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Mebel AM, Li W, Pratali Maffei L, Cavallotti C, Morozov AN, Wang CY, Yang JZ, Zhao L, Kaiser RI. Fulvenallenyl Radical (C 7H 5·)-Mediated Gas-Phase Synthesis of Bicyclic Aromatic C 10H 8 Isomers: Can Fulvenallenyl Efficiently React with Closed-Shell Hydrocarbons? J Phys Chem A 2024; 128:5707-5720. [PMID: 38967960 DOI: 10.1021/acs.jpca.4c02386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
To understand the reactivity of resonantly stabilized radicals, often found in relevant concentrations in gaseous environments, it is important to determine their main reaction pathways. Here, it is investigated whether the fulvenallenyl radical (C7H5·) reacts preferentially with closed-shell molecules or radicals. Electronic structure calculations on the C10H9 potential energy surface accessed by the reactions of C7H5· with methylacetylene (CH3CCH) and allene (H2CCCH2) were combined with RRKM-ME calculations of temperature- and pressure-dependent rate constants using the automated EStokTP software suite and kinetic modeling to assess the reactivity of C7H5· with closed-shell unsaturated hydrocarbons. Experimentally, the reactions were attempted in a chemical microreactor heated to 998 ± 10 K by preparing fulvenallenyl radicals via pyrolysis of trichloromethylbenzene (C7H5Cl3) and seeding the radicals in methylacetylene or allene carrier gas, with product identification by means of photoionization mass spectrometry. The measured photoionization efficiency curve of m/z = 128 was assigned to a linear combination of the reference curves of two C10H8 isomers, azulene (minor) and naphthalene (major), presumably resulting from the C7H5· plus C3H4 reactions. However, the calculations demonstrated that these reactions are too slow, and kinetic modeling of processes in the reactor allowed us to conclude that the observation of naphthalene and azulene is due to the C7H5· plus C3H3· reaction, where propargyl is produced by direct hydrogen atom abstraction by chlorine (Cl) atoms from allene or methylacetylene and Cl stem from the pyrolysis of C7H5Cl3. Modeling results under the copyrolysis conditions of toluene and methylacetylene in high-temperature shock tube experiments confirmed the prevalence of the fulvenallenyl reaction with propargyl over its reactions with C3H4 even when the concentrations of allene and methylacetylene largely exceed that of propargyl. Overall, the reactions of fulvenallenyl with both allene and methylacetylene were found to be noncompetitive in the formation of naphthalene and azulene thus attesting the inefficiency of the fulvenallenyl radical reactions with the prototype closed-shell hydrocarbon species. In the meantime, the new reaction pathways revealed, including H-assisted isomerizations between C10H8 isomers and decomposition reactions of various C10H9 isomers, emerge as relevant and are recommended for inclusion in combustion kinetic models for naphthalene formation.
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Affiliation(s)
- Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Wang Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Luna Pratali Maffei
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Carlo Cavallotti
- Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alexander N Morozov
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Chang-Yang Wang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Jiu-Zhong Yang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Long Zhao
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230027, China
- Deep Space Exploration Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96888, United States
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2
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Li W, Yang J, Zhao L, Couch D, Marchi MS, Hansen N, Morozov AN, Mebel AM, Kaiser RI. Gas-phase preparation of azulene (C 10H 8) and naphthalene (C 10H 8) via the reaction of the resonantly stabilized fulvenallenyl and propargyl radicals. Chem Sci 2023; 14:9795-9805. [PMID: 37736626 PMCID: PMC10510771 DOI: 10.1039/d3sc03231k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 08/23/2023] [Indexed: 09/23/2023] Open
Abstract
Synthetic routes to the 10π Hückel aromatic azulene (C10H8) molecule, the simplest polycyclic aromatic hydrocarbon carrying an adjacent five- and seven-membered ring, have been of fundamental importance due to the role of azulene - a structural isomer of naphthalene - as an essential molecular building block of saddle-shaped carbonaceous nanostructures such as curved nanographenes and nanoribbons. Here, we report on the very first gas phase preparation of azulene by probing the gas-phase reaction between two resonantly stabilized radicals, fulvenallenyl and propargyl , in a molecular beam through isomer-resolved vacuum ultraviolet photoionization mass spectrometry. Augmented by electronic structure calculations, the novel Fulvenallenyl Addition Cyclization Aromatization (FACA) reaction mechanism affords a versatile concept for introducing the azulene moiety into polycyclic aromatic systems thus facilitating an understanding of barrierless molecular mass growth processes of saddle-shaped aromatics and eventually carbonaceous nanoparticles (soot, interstellar grains) in our universe.
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Affiliation(s)
- Wang Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China Hefei Anhui 230029 China
| | - Jiuzhong Yang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China Hefei Anhui 230029 China
| | - Long Zhao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China Hefei Anhui 230029 China
- School of Nuclear Science and Technology, University of Science and Technology of China Hefei Anhui 230027 China
| | - David Couch
- Combustion Research Facility, Sandia National Laboratories Livermore CA 94551 USA
| | - Myrsini San Marchi
- Combustion Research Facility, Sandia National Laboratories Livermore CA 94551 USA
| | - Nils Hansen
- Combustion Research Facility, Sandia National Laboratories Livermore CA 94551 USA
| | - Alexander N Morozov
- Department of Chemistry and Biochemistry, Florida International University Miami FL 33199 USA
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University Miami FL 33199 USA
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawaii at Manoa Honolulu HI 96822 USA
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3
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Hirsch F, Fischer I, Bakels S, Rijs AM. Gas-Phase Infrared Spectra of the C 7H 5 Radical and Its Bimolecular Reaction Products. J Phys Chem A 2022; 126:2532-2540. [PMID: 35427137 DOI: 10.1021/acs.jpca.2c01228] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Resonance-stabilized radicals are considered as possible intermediates in the formation of polycyclic aromatic hydrocarbons (PAHs) in interstellar space. Here, we investigate the fulvenallenyl radical, the most stable C7H5 isomer by IR/UV ion dip spectroscopy employing free electron laser radiation in the mid-infrared region between 550 and 1750 cm-1. The radical is generated by pyrolysis from phthalide. Various jet-cooled reaction products are identified by their mass-selective IR spectra in the fingerprint region, based on a comparison with computed spectra. Interestingly, benzyl is present as a second resonance-stabilized radical. It is connected to fulvenallenyl by a sequence of two H atom losses or additions. Among the identified aromatic hydrocarbons are toluene and styrene, as well as polycyclic molecules, such as indene, naphthalene, fluorene and phenanthrene. Mechanisms for the formation of PAH from C7H5 have already been suggested in previous computational work. In particular, the radical/radical reaction of two fulvenallenyl radicals provides an efficient route to phenanthrene in one bimolecular step and might be relevant for PAH formation under astrochemical conditions.
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Affiliation(s)
- Florian Hirsch
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Sjors Bakels
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Anouk M Rijs
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
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4
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Li D, Xu J, Xu X, Yang W, Jian J. Matrix Infrared Spectra of 1-Ethynyl-1H-Silole Species from Reaction of Silicon Atoms with Benzene. Phys Chem Chem Phys 2022; 24:4978-4986. [DOI: 10.1039/d1cp05245d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of silicon atoms with benzene molecule in solid neon are studied by matrix isolation infrared spectroscopy. Aided by carbon-13 and deuterium isotopic shifts as well as quantum-chemical predictions,...
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5
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Chin CH, Zhu T, Zhang JZH. Cyclopentadienyl radical formation from the reaction of excited nitrogen atoms with benzene: a theoretical study. Phys Chem Chem Phys 2021; 23:12408-12420. [PMID: 34027937 DOI: 10.1039/d1cp00133g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ab initio CCSD(T)/CBS//ωB97X-D/6-311+G(d,p) calculations of the C6H6N potential energy surface were performed to investigate the reaction mechanism underlying the reaction of atomic nitrogen (2D) with benzene. Thereafter, Rice-Ramsperger-Kassel-Marcus (RRKM) calculations of reaction rate constants and product branching ratios were performed under single-collision conditions. The results revealed that the N(2D) + C6H6 reaction in the case of statistical behavior is expected to produce hydrogen cyanide plus a cyclopentadienyl radical (91.5-88.9%), acetylene plus a pyrrole radical (5.8-7.5%), 1-cyano-2,4-cyclopentadiene + H (2.3-3.0%) and 1-ethynyl-pyrrole + H (0.4-0.6%), with the most favorable pathways being the initial adduct i1 leading to the formation of a seven-membered cyclic intermediate i12 through an exothermic ring expansion process and a multistep route i12 → i15 → i16 → C5H5 + HCN featuring an intramolecular ring-shrinking process involving a C-C bond fusion elimination channel to yield the bicyclic intermediate i15, followed by hydrogen cyanide elimination, thus forming a cyclopentadienyl radical. The calculated product branching ratios were consistent with the available experimental data; however, some quantitative deviations from the experimental results and the possible reasons are also discussed. The possible effects of the title reaction on the upper atmosphere of Titan, with critical implications for the rapid degradation of nitrogen-bearing polycyclic aromatic hydrocarbons, were compared with the mass growth processes of their polycyclic aromatic hydrocarbon counterparts produced through ring expansion.
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Affiliation(s)
- Chih-Hao Chin
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China.
| | - Tong Zhu
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China.
| | - John Zeng Hui Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, 200062, China. and Department of Chemistry, New York University, New York 10003, USA
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6
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Jian J, Wu X, Chen M, Zhou M. Boron-Mediated Carbon-Carbon Bond Cleavage and Rearrangement of Benzene Forming the Borepinyl Radical and Borole Derivatives. J Am Chem Soc 2020; 142:10079-10086. [PMID: 32383858 DOI: 10.1021/jacs.0c02131] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The reaction of atomic boron with benzene in solid neon has been investigated by matrix isolation infrared spectroscopy with isotopic substitutions as well as quantum chemical calculations. The reaction is initiated by boron atom addition to benzene in forming an η2-(1, 4) π adduct (A). A borepinyl radical (B) formed by C-C bond insertion is also observed on annealing. The η2-(1,4) π adduct photoisomerizes to an unprecedented borole substituted vinyl radical intermediate (C) via ring-opening and rearrangement reactions involving an antiaromatic borole subunit. A previously unconsidered 1-ethynyl-2-dihydro-1H-borole radical (D) is generated as the final product under UV light irradiation. The results presented herein give new insight into the benzene carbon-carbon bond cleavage and rearrangement reactions mediated by a nonmetal and provide a possible route for the construction of heterocyclic borepinyl and borole species via benzene ring opening and rearrangement reactions.
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Affiliation(s)
- Jiwen Jian
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, China
| | - Xuan Wu
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative materials, Fudan University, Shanghai 200433, China
| | - Mohua Chen
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative materials, Fudan University, Shanghai 200433, China
| | - Mingfei Zhou
- Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative materials, Fudan University, Shanghai 200433, China
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7
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Keshavarz F. Chemical Kinetics Approves the Occurrence of C ( 3P j) Reaction with H 2O. J Phys Chem A 2019; 123:5877-5892. [PMID: 31268710 DOI: 10.1021/acs.jpca.9b03492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although both atomic carbon and water are omnipresent in human life, there is a debate about the possibility of carbon reaction with water. Some low-temperature spectroscopic investigations have rejected the reaction, whereas some room-temperature experiments and theoretical studies have accepted the possibility of the reaction by reporting rate coefficients ranging from 105 to 109 L mol-1 s-1. This study provides new lines of evidence about the reaction through exploration of the reaction mechanism using the CCSD(T) method and solving the corresponding master equation by following two main approaches. According to the results, the rate coefficient of the reaction is significantly influenced by the tunneling and hindered rotation effects, in addition to the selected total angular momentum (J). Furthermore, the total rate coefficient of the reaction increases dramatically (from 107 to 1011 L mol-1 s-1) with the rise of temperature from 100 to 4000 K, while the total rate coefficient is insensitive to pressure (0.1-10 atm). Despite some differences between the results of the two approaches, the rate coefficients of both methods are consistent with the previously reported rate coefficients. Also, in agreement with the previous studies, the major products are 2HOC + 2H and 2HCO + 2H. In general, the findings approve the occurrence of the title reaction and indicate that the mentioned conflict is due to the sensitivity of the reaction to the investigated temperature and J level. The sensitivity does not permit low-temperature spectroscopic studies to detect any products and varies the measured and calculated rate coefficients.
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Affiliation(s)
- Fatemeh Keshavarz
- Department of Chemistry, College of Science , Shiraz University , Shiraz 71946-84795 , Iran
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8
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Lee KLK, McCarthy M. Study of Benzene Fragmentation, Isomerization, and Growth Using Microwave Spectroscopy. J Phys Chem Lett 2019; 10:2408-2413. [PMID: 31021635 DOI: 10.1021/acs.jpclett.9b00586] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Using a combination of broadband and cavity Fourier transform microwave spectroscopies, and newly developed analysis and assignment tools, the discharge products of benzene have been extensively studied in the 2-18 GHz frequency range. More than 450 spectral features with intensities greater than 6σ of the noise RMS were identified, of which of roughly four-fifths (82%) constituting 90% of the total spectral intensity were assigned to 38 species previously detected in the radio band, and nine entirely new hydrocarbon molecules were identified. The new species include both branched and chain fragments of benzene, high energy C6H6 isomers, and larger molecules such as phenyldiacetylene and isomers of fulvenallene; taken together they account for roughly half of the number of observed transitions and 51% of the spectral line intensity. Transitions from vibrationally excited states of several molecules were also identified in the course of this investigation. A key aspect of the present analysis was implementation of a rapid and efficient workflow to assign spectral features from known molecules and to identify line progressions by pattern recognition techniques.
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Affiliation(s)
- Kin Long Kelvin Lee
- Harvard-Smithsonian Center for Astrophysics , 60 Garden Street , Cambridge , Massachusetts 02138 , United States
| | - Michael McCarthy
- Harvard-Smithsonian Center for Astrophysics , 60 Garden Street , Cambridge , Massachusetts 02138 , United States
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9
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Brown AR, Brice JT, Franke PR, Douberly GE. Infrared Spectrum of Fulvenallene and Fulvenallenyl in Helium Droplets. J Phys Chem A 2019; 123:3782-3792. [DOI: 10.1021/acs.jpca.9b01661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alaina R. Brown
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Joseph T. Brice
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Peter R. Franke
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Gary E. Douberly
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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10
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Abplanalp MJ, Jones BM, Kaiser RI. Untangling the methane chemistry in interstellar and solar system ices toward ionizing radiation: a combined infrared and reflectron time-of-flight analysis. Phys Chem Chem Phys 2018; 20:5435-5468. [PMID: 28972622 DOI: 10.1039/c7cp05882a] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pure methane (CH4/CD4) ices were exposed to three ionizing radiation sources at 5.5 K under ultrahigh vacuum conditions to compare the complex hydrocarbon spectrum produced across several interstellar environments. These irradiation sources consisted of energetic electrons to simulate secondary electrons formed in the track of galactic cosmic rays (GCRs), Lyman α (10.2 eV; 121.6 nm) photons simulated the internal VUV field in a dense cloud, and broadband (112.7-169.8 nm; 11.0-7.3 eV) photons which mimic the interstellar ultra-violet field. The in situ chemical evolution of the ices was monitored via Fourier transform infrared spectroscopy (FTIR) and during heating via mass spectrometry utilizing a quadrupole mass spectrometer with an electron impact ionization source (EI-QMS) and a reflectron time-of-flight mass spectrometer with a photoionization source (PI-ReTOF-MS). The FTIR analysis detected six small hydrocarbon products from the three different irradiation sources: propane [C3H8(C3D8)], ethane [C2H6(C2D6)], the ethyl radical [C2H5(C2D5)], ethylene [C2H4(C2D4)], acetylene [C2H2(C2D2)], and the methyl radical [CH3(CD3)]. The sensitive PI-ReTOF-MS analysis identified a complex array of products with different products being detected between experiments with general formulae: CnH2n+2 (n = 4-8), CnH2n (n = 3-9), CnH2n-2 (n = 3-9), CnH2n-4 (n = 4-9), and CnH2n-6 (n = 6-7) from electron irradiation and CnH2n+2 (n = 4-8), CnH2n (n = 3-10), CnH2n-2 (n = 3-11), CnH2n-4 (n = 4-11), CnH2n-6 (n = 5-11), and CnH2n-8 (n = 6-11) from broadband photolysis and Lyman α photolysis. These experiments show that even the simplest hydrocarbon can produce important complex hydrocarbons such as C3H4 and C4H6 isomers. Distinct isomers from these groups have been shown to be important reactants in the synthesis of polycyclic aromatic hydrocarbons like indene (C9H8) and naphthalene (C10H8) under interstellar conditions.
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Affiliation(s)
- Matthew J Abplanalp
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822, USA.
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Reilly NJ, da Silva G, Wilcox CM, Ge Z, Kokkin DL, Troy TP, Nauta K, Kable SH, McCarthy MC, Schmidt TW. Interconversion of Methyltropyl and Xylyl Radicals: A Pathway Unavailable to the Benzyl–Tropyl Rearrangement. J Phys Chem A 2018; 122:1261-1269. [DOI: 10.1021/acs.jpca.7b11914] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Neil J. Reilly
- Department
of Chemistry, University of Massachusetts Boston, 100 Morrissey
Boulevard, Boston, Massachusetts 02125, United States
| | - Gabriel da Silva
- Department
of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Callan M. Wilcox
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Zijun Ge
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Damian L. Kokkin
- Department
of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201-1881, United States
| | - Tyler P. Troy
- Advanced
Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Klaas Nauta
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Scott H. Kable
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Michael C. McCarthy
- Harvard−Smithsonian
Center for Astrophysics and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Timothy W. Schmidt
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
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12
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Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane Qld 4072 Australien
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13
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Wentrup C. Flash Vacuum Pyrolysis: Techniques and Reactions. Angew Chem Int Ed Engl 2017; 56:14808-14835. [PMID: 28675675 DOI: 10.1002/anie.201705118] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Indexed: 12/13/2022]
Abstract
Flash vacuum pyrolysis (FVP) had its beginnings in the 1940s and 1950s, mainly through mass spectrometric detection of pyrolytically formed free radicals. In the 1960s many organic chemists started performing FVP experiments with the purpose of isolating new and interesting compounds and understanding pyrolysis processes. Meanwhile, many different types of apparatus and techniques have been developed, and it is the purpose of this review to present the most important methods as well as a survey of typical reactions and observations that can be achieved with the various techniques. This includes preparative FVP, chemical trapping reactions, matrix isolation, and low temperature spectroscopy of reactive intermediates and unstable molecules, the use of online mass, photoelectron, microwave, and millimeterwave spectroscopies, gas-phase laser pyrolysis, pulsed pyrolysis with supersonic jet expansion, very low pressure pyrolysis for kinetic investigations, solution-spray and falling-solid FVP for involatile compounds, and pyrolysis over solid supports and reagents. Moreover, the combination of FVP with matrix isolation and photochemistry is a powerful tool for investigations of reaction mechanism.
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Affiliation(s)
- Curt Wentrup
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld, 4072, Australia
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14
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Ramphal IA, Shapero M, Haibach-Morris C, Neumark DM. Photodissociation dynamics of fulvenallene and the fulvenallenyl radical at 248 and 193 nm. Phys Chem Chem Phys 2017; 19:29305-29314. [DOI: 10.1039/c7cp05490d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photofragment translational spectroscopy was used to study the photodissociation of fulvenallene, C7H6, and the fulvenallenyl radical, C7H5. Fulvenallene only loses H atoms to form fulvenallenyl. Fulvenallenyl exhibits both C2H2-loss and C3H3-loss pathways.
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Affiliation(s)
- Isaac A. Ramphal
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
| | - Mark Shapero
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
| | | | - Daniel M. Neumark
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
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15
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16
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Thapa J, Spencer M, Akhmedov NG, Goulay F. Kinetics of the OH Radical Reaction with Fulvenallene from 298 to 450 K. J Phys Chem Lett 2015; 6:4997-5001. [PMID: 26625195 DOI: 10.1021/acs.jpclett.5b02417] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Self-recombination and cross-reactions of large resonant stabilized hydrocarbon radicals such as fulvenallenyl (C7H5) are predicted to form polycyclic aromatic hydrocarbons in combustion and the interstellar medium. Although fulvenallenyl is likely to be present in these environments, large uncertainties remain about its formation mechanisms. We have investigated the formation of fulvenallenyl by reacting the OH radical with fulvenallene (C7H6) over the 298 to 450 K temperature range and at a pressure of 5 Torr (667 Pa). The reaction rate coefficient is found to be 8.8(±1.7) × 10(-12) cm(3) s(-1) at room temperature with a negative temperature dependence that can be fit from 298 to 450 K to k(T) = 8.8(±1.7) × 10(-12) (T/298 K)(-6.6(±1.1)) exp[-(8.72(±3.03) kJ mol(-1))/(R((1/T) - (1/298 K)))] cm(3) s(-1). The comparison of the experimental data with calculated abstraction rate coefficients suggests that over the experimental temperature range, association of the OH radical to fulvenallene plays a significant role likely leading to a low fulvenallenyl branching fraction.
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Affiliation(s)
- Juddha Thapa
- Department of Chemistry, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Michael Spencer
- Department of Chemistry, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Novruz G Akhmedov
- Department of Chemistry, West Virginia University , Morgantown, West Virginia 26506, United States
| | - Fabien Goulay
- Department of Chemistry, West Virginia University , Morgantown, West Virginia 26506, United States
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Abstract
The gas phase detection of benzocyclopropenyl is reported. In this aromatic resonance stabilized radical, a large angular strain is present due to a three-membered ring annelated to a benzene. The resonant two-color two-photon ionization technique is used to record the D1((2)A2) ← D0((2)B1) electronic transition of this radical after the in situ synthesis in a discharge source. The spectrum features absorptions up to 3300 cm(-1) above the origin band at 19,305 cm(-1). Benzocyclopropenyl is possibly the major product of the bimolecular reaction of benzene and an atomic carbon at low temperatures.
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Affiliation(s)
- Surajit Maity
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, CH 4056 Basel, Switzerland
| | - Mathias Steglich
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, CH 4056 Basel, Switzerland
| | - John P Maier
- Department of Chemistry, University of Basel , Klingelbergstrasse 80, CH 4056 Basel, Switzerland
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18
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Mebel AM, Kaiser RI. Formation of resonantly stabilised free radicals via the reactions of atomic carbon, dicarbon, and tricarbon with unsaturated hydrocarbons: theory and crossed molecular beams experiments. INT REV PHYS CHEM 2015. [DOI: 10.1080/0144235x.2015.1075280] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Alexander M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Ralf I. Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
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19
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Maranzana A, Tonachini G. Antagonistic Functionalized Nucleation and Oxidative Degradation in Combustive Formation of Pyrene-Based Clusters Mediated by Triplet O and O 2: Theoretical Study. Chemphyschem 2015; 16:2615-24. [DOI: 10.1002/cphc.201500332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Indexed: 11/11/2022]
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20
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Kvaskoff D, Lüerssen H, Bednarek P, Wentrup C. Phenylnitrene, Phenylcarbene, and Pyridylcarbenes. Rearrangements to Cyanocyclopentadiene and Fulvenallene. J Am Chem Soc 2014; 136:15203-14. [DOI: 10.1021/ja506151p] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David Kvaskoff
- School
of Chemistry and Molecular
Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Holger Lüerssen
- School
of Chemistry and Molecular
Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Pawel Bednarek
- School
of Chemistry and Molecular
Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Curt Wentrup
- School
of Chemistry and Molecular
Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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