1
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Banhatti S, Rap DB, Simon A, Leboucher H, Wenzel G, Joblin C, Redlich B, Schlemmer S, Brünken S. Formation of the acenaphthylene cation as a common C 2H 2-loss fragment in dissociative ionization of the PAH isomers anthracene and phenanthrene. Phys Chem Chem Phys 2022; 24:27343-27354. [PMID: 36326610 PMCID: PMC9673687 DOI: 10.1039/d2cp03835h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/21/2022] [Indexed: 09/19/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are thought to be a major constituent of astrophysical environments, being the carriers of the ubiquitous aromatic infrared bands (AIBs) observed in the spectra of galactic and extra-galactic sources that are irradiated by ultraviolet (UV) photons. Small (2-cycles) PAHs were unambiguously detected in the TMC-1 dark cloud, showing that PAH growth pathways exist even at low temperatures. The processing of PAHs by UV photons also leads to their fragmentation, which has been recognized in recent years as an alternative route to the generally accepted bottom-up chemical pathways for the formation of complex hydrocarbons in UV-rich interstellar regions. Here we consider the C12H8+ ion that is formed in our experiments from the dissociative ionization of the anthracene and phenanthrene (C14H10) molecules. By employing the sensitive action spectroscopic scheme of infrared pre-dissociation (IRPD) in a cryogenic ion trap instrument coupled to the free-electron lasers at the FELIX Laboratory, we have recorded the broadband and narrow line-width gas-phase IR spectra of the fragment ions (C12H8+) and also the reference spectra of three low energy isomers of C12H8+. By comparing the experimental spectra to those obtained from quantum chemical calculations we have identified the dominant structure of the fragment ion formed in the dissociation process to be the acenaphthylene cation for both isomeric precursors. Ab initio molecular dynamics simulations are presented to elucidate the fragmentation process. This result reinforces the dominant role of species containing a pentagonal ring in the photochemistry of small PAHs.
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Affiliation(s)
- Shreyak Banhatti
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Daniël B Rap
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands.
| | - Aude Simon
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Fédération FeRMI, CNRS & Université Toulouse III - Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
| | - Heloïse Leboucher
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Fédération FeRMI, CNRS & Université Toulouse III - Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
| | - Gabi Wenzel
- Center for Interstellar Catalysis (InterCat), Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Christine Joblin
- Institut de Recherche en Astrophysique et Planétologie (IRAP), Université Toulouse III - Paul Sabatier, CNRS, CNES, 9 Avenue du Colonel Roche, 31028 Toulouse, France
| | - Britta Redlich
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands.
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany.
| | - Sandra Brünken
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands.
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2
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Hemberger P, Wu X, Pan Z, Bodi A. Continuous Pyrolysis Microreactors: Hot Sources with Little Cooling? New Insights Utilizing Cation Velocity Map Imaging and Threshold Photoelectron Spectroscopy. J Phys Chem A 2022; 126:2196-2210. [PMID: 35316066 DOI: 10.1021/acs.jpca.2c00766] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Resistively heated silicon carbide microreactors are widely applied as continuous sources to selectively prepare elusive and reactive intermediates with astrochemical, catalytic, or combustion relevance to measure their photoelectron spectrum. These reactors also provide deep mechanistic insights into uni- and bimolecular chemistry. However, the sampling conditions and effects have not been fully characterized. We use cation velocity map imaging to measure the velocity distribution of the molecular beam signal and to quantify the scattered, rethermalized background sample. Although translational cooling is efficient in the adiabatic expansion from the reactor, the breakdown diagrams of methane and chlorobenzene confirm that the molecular beam component exhibits a rovibrational temperature comparable with that of the reactor. Thus, rovibrational cooling is practically absent in the expansion from the microreactor. The high rovibrational temperature also affects the threshold photoelectron spectrum of both benzene and the allyl radical in the molecular beam, but to different degrees. While the extreme broadening of the benzene TPES suggests a complex ionization mechanism, the allyl TPES is in fact consistent with an internal temperature close to that of the reactor. The background, room-temperature spectra of both are superbly reproduced by Franck-Condon simulations at 300 K. On the one hand, this leads us to suggest that room-temperature reference spectra should be used in species identification. On the other hand, analysis of the allyl iodide pyrolysis data shows that iodine atoms often recombine to form molecular iodine on the chamber surfaces. Such sampling effects may distort the chemical composition of the scattered background with respect to the molecular beam signal emanating directly from the reactor. This must be considered in quantitative analyses and kinetic modeling.
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Affiliation(s)
- Patrick Hemberger
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
| | - Xiangkun Wu
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
| | - Zeyou Pan
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
| | - Andras Bodi
- Paul Scherrer Insitute, Forschungsstrasse 111, CH-5232 Villigen PSI, Switzerland
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3
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McCabe MN, Hemberger P, Campisi D, Broxterman JC, Reusch E, Bodi A, Bouwman J. Formation of phenylacetylene and benzocyclobutadiene in the ortho-benzyne + acetylene reaction. Phys Chem Chem Phys 2022; 24:1869-1876. [PMID: 34989380 DOI: 10.1039/d1cp05183k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Ortho-benzyne is a potentially important precursor for polycyclic aromatic hydrocarbon formation, but much is still unknown about its chemistry. In this work, we report on a combined experimental and theoretical study of the o-benzyne + acetylene reaction and employ double imaging threshold photoelectron photoion coincidence spectroscopy to investigate the reaction products with isomer specificity. Based on photoion mass-selected threshold photoelectron spectra, Franck-Condon simulations, and ionization cross section calculations, we conclude that phenylacetylene and benzocyclobutadiene (PA : BCBdiene) are formed at a non-equilibrium ratio of 2 : 1, respectively, in a pyrolysis microreactor at a temperature of 1050 K and a pressure of ∼20 mbar. The C8H6 potential energy surface (PES) is explored to rationalize the formation of the reaction products. Previously unidentified pathways have been found by considering the open-shell singlet (OSS) character of various C8H6 reactive intermediates. Based on the PES data, a kinetic model is constructed to estimate equilibrium abundances of the two products. New insights into the reaction mechanism - with a focus on the OSS intermediates - and the products formed in the o-benzyne + acetylene reaction provide a greater level of understanding of the o-benzyne reactivity during the formation of aromatic hydrocarbons in combustion environments as well as in outflows of carbon-rich stars.
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Affiliation(s)
- Morgan N McCabe
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Dario Campisi
- Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Jeger C Broxterman
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
| | - Engelbert Reusch
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Jordy Bouwman
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands.
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4
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Giustini A, Winfough M, Czekner J, Sztáray B, Meloni G, Bodi A. Photoionization of Two Potential Biofuel Additives: γ-Valerolactone and Methyl Butyrate. J Phys Chem A 2021; 125:10711-10724. [PMID: 34918933 DOI: 10.1021/acs.jpca.1c08033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photoionization of two potential biofuel additives, γ-valerolactone (GVL, C5H8O2) and methyl butyrate (MB, C5H10O2) has been studied by imaging photoelectron photoion coincidence spectroscopy (iPEPICO) at the VUV beamline of the Swiss Light Source (SLS). The vibrational fine structure in the photoelectron spectrum is compared with a Franck-Condon simulation for the electronic ground-state band of the GVL cation. In the lowest energy dissociative photoionization channel of GVL, CO2 is lost, resulting in a 1-butene fragment ion with a 0 K appearance energy of E0 = 10.35 ± 0.01 eV. A newly calculated 1-butene ionization energy of 9.595 ± 0.015 eV establishes the reverse barrier height to CO2 loss as 66.6 ± 4.3 kJ mol-1. Methyl butyrate cations undergo McLafferty rearrangement, which explains the missing ion signal at the computed adiabatic ionization energy of 9.25 eV. After H transfer, ethylene is lost in the lowest energy dissociation channel to yield the methyl acetate enol ion at E0 = 10.24 ± 0.04 eV. This value connects the energetics of methyl butyrate with that of methyl acetate enol ion, which is established at ΔfHo0K[CH2C(OH)OCH3+] = 502 ± 6 kJ mol-1. Parallel to ethylene loss, methyl loss is also observed from the enol tautomer of the parent ion. Both samples exhibit low-energy nonstatistical dissociative ionization channels. In GVL, the methyl-loss abundance rises quickly but levels off suddenly in the energy range of the first electronically excited states, indicating nonstatistical competition between CH3 and CO2 loss. In MB, the major parallel dissociation channel is the loss of a methoxy radical. Calculations indicate that McLafferty rearrangement is inhibited on the excited-state surface. Indeed, breakdown curve modeling of this and a sequential CO-loss channel confirms a second statistical regime in dissociative photoionization, decoupled from ethylene loss.
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Affiliation(s)
- Andrea Giustini
- Dipartimento di Scienze Fisiche e Chimiche, University of L'Aquila, 67100 L'Aquila, Italy
| | - Matthew Winfough
- Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, California 94117-1080, United States
| | - Joseph Czekner
- Institut für Physikalische Chemie II, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
| | - Bálint Sztáray
- Department of Chemistry, University of the Pacific, 3601 Pacific Avenue, Stockton, California 95211, United States
| | - Giovanni Meloni
- Dipartimento di Scienze Fisiche e Chimiche, University of L'Aquila, 67100 L'Aquila, Italy.,Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, California 94117-1080, United States
| | - Andras Bodi
- Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institut (PSI), 5232 Villigen, Switzerland
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5
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Puente‐Urbina A, Pan Z, Paunović V, Šot P, Hemberger P, van Bokhoven JA. Direct Evidence on the Mechanism of Methane Conversion under Non-oxidative Conditions over Iron-modified Silica: The Role of Propargyl Radicals Unveiled. Angew Chem Int Ed Engl 2021; 60:24002-24007. [PMID: 34459534 PMCID: PMC8596584 DOI: 10.1002/anie.202107553] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Indexed: 11/08/2022]
Abstract
Radical-mediated gas-phase reactions play an important role in the conversion of methane under non-oxidative conditions into olefins and aromatics over iron-modified silica catalysts. Herein, we use operando photoelectron photoion coincidence spectroscopy to disentangle the elusive C2+ radical intermediates participating in the complex gas-phase reaction network. Our experiments pinpoint different C2 -C5 radical species that allow for a stepwise growth of the hydrocarbon chains. Propargyl radicals (H2 C-C≡C-H) are identified as essential precursors for the formation of aromatics, which then contribute to the formation of heavier hydrocarbon products via hydrogen abstraction-acetylene addition routes (HACA mechanism). These results provide comprehensive mechanistic insights that are relevant for the development of methane valorization processes.
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Affiliation(s)
- Allen Puente‐Urbina
- Institute for Chemical and BioengineeringDepartment of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 1–5/108093ZurichSwitzerland
| | - Zeyou Pan
- Institute for Chemical and BioengineeringDepartment of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 1–5/108093ZurichSwitzerland
- Laboratory for Synchrotron Radiation and FemtochemistryPaul Scherrer InstituteForschungsstrasse 1115232VilligenSwitzerland
| | - Vladimir Paunović
- Institute for Chemical and BioengineeringDepartment of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 1–5/108093ZurichSwitzerland
| | - Petr Šot
- Institute for Chemical and BioengineeringDepartment of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 1–5/108093ZurichSwitzerland
- Laboratory of Inorganic ChemistryDepartment of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 1–5/108093ZurichSwitzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and FemtochemistryPaul Scherrer InstituteForschungsstrasse 1115232VilligenSwitzerland
| | - Jeroen Anton van Bokhoven
- Institute for Chemical and BioengineeringDepartment of Chemistry and Applied BiosciencesETH ZurichVladimir-Prelog-Weg 1–5/108093ZurichSwitzerland
- Laboratory for Catalysis and Sustainable ChemistryPaul Scherrer InstituteForschungsstrasse 1115232VilligenSwitzerland
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6
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Puente‐Urbina A, Pan Z, Paunović V, Šot P, Hemberger P, Bokhoven JA. Direct Evidence on the Mechanism of Methane Conversion under Non‐oxidative Conditions over Iron‐modified Silica: The Role of Propargyl Radicals Unveiled. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Allen Puente‐Urbina
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1–5/10 8093 Zurich Switzerland
| | - Zeyou Pan
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1–5/10 8093 Zurich Switzerland
- Laboratory for Synchrotron Radiation and Femtochemistry Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen Switzerland
| | - Vladimir Paunović
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1–5/10 8093 Zurich Switzerland
| | - Petr Šot
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1–5/10 8093 Zurich Switzerland
- Laboratory of Inorganic Chemistry Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1–5/10 8093 Zurich Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen Switzerland
| | - Jeroen Anton Bokhoven
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1–5/10 8093 Zurich Switzerland
- Laboratory for Catalysis and Sustainable Chemistry Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen Switzerland
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7
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Muresan M, Subramanian H, Sibi MP, Green JR. Propargyl Radicals in Organic Synthesis. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Marcus Muresan
- Department of Chemistry and Biochemistry University of Windsor 401 Sunset Ave. Windsor Ontario N9B 3P4 Canada
| | - Hariharaputhiran Subramanian
- Department of Chemistry and Biochemistry North Dakota State University Dept 2735 PO Box 6050 Fargo North Dakota 58108-6050 USA
| | - Mukund P. Sibi
- Department of Chemistry and Biochemistry North Dakota State University Dept 2735 PO Box 6050 Fargo North Dakota 58108-6050 USA
| | - James R. Green
- Department of Chemistry and Biochemistry University of Windsor 401 Sunset Ave. Windsor Ontario N9B 3P4 Canada
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8
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Cernicharo J, Agúndez M, Cabezas C, Tercero B, Marcelino N, Pardo JR, de Vicente P. Pure hydrocarbon cycles in TMC-1: Discovery of ethynyl cyclopropenylidene, cyclopentadiene and indene. ASTRONOMY AND ASTROPHYSICS 2021; 649:L15. [PMID: 34257463 PMCID: PMC7611194 DOI: 10.1051/0004-6361/202141156] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c-C3HCCH (ethynyl cyclopropenylidene), c-C5H6 (cyclopentadiene) and c-C9H8 (indene). We derive a column density of 3.1 × 1011 cm-2 for the former cycle and similar values, in the range (1-2) × 1013 cm-2, for the two latter molecules. This means that cyclopentadiene and indene, in spite of their large size, are exceptionally abundant, only a factor of five less abundant than the ubiquitous cyclic hydrocarbon c-C3H2. The high abundance found for these two hydrocarbon cycles, together with the high abundance previously found for the propargyl radical (CH2CCH) and other hydrocarbons like vinyl and allenyl acetylene (Agúndez et al. 2021; Cernicharo et al. 2021a,b), start to allow us to quantify the abundant content of hydrocarbon rings in cold dark clouds and to identify the intermediate species that are probably behind the in situ bottom-up synthesis of aromatic cycles in these environments. While c-C3HCCH is most likely formed through the reaction between the radical CCH and c-C3H2, the high observed abundances of cyclopentadiene and indene are difficult to explain through currently proposed chemical mechanisms. Further studies are needed to identify how are five- and six-membered rings formed under the cold conditions of clouds like TMC-1.
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Affiliation(s)
- J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
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9
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Grimm S, Baik SJ, Hemberger P, Bodi A, Kempf AM, Kasper T, Atakan B. Gas-phase aluminium acetylacetonate decomposition: revision of the current mechanism by VUV synchrotron radiation. Phys Chem Chem Phys 2021; 23:15059-15075. [PMID: 34231583 DOI: 10.1039/d1cp00720c] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although aluminium acetylacetonate, Al(C5H7O2)3, is a common precursor for chemical vapor deposition (CVD) of aluminium oxide, its gas-phase decomposition is not well-known. Here, we studied its thermal decomposition in a microreactor by double imaging photoelectron photoion coincidence spectroscopy (i2PEPICO) between 325 and 1273 K. The reactor flow field was characterized by CFD. Quantum chemical calculations were used for the assignment of certain species. The dissociative ionization of the room temperature precursor molecule starts at a photon energy of 8.5 eV by the rupture of the bond to an acetylacetonate ligand leading to the formation of the Al(C5H7O2)2+ ion. In pyrolysis experiments, up to 49 species were detected and identified in the gas-phase, including reactive intermediates and isomeric/isobaric hydrocarbons, oxygenated species as well as aluminium containing molecules. We detected aluminium bis(diketo)acetylacetonate-H, Al(C5H7O2)C5H6O2, at m/z 224 together with acetylacetone (C5H8O2) as the major initial products formed at temperatures above 600 K. A second decomposition channel affords Al(OH)2(C5H7O2) along with the formation of a substituted pentalene ring species (C10H12O2) as assigned by Franck-Condon simulations and quantum chemical calculations. Acetylallene (C5H6O), acetone (C3H6O) and ketene (C2H2O) were major secondary decomposition products, formed upon decomposition of the primary products. Three gas-phase aromatic hydrocarbons were also detected and partially assigned for the first time: m/z 210, m/z 186 (C14H18 or C12H10O2) and m/z 146 (C11H14 or C9H6O2) and their formation mechanism is discussed. Finally, Arrhenius parameters are presented on the gas-phase decomposition kinetics of Al(C5H7O2)3, aided by numerical simulation of the flow field.
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Affiliation(s)
- Sebastian Grimm
- University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Thermodynamics, Duisburg 47057, Germany. and Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany
| | - Seung-Jin Baik
- Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany and University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Fluid Dynamics, Duisburg 47057, Germany
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH-5232 Villigen-PSI, Switzerland
| | - Andreas M Kempf
- Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany and University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Fluid Dynamics, Duisburg 47057, Germany
| | - Tina Kasper
- Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany and University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Mass Spectrometry of Reactive Fluids, Duisburg 47057, Germany
| | - Burak Atakan
- University of Duisburg-Essen, Institute of Combustion and Gas Dynamics, Chair of Thermodynamics, Duisburg 47057, Germany. and Center for NanoIntegration Duisburg-Essen (CENIDE), Duisburg 47057, Germany
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10
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McCabe M, Hemberger P, Reusch E, Bodi A, Bouwman J. Off the Beaten Path: Almost Clean Formation of Indene from the ortho-Benzyne + Allyl Reaction. J Phys Chem Lett 2020; 11:2859-2863. [PMID: 32202794 PMCID: PMC7168585 DOI: 10.1021/acs.jpclett.0c00374] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/23/2020] [Indexed: 06/07/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) play an important role in chemistry both in the terrestrial setting and in the interstellar medium. Various, albeit often inefficient, chemical mechanisms have been proposed to explain PAH formation, but few yield polycyclic hydrocarbons cleanly. Alternative and quite promising pathways have been suggested to address these shortcomings with key starting reactants including resonance stabilized radicals (RSRs) and o-benzyne. Here we report on a combined experimental and theoretical study of the reaction allyl + o-benzyne. Indene was found to be the primary product and statistical modeling predicts only 0.1% phenylallene and 0.1% 3-phenyl-1-propyne as side products. The quantitative and likely barrierless formation of indene yields important insights into the role resonance stabilized radicals play in the formation of polycyclic hydrocarbons.
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Affiliation(s)
- Morgan
N. McCabe
- Laboratory
for Astrophysics, Leiden Observatory, Leiden
University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
| | - Patrick Hemberger
- Laboratory
for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Engelbert Reusch
- Institute
of Physical and Theoretical Chemistry, University
of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Andras Bodi
- Laboratory
for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Jordy Bouwman
- Laboratory
for Astrophysics, Leiden Observatory, Leiden
University, P.O. Box 9513, 2300 RA Leiden, The Netherlands
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11
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Bouwman J, Bodi A, Hemberger P. Nitrogen matters: the difference between PANH and PAH formation. Phys Chem Chem Phys 2018; 20:29910-29917. [DOI: 10.1039/c8cp05830j] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Because of the large stability of the nitrile group, the N-substituted aromatic molecule quinoline does not form in the phenyl + acrylonitrile reaction, in contrast to naphthalene formation in the isoelectronic phenyl + vinylacetylene reaction.
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Affiliation(s)
- Jordy Bouwman
- Sackler Laboratory for Astrophysics
- Leiden Observatory
- Leiden University
- NL 2300 RA Leiden
- The Netherlands
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry
- Paul Scherrer Institute
- 5232 Villigen
- Switzerland
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12
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Pastoors JIM, Bodi A, Hemberger P, Bouwman J. Dissociative Ionization and Thermal Decomposition of Cyclopentanone. Chemistry 2017; 23:13131-13140. [PMID: 28692134 PMCID: PMC5639375 DOI: 10.1002/chem.201702376] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Indexed: 11/24/2022]
Abstract
Despite the growing use of renewable and sustainable biofuels in transportation, their combustion chemistry is poorly understood, limiting our efforts to reduce harmful emissions. Here we report on the (dissociative) ionization and the thermal decomposition mechanism of cyclopentanone, studied using imaging photoelectron photoion coincidence spectroscopy. The fragmentation of the ions is dominated by loss of CO, C2H4, and C2H5, leading to daughter ions at m/z 56 and 55. Exploring the C5H8O.+ potential energy surface reveals hydrogen tunneling to play an important role in low‐energy decarbonylation and probably also in the ethene‐loss processes, yielding 1‐butene and methylketene cations, respectively. At higher energies, pathways without a reverse barrier open up to oxopropenyl and cyclopropanone cations by ethyl‐radical loss and a second ethene‐loss channel, respectively. A statistical Rice–Ramsperger–Kassel–Marcus model is employed to test the viability of this mechanism. The pyrolysis of cyclopentanone is studied at temperatures ranging from about 800 to 1100 K. Closed‐shell pyrolysis products, namely 1,3‐butadiene, ketene, propyne, allene, and ethene, are identified based on their photoion mass‐selected threshold photoelectron spectrum. Furthermore, reactive radical species such as allyl, propargyl, and methyl are found. A reaction mechanism is derived incorporating both stable and reactive species, which were not predicted in prior computational studies.
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Affiliation(s)
- Johan I M Pastoors
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland
| | - Jordy Bouwman
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands.,Present address: Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden, The Netherlands
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13
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Sztáray B, Voronova K, Torma KG, Covert KJ, Bodi A, Hemberger P, Gerber T, Osborn DL. CRF-PEPICO: Double velocity map imaging photoelectron photoion coincidence spectroscopy for reaction kinetics studies. J Chem Phys 2017; 147:013944. [DOI: 10.1063/1.4984304] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Bálint Sztáray
- Department of Chemistry, University of the Pacific, Stockton, California 95211, USA
| | - Krisztina Voronova
- Department of Chemistry, University of the Pacific, Stockton, California 95211, USA
| | - Krisztián G. Torma
- Department of Chemistry, University of the Pacific, Stockton, California 95211, USA
| | - Kyle J. Covert
- Department of Chemistry, University of the Pacific, Stockton, California 95211, USA
| | - Andras Bodi
- Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - Thomas Gerber
- Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
| | - David L. Osborn
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA
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14
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Wu X, Zhou X, Hemberger P, Bodi A. Dissociative Photoionization of Dimethyl Carbonate: The More It Is Cut, the Bigger the Fragment Ion. J Phys Chem A 2017; 121:2748-2759. [DOI: 10.1021/acs.jpca.7b00544] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiangkun Wu
- Hefei
National Laboratory for Physical Sciences at the Microscale and Department
of Chemical Physics, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China
| | - Xiaoguo Zhou
- Hefei
National Laboratory for Physical Sciences at the Microscale and Department
of Chemical Physics, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China
| | - Patrick Hemberger
- Laboratory
for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Andras Bodi
- Laboratory
for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institute, 5232 Villigen, Switzerland
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15
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Holzmeier F, Wagner I, Fischer I, Bodi A, Hemberger P. Pyrolysis of 3-Methoxypyridine. Detection and Characterization of the Pyrrolyl Radical by Threshold Photoelectron Spectroscopy. J Phys Chem A 2016; 120:4702-10. [DOI: 10.1021/acs.jpca.5b10743] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fabian Holzmeier
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland D-97074, Germany
| | - Isabella Wagner
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland D-97074, Germany
| | - Ingo Fischer
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland D-97074, Germany
| | - Andras Bodi
- Molecular
Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen
PSI, Switzerland
| | - Patrick Hemberger
- Molecular
Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen
PSI, Switzerland
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16
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Constantinidis P, Schmitt HC, Fischer I, Yan B, Rijs AM. Formation of polycyclic aromatic hydrocarbons from bimolecular reactions of phenyl radicals at high temperatures. Phys Chem Chem Phys 2015; 17:29064-71. [DOI: 10.1039/c5cp05354d] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The self-reaction of the phenyl radical is one of the key reactions in combustion chemistry.
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Affiliation(s)
- P. Constantinidis
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- Am Hubland
- D-97074 Würzburg
- Germany
| | - H.-C. Schmitt
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- Am Hubland
- D-97074 Würzburg
- Germany
| | - I. Fischer
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- Am Hubland
- D-97074 Würzburg
- Germany
| | - B. Yan
- Radboud University
- Institute for Molecules and Materials
- FELIX Laboratory
- Toernooiveld 7-c
- 6525 ED Nijmegen
| | - A. M. Rijs
- Radboud University
- Institute for Molecules and Materials
- FELIX Laboratory
- Toernooiveld 7-c
- 6525 ED Nijmegen
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