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van der Burgt PJM, Gradziel ML. Coincidence mass spectrometry study of double ionization of pyrene by 70 eV electron impact. Phys Chem Chem Phys 2024; 26:10688-10697. [PMID: 38511630 DOI: 10.1039/d4cp00443d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
We have performed coincidence mass spectrometry of fragmentation of pyrene molecules by 70 eV electron impact. Ionized fragments have been mass selected using a reflectron time-of-flight mass spectrometer, and a field programmable gate array has been used for the timing of the electron and ion extraction pulses and for the event-by-event detection of the ions. Double ionization results in a number of prominent fragmentations producing two singly-ionized fragments with kinetic energies of up to a few eV. A number of fragmentations produce ions with four or more carbon atoms, which can only be formed by the breaking of at least three C-C bonds.
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Affiliation(s)
- Peter J M van der Burgt
- Department of Experimental Physics, National University of Ireland Maynooth, Maynooth, Co, Kildare, Ireland.
| | - Marcin L Gradziel
- Department of Experimental Physics, National University of Ireland Maynooth, Maynooth, Co, Kildare, Ireland.
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Caster KL, Selby TM, Osborn DL, Le Picard SD, Goulay F. Product Detection of the CH(X 2Π) Radical Reaction with Cyclopentadiene: A Novel Route to Benzene. J Phys Chem A 2021; 125:6927-6939. [PMID: 34374546 DOI: 10.1021/acs.jpca.1c03517] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of the methylidyne radical (CH(X2Π)) with cyclopentadiene (c-C5H6) is studied in the gas phase at 4 Torr and 373 K using a multiplexed photoionization mass spectrometer. Under multiple collision conditions, the dominant product channel observed is the formation of C6H6 + H. Fitting the photoionization spectrum using reference spectra allows for isomeric resolution of C6H6 isomers, where benzene is the largest contributor with a relative branching fraction of 90 (±5)%. Several other C6H6 isomers are found to have smaller contributions, including fulvene with a branching fraction of 8 (±5)%. Master Equation calculations for four different entrance channels on the C6H7 potential energy surface are performed to explore the competition between CH cycloaddition to a C═C bond vs CH insertion into C-H bonds of cyclopentadiene. Previous studies on CH addition to unsaturated hydrocarbons show little evidence for the C-H insertion pathway. The present computed branching fractions support benzene as the sole cyclic product from CH cycloaddition, whereas fulvene is the dominant product from two of the three pathways for CH insertion into the C-H bonds of cyclopentadiene. The combination of experiment with Master Equation calculations implies that insertion must account for ∼10 (±5)% of the overall CH + cyclopentadiene mechanism.
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Affiliation(s)
- Kacee L Caster
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Talitha M Selby
- Department of Mathematics and Natural Sciences, University of Wisconsin-Milwaukee, West Bend, Wisconsin 53095, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551, United States
| | - Sebastien D Le Picard
- IPR (Institut de Physique de Rennes), UMR 6251, Univ Rennes, CNRS, F-35000 Rennes, France
| | - Fabien Goulay
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
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Chakraborty A, Lee YP. Formation and infrared identification of protonated fluoranthene isomers 3-, 9-, and 10-C 16H 11+ in solid para-H 2. Phys Chem Chem Phys 2019; 21:1820-1829. [PMID: 30628616 DOI: 10.1039/c8cp05849k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAH) and their derivatives are prospective carriers of unidentified infrared (UIR) emission features observed in interstellar media. Fluoranthene (C16H10) is a simple planar PAH with five- and six-membered rings; it can be considered as a fragment of C60, which, along with its cationic counterpart, has been identified in interstellar media. Protonated fluoranthene, C16H11+, was generated upon electron bombardment during deposition at 3.2 K of p-H2 containing fluoranthene in a small proportion. The intensities of infrared features of C16H11+ decreased after maintaining the matrix in darkness because of its neutralization with trapped electrons. According to the correlations in intensities upon neutralization and secondary photolysis, observed lines were classified into three groups which are assigned to isomers 3-C16H11+, 9-C16H11+, and 10-C16H11+. Experimental vibrational wavenumbers and relative IR intensities of the features agree with corresponding calculated values predicted for these three isomers of C16H11+ with the B3PW91/6-311++G(2d,2p) method. 3-C16H11+ and 9-C16H11+ are predicted to have the lowest energy (within 5 kJ mol-1), whereas 10- and 1-C16H11+ are lying above the global minimum 3-C16H11+ by ∼20 kJ mol-1. However, definitive identification of 1-C16H11+ could not be made as only the most intense line is tentatively assigned. Although the observed spectra of these isomers match unsatisfactorily with the UIR bands, they will facilitate the potential terrestrial and extraterrestrial identification of these species.
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Affiliation(s)
- Arghya Chakraborty
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan.
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Steber AL, Pérez C, Temelso B, Shields GC, Rijs AM, Pate BH, Kisiel Z, Schnell M. Capturing the Elusive Water Trimer from the Stepwise Growth of Water on the Surface of the Polycyclic Aromatic Hydrocarbon Acenaphthene. J Phys Chem Lett 2017; 8:5744-5750. [PMID: 29112436 DOI: 10.1021/acs.jpclett.7b02695] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are key players in reaction chemistry. While it is postulated that they serve as a basis for ice grains, there has been no direct detection of PAHs in astronomical environments. We aim to investigate the hydration of PAHs to set a foundation for the future exploration of potential ice formation pathways. We report results from chirped pulse Fourier transform microwave spectroscopy and quantum-chemical calculations for the PAH acenaphthene and acenaphthene complexed with up to four water molecules. The acenaphthene-(H2O)3 complex is of particular interest as the elusive cyclic water trimer was observed. It appears in a slightly distorted configuration when compared with the pure water trimer. This is explained by hydrogen-bond net cooperativity effects. Binding energies for the complexes are presented. Our results provide insight into the onset of complex aggregation that could be occurring in extraterrestrial environments as part of ice grain formation.
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Affiliation(s)
- Amanda L Steber
- Deutsches Elektronen-Synchrotron , Notkestrasse 85, D-22607 Hamburg, Germany
- Max-Planck-Institut für Struktur und Dynamik der Materie , Luruper Chaussee 149, D-22761 Hamburg, Germany
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Max-Eyth-Strasse 1, D-24118 Kiel, Germany
- The Hamburg Centre for Ultrafast Imaging , Luruper Chaussee 149, D-22761 Hamburg, Germany
| | - Cristóbal Pérez
- Deutsches Elektronen-Synchrotron , Notkestrasse 85, D-22607 Hamburg, Germany
- Max-Planck-Institut für Struktur und Dynamik der Materie , Luruper Chaussee 149, D-22761 Hamburg, Germany
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Max-Eyth-Strasse 1, D-24118 Kiel, Germany
- The Hamburg Centre for Ultrafast Imaging , Luruper Chaussee 149, D-22761 Hamburg, Germany
| | - Berhane Temelso
- Provost's Office and Department of Chemistry, Furman University , Greenville, South Carolina 29613, United States
| | - George C Shields
- Provost's Office and Department of Chemistry, Furman University , Greenville, South Carolina 29613, United States
| | - Anouk M Rijs
- Radboud University , Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7-c, 6525 ED Nijmegen, The Netherlands
| | - Brooks H Pate
- Department of Chemistry, University of Virginia , Charlottesville, Virginia 22904, United States
| | - Zbigniew Kisiel
- Institute of Physics, Polish Academy of Sciences , PL-02668 Warsaw, Poland
| | - Melanie Schnell
- Deutsches Elektronen-Synchrotron , Notkestrasse 85, D-22607 Hamburg, Germany
- Max-Planck-Institut für Struktur und Dynamik der Materie , Luruper Chaussee 149, D-22761 Hamburg, Germany
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel , Max-Eyth-Strasse 1, D-24118 Kiel, Germany
- The Hamburg Centre for Ultrafast Imaging , Luruper Chaussee 149, D-22761 Hamburg, Germany
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Guzmán VV, Pety J, Goicoechea JR, Gerin M, Roueff E, Gratier P, Öberg KI. SPATIALLY RESOLVED
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EMISSION IN THE HORSEHEAD PHOTODISSOCIATION REGION: FURTHER EVIDENCE FOR A TOP-DOWN HYDROCARBON CHEMISTRY. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/2041-8205/800/2/l33] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Esselman BJ, Amberger BK, Shutter JD, Daane MA, Stanton JF, Woods RC, McMahon RJ. Rotational spectroscopy of pyridazine and its isotopologs from 235–360 GHz: Equilibrium structure and vibrational satellites. J Chem Phys 2013; 139:224304. [DOI: 10.1063/1.4832899] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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