseudo-potential investigation of NO(X 2Π)–Ar n clusters ( n = 1,2,3,4). Mol Phys 2017. [DOI: 10.1080/00268976.2017.1337252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- H. Hammami
- Laboratoire de Recherche d'Etude des Milieux Ionisés et Réactifs (EMIR), Institut Préparatoire aux Etudes d'Ingénieurs, Université de Monastir, Tunisie
| | - F.E. Ben Mohamed
- Laboratoire de Recherche d'Etude des Milieux Ionisés et Réactifs (EMIR), Institut Préparatoire aux Etudes d'Ingénieurs, Université de Monastir, Tunisie
| | - D. Mohamed
- Laboratoire de Recherche d'Etude des Milieux Ionisés et Réactifs (EMIR), Institut Préparatoire aux Etudes d'Ingénieurs, Université de Monastir, Tunisie
| | - M. Ben El Hadj Rhouma
- Laboratoire de Recherche d'Etude des Milieux Ionisés et Réactifs (EMIR), Institut Préparatoire aux Etudes d'Ingénieurs, Université de Monastir, Tunisie
| | - M. M. Al Mogren
- Chemistry Department, Faculty of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - M. Hochlaf
- Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, Université Paris-Est, Marne-la-Vallée, France
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23
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Potapov A, Canosa A, Jiménez E, Rowe B. Chemie mit Überschall: 30 Jahre astrochemische Forschung und künftige Herausforderungen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alexey Potapov
- Laborastrophysikgruppe des Max-Planck-Instituts für Astronomie am Institut für Festkörperphysik; Friedrich-Schiller-Universität Jena; Helmholtzweg 3 07743 Jena Deutschland
| | - André Canosa
- Département de Physique Moléculaire; Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes 1, Campus de Beaulieu; 263 Avenue du Général Leclerc 35042 Rennes Cedex Frankreich
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas; Universidad de Castilla-La Mancha; Avda. Camilo José Cela, 1B 13071 Ciudad Real Spanien
| | - Bertrand Rowe
- Rowe-consulting, 22 Chemin des Moines; 22750 Saint Jacut de la Mer Frankreich
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24
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Potapov A, Canosa A, Jiménez E, Rowe B. Uniform Supersonic Chemical Reactors: 30 Years of Astrochemical History and Future Challenges. Angew Chem Int Ed Engl 2017; 56:8618-8640. [DOI: 10.1002/anie.201611240] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/27/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Alexey Potapov
- Laborastrophysikgruppe des Max-Planck-Instituts für Astronomie am Institut für Festkörperphysik; Friedrich-Schiller-Universität Jena; Helmholtzweg 3 07743 Jena Germany
| | - André Canosa
- Département de Physique Moléculaire; Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes 1, Campus de Beaulieu; 263 Avenue du Général Leclerc 35042 Rennes Cedex France
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas; Universidad de Castilla-La Mancha; Avda. Camilo José Cela, 1B 13071 Ciudad Real Spain
| | - Bertrand Rowe
- Rowe-consulting, 22 Chemin des Moines; 22750 Saint Jacut de la Mer France
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25
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Osborn DL. Reaction Mechanisms on Multiwell Potential Energy Surfaces in Combustion (and Atmospheric) Chemistry. Annu Rev Phys Chem 2017; 68:233-260. [DOI: 10.1146/annurev-physchem-040215-112151] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- David L. Osborn
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550
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26
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Hochlaf M. Advances in spectroscopy and dynamics of small and medium sized molecules and clusters. Phys Chem Chem Phys 2017; 19:21236-21261. [DOI: 10.1039/c7cp01980g] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Investigations of the spectroscopy and dynamics of small- and medium-sized molecules and clusters represent a hot topic in atmospheric chemistry, biology, physics, atto- and femto-chemistry and astrophysics.
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Affiliation(s)
- Majdi Hochlaf
- Université Paris-Est
- Laboratoire Modélisation et Simulation Multi Echelle
- MSME UMR 8208 CNRS
- 77454 Marne-la-Vallée
- France
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27
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Hansen N, Wullenkord J, Obenchain DA, Graf I, Kohse-Höinghaus K, Grabow JU. Microwave spectroscopic detection of flame-sampled combustion intermediates. RSC Adv 2017. [DOI: 10.1039/c7ra06483g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microwave spectroscopy was used to detect and identify combustion intermediates after sampling out of laboratory-scale model flames.
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Affiliation(s)
- N. Hansen
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - J. Wullenkord
- Department of Chemistry
- Bielefeld University
- D-33615 Bielefeld
- Germany
| | - D. A. Obenchain
- Institut für Physikalische Chemie & Elektrochemie
- Gottfried-Wilhelm-Leibniz-University Hannover
- D-30167 Hannover
- Germany
| | - I. Graf
- Department of Chemistry
- Bielefeld University
- D-33615 Bielefeld
- Germany
| | | | - J.-U. Grabow
- Institut für Physikalische Chemie & Elektrochemie
- Gottfried-Wilhelm-Leibniz-University Hannover
- D-30167 Hannover
- Germany
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28
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Custer T, Szczepaniak U, Gronowski M, Fabisiewicz E, Couturier-Tamburelli I, Kołos R. Density Functional Exploration of C4H3N Isomers. J Phys Chem A 2016; 120:5928-38. [PMID: 27341606 DOI: 10.1021/acs.jpca.6b03922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecules having C4H3N stoichiometry are of astrophysical interest. Two of these, methylcyanoacetylene (CH3C3N) and its structural isomer allenyl cyanide (H2CCCHN), have been observed in interstellar space, while several more have been examined in laboratories. Here we describe, for a broad range of C4H3N isomers, density functional calculations (B3LYP/aug-cc-pVTZ) of molecular parameters including the energetics, geometries, rotational constants, electric dipole moments, polarizabilities, vibrational IR frequencies, IR absorption intensities, and Raman activities. Singlet-triplet splittings as well as singlet vertical electronic excitation energies are given for selected species. The identification of less stable C4H3N molecules, generated in ongoing spectroscopic experiments, relies heavily on these quantum chemical predictions.
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Affiliation(s)
- Thomas Custer
- Institute of Physical Chemistry, Polish Academy of Sciences , ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Urszula Szczepaniak
- Institute of Physical Chemistry, Polish Academy of Sciences , ul. Kasprzaka 44/52, 01-224 Warsaw, Poland.,Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Marcin Gronowski
- Institute of Physical Chemistry, Polish Academy of Sciences , ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Emilia Fabisiewicz
- Institute of Physical Chemistry, Polish Academy of Sciences , ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | | | - Robert Kołos
- Institute of Physical Chemistry, Polish Academy of Sciences , ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
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29
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Park GB, Field RW. Perspective: The first ten years of broadband chirped pulse Fourier transform microwave spectroscopy. J Chem Phys 2016; 144:200901. [DOI: 10.1063/1.4952762] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- G. Barratt Park
- Institute for Physical Chemistry, University of Göttingen, Tammannstraße 6, 37077 Göttingen, Germany
- Max Planck Institute for Biophysical Chemistry, Göttingen, Am Faßberg 11, 37077 Göttingen, Germany
| | - Robert W. Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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30
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Preston TJ, Hornung B, Pandit S, Harvey JN, Orr-Ewing AJ. Dynamical Effects and Product Distributions in Simulated CN + Methane Reactions. J Phys Chem A 2016; 120:4672-82. [DOI: 10.1021/acs.jpca.5b09487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas J. Preston
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Balázs Hornung
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Shubhrangshu Pandit
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Jeremy N. Harvey
- Department
of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven (Heverlee), Belgium
| | - Andrew J. Orr-Ewing
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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