1
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Matsugi A, Suzuki S. Ring Growth Mechanism in the Reaction between Fulvenallenyl and Cyclopentadienyl Radicals. J Phys Chem A 2024; 128:1327-1338. [PMID: 38351621 DOI: 10.1021/acs.jpca.3c07441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Recombination between resonance-stabilized hydrocarbon radicals is an important class of reactions that contribute to molecular growth chemistry in combustion. In the present study, the ring growth mechanism in the reaction between fulvenallenyl (C7H5) and cyclopentadienyl (C5H5) radicals is investigated computationally. The reaction pathways are explored by quantum chemical calculations, and the phenomenological and steady-state rate constants are determined by solving the multiple-well master equations. The primary reaction routes following the recombination between the two radicals are found to be as follows: formation of the adducts, isomerization by hydrogen shift reactions, cyclization to form tricyclic compounds, and their isomerization and dissociation reactions, leading to the formation of acenaphthylene. The overall process can be approximately represented as C7H5 + C5H5 → acenaphthylene + 2H with the bimolecular rate constant of about 4 × 10-12 cm3 molecule-1 s-1. A reaction mechanism consisting of 20 reactions, including the formation, isomerization, and dissociation processes of major intermediate species, is proposed for use in kinetic modeling.
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Affiliation(s)
- Akira Matsugi
- Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba 305-8569, Japan
| | - Shunsuke Suzuki
- Research Institute for Energy Conversion, National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba 305-8564, Japan
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2
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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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3
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Sundar SP, Al-Hammadi S, Ren Z, da Silva G. Thermal Decomposition Kinetics of the Indenyl Radical: A Theoretical Study. J Phys Chem A 2021; 125:2782-2790. [PMID: 33783215 DOI: 10.1021/acs.jpca.1c01000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Quantum chemistry and statistical reaction rate theory calculations have been performed to investigate the products and kinetics of indenyl radical decomposition. Three competitive product sets are identified, including formation of a cyclopentadienyl radical (c-C5H5) and diacetylene (C4H2), which has not been included in prior theoretical kinetics investigations. Rate coefficients for indenyl decomposition are determined from master equation simulations at 1800-2400 K and 0.01-100 atm, and temperature- and pressure-dependent rate coefficient expressions are incorporated into a detailed chemical kinetic model for indene pyrolysis. Indenyl is found to predominantly decompose to o-benzyne (o-C6H4) + propargyl (C3H3), with lesser amounts of fulvenallenyl (C7H5) + C2H2 and c-C5H5 + C4H2.
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Affiliation(s)
- Srivathsan P Sundar
- Department of Chemical Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Saddam Al-Hammadi
- Department of Chemical Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Zhonghua Ren
- Department of Chemical Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Gabriel da Silva
- Department of Chemical Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
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4
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Sullivan EN, Nichols B, von Kugelgen S, da Silva G, Neumark DM. Multiphoton dissociation dynamics of the indenyl radical at 248 nm and 193 nm. J Chem Phys 2019; 151:174303. [PMID: 31703498 PMCID: PMC7043848 DOI: 10.1063/1.5121294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/10/2019] [Indexed: 11/14/2022] Open
Abstract
Photofragment translational spectroscopy is used to investigate the unimolecular photodissociation of the indenyl radical (C9H7). C9H7 radicals are generated by photodetachment of C9H7 - anions and are dissociated at 248 nm (5.00 eV) and 193 nm (6.42 eV). The following product channels are definitively observed at both wavelengths: C2H2 + C7H5, C2H2 + C3H3 + C4H2, and C2H2 + C2H2 + C5H3. The three-body product channels are energetically inaccessible from single photon excitation at either dissociation wavelength. This observation, in combination with calculated dissociation rates and laser power studies, implies that all dissociation seen in this experiment occurs exclusively through multiphoton processes in which the initial C9H7 radical absorbs two photons sequentially prior to dissociation to two or three fragments. The corresponding translational energy distributions for each product channel peak well below the maximum available energy for two photons and exhibit similar behavior regardless of dissociation wavelength. These results suggest that all products are formed by internal conversion to the ground electronic state, followed by dissociation.
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Affiliation(s)
- Erin N. Sullivan
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Bethan Nichols
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Stephen von Kugelgen
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Gabriel da Silva
- Department of Chemical Engineering, University of Melbourne, Victoria 3010 Australia
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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5
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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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6
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Thomas AM, Lucas M, Zhao L, Liddiard J, Kaiser RI, Mebel AM. A combined crossed molecular beams and computational study on the formation of distinct resonantly stabilized C 5H 3 radicals via chemically activated C 5H 4 and C 6H 6 intermediates. Phys Chem Chem Phys 2018. [PMID: 29537029 DOI: 10.1039/c8cp00357b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The crossed molecular beams technique was utilized to explore the formation of three isomers of resonantly stabilized (C5H3) radicals along with their d2-substituted counterparts via the bimolecular reactions of singlet/triplet dicarbon [C2(X1Σ+g/a3Πu)] with methylacetylene [CH3CCH(X1A1)], d3-methylacetylene [CD3CCH(X1A1)], and 1-butyne [C2H5CCH(X1A')] at collision energies up to 26 kJ mol-1via chemically activated singlet/triplet C5H4/C5D3H and C6H6 intermediates. These studies exploit a newly developed supersonic dicarbon [C2(X1Σ+g/a3Πu)] beam generated via photolysis of tetrachloroethylene [C2Cl4(X1Ag)] by excluding interference from carbon atoms, which represent the dominating (interfering) species in ablation-based dicarbon sources. We evaluated the performance of the dicarbon [C2(X1Σ+g/a3Πu)] beam in reactions with methylacetylene [CH3CCH(X1A1)] and d3-methylacetylene [CD3CCH(X1A1)]; the investigations demonstrate that the reaction dynamics match previous studies in our laboratory utilizing ablation-based dicarbon sources involving the synthesis of 1,4-pentadiynyl-3 [HCCCHCCH(X2B1)] and 2,4-pentadiynyl-1 [H2CCCCCH(X2B1)] radicals via hydrogen (deuterium) atom elimination. Considering the C2(X1Σ+g/a3Πu)-1-butyne [C2H5CCH(X1A')] reaction, the hitherto elusive methyl-loss pathway was detected. This channel forms the previously unknown resonantly stabilized penta-1-yn-3,4-dienyl-1 [H2CCCHCC(X2A)] radical along with the methyl radical [CH3(X2A2'')] and is open exclusively on the triplet surface with an overall reaction energy of -86 ± 10 kJ mol-1. The preferred reaction pathways proceed first by barrierless addition of triplet dicarbon to the π-electronic system of 1-butyne, either to both acetylenic carbon atoms or to the sterically more accessible carbon atom, to form the methyl-bearing triplet C6H6 intermediates [i41b] and [i81b], respectively, with the latter decomposing via a tight exit transition state to penta-1-yn-3,4-dienyl-1 [(H2CCCHCC(X2A)] plus the methyl radical [CH3(X2A2'')]. The successful unraveling of this methyl-loss channel - through collaborative experimental and computational efforts - underscores the viability of the photolytically generated dicarbon beam as an unprecedented tool to access reaction dynamics underlying the formation of resonantly stabilized free radicals (RSFR) that are vital to molecular mass growth processes that ultimately lead to polycyclic aromatic hydrocarbons (PAHs).
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Affiliation(s)
- Aaron M Thomas
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
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7
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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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8
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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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9
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Chakraborty A, Fulara J, Maier JP. The Electronic Spectrum of the Fulvenallenyl Radical. Angew Chem Int Ed Engl 2015; 55:228-31. [DOI: 10.1002/anie.201508961] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Indexed: 11/09/2022]
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10
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Chakraborty A, Fulara J, Maier JP. The Electronic Spectrum of the Fulvenallenyl Radical. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201508961] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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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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12
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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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13
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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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14
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Fulara J, Chakraborty A, Nagy A, Filipkowski K, Maier JP. Electronic transitions of C₅H₃⁺ and C₅H₃: neon matrix and CASPT2 studies. J Phys Chem A 2015; 119:2338-43. [PMID: 25180760 DOI: 10.1021/jp506706f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two absorption systems of C5H3(+) starting at 350 and 345 nm were detected following mass-selective deposition of m/e = 63 ions in a 6 K neon matrix. These are assigned to the 1 (1)A1 ← X (1)A1 electronic transition of 1,2,3,4-pentatetraenylium H2CCCCCH(+) (isomer B(+)) and 1 (1)B2 ← X (1)A1 of penta-1,4-diyne-3-ylium HCCCHCCH(+) (C(+)). The absorptions of neutral C5H3 isomers with onsets at 434.5, 398.3, 369.0, and 267.3 nm are also detected. The first two systems are assigned to the 1 (2)B1 ← X (2)B1 and 1 (2)A2 ← X (2)B1 transitions of isomer B and C, respectively, and the latter two to ethynylcyclopropenyl (A) and 3-vinylidenecycloprop-1-enyl (D) radicals. The structural assignments are based on the adiabatic excitation energies calculated with the MS-CASPT2 method. A vibrational analysis of the electronic spectra, based on the calculated harmonic frequencies, supports this.
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Affiliation(s)
- Jan Fulara
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Arghya Chakraborty
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Adam Nagy
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Karol Filipkowski
- 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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15
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Karton A, Goerigk L. Accurate reaction barrier heights of pericyclic reactions: Surprisingly large deviations for the CBS-QB3 composite method and their consequences in DFT benchmark studies. J Comput Chem 2015; 36:622-32. [DOI: 10.1002/jcc.23837] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/17/2014] [Accepted: 12/21/2014] [Indexed: 01/18/2023]
Affiliation(s)
- Amir Karton
- School of Chemistry and Biochemistry; The University of Western Australia; Perth WA 6009 Australia
| | - Lars Goerigk
- School of Chemistry; The University of Melbourne; Parkville VIC 3010 Australia
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16
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Buckingham GT, Ormond TK, Porterfield JP, Hemberger P, Kostko O, Ahmed M, Robichaud DJ, Nimlos MR, Daily JW, Ellison GB. The thermal decomposition of the benzyl radical in a heated micro-reactor. I. Experimental findings. J Chem Phys 2015; 142:044307. [DOI: 10.1063/1.4906156] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Grant T. Buckingham
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, USA
| | - Thomas K. Ormond
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, USA
| | - Jessica P. Porterfield
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
| | - Patrick Hemberger
- Molecular Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen-PSI, Switzerland
| | - Oleg Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, USA
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, USA
| | - David J. Robichaud
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, USA
| | - Mark R. Nimlos
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, USA
| | - John W. Daily
- Department of Mechanical Engineering, Center for Combustion and Environmental Research,University of Colorado, Boulder, Colorado 80309-0427, USA
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
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17
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Somers KP, Simmie JM, Metcalfe WK, Curran HJ. The pyrolysis of 2-methylfuran: a quantum chemical, statistical rate theory and kinetic modelling study. Phys Chem Chem Phys 2014; 16:5349-67. [PMID: 24496403 DOI: 10.1039/c3cp54915a] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Due to the rapidly growing interest in the use of biomass derived furanic compounds as potential platform chemicals and fossil fuel replacements, there is a simultaneous need to understand the pyrolysis and combustion properties of such molecules. To this end, the potential energy surfaces for the pyrolysis relevant reactions of the biofuel candidate 2-methylfuran have been characterized using quantum chemical methods (CBS-QB3, CBS-APNO and G3). Canonical transition state theory is employed to determine the high-pressure limiting kinetics, k(T), of elementary reactions. Rice-Ramsperger-Kassel-Marcus theory with an energy grained master equation is used to compute pressure-dependent rate constants, k(T,p), and product branching fractions for the multiple-well, multiple-channel reaction pathways which typify the pyrolysis reactions of the title species. The unimolecular decomposition of 2-methylfuran is shown to proceed via hydrogen atom transfer reactions through singlet carbene intermediates which readily undergo ring opening to form collisionally stabilised acyclic C5H6O isomers before further decomposition to C1-C4 species. Rate constants for abstraction by the hydrogen atom and methyl radical are reported, with abstraction from the alkyl side chain calculated to dominate. The fate of the primary abstraction product, 2-furanylmethyl radical, is shown to be thermal decomposition to the n-butadienyl radical and carbon monoxide through a series of ring opening and hydrogen atom transfer reactions. The dominant bimolecular products of hydrogen atom addition reactions are found to be furan and methyl radical, 1-butene-1-yl radical and carbon monoxide and vinyl ketene and methyl radical. A kinetic mechanism is assembled with computer simulations in good agreement with shock tube speciation profiles taken from the literature. The kinetic mechanism developed herein can be used in future chemical kinetic modelling studies on the pyrolysis and oxidation of 2-methylfuran, or the larger molecular structures for which it is a known pyrolysis/combustion intermediate (e.g. cellulose, coals, 2,5-dimethylfuran).
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Affiliation(s)
- Kieran P Somers
- Combustion Chemistry Centre, National University of Ireland, Galway, Republic of Ireland.
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18
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da Silva G. Reaction of Benzene with Atomic Carbon: Pathways to Fulvenallene and the Fulvenallenyl Radical in Extraterrestrial Atmospheres and the Interstellar Medium. J Phys Chem A 2014; 118:3967-72. [DOI: 10.1021/jp503431a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gabriel da Silva
- Department
of Chemical and
Biomolecular Engineering, The University of Melbourne, Victoria 3010, Australia
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19
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Trogolo D, Maranzana A, Ghigo G, Tonachini G. First Ring Formation by Radical Addition of Propargyl to But-1-ene-3-yne in Combustion. Theoretical Study of the C7H7 Radical System. J Phys Chem A 2014; 118:427-40. [DOI: 10.1021/jp4082905] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniela Trogolo
- Dipartimento di Chimica, Università di Torino, Corso Massimo
D’Azeglio 48, I-10125 Torino, Italy
| | - Andrea Maranzana
- Dipartimento di Chimica, Università di Torino, Corso Massimo
D’Azeglio 48, I-10125 Torino, Italy
| | - Giovanni Ghigo
- Dipartimento di Chimica, Università di Torino, Corso Massimo
D’Azeglio 48, I-10125 Torino, Italy
| | - Glauco Tonachini
- Dipartimento di Chimica, Università di Torino, Corso Massimo
D’Azeglio 48, I-10125 Torino, Italy
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20
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Chakraborty A, Fulara J, Dietsche R, Maier JP. Spectroscopic characterization of C7H3+ and C7H3˙: electronic absorption and fluorescence in 6 K neon matrices. Phys Chem Chem Phys 2014; 16:7023-30. [DOI: 10.1039/c4cp00043a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electronic absorption spectra of mass-selected C7H3+ and C7H3˙ isomers in a neon matrix have been identified for the first time.
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Affiliation(s)
- Arghya Chakraborty
- Department of Chemistry, University of Basel, Klingelbergstarasse 80, CH-4056, Basel, Switzerland.
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21
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Pinches SJ, da Silva G. On the Separation of Timescales in Chemically Activated Reactions. INT J CHEM KINET 2013. [DOI: 10.1002/kin.20774] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Samuel J. Pinches
- Department of Chemical and Biomolecular Engineering; The University of Melbourne; Victoria 3010 Australia
| | - Gabriel da Silva
- Department of Chemical and Biomolecular Engineering; The University of Melbourne; Victoria 3010 Australia
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23
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Giegerich J, Fischer I. Photodissociation dynamics of fulvenallene, C7H6. Phys Chem Chem Phys 2013; 15:13162-8. [DOI: 10.1039/c3cp52274a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Chalyavi N, Troy TP, Bacskay GB, Nauta K, Kable SH, Reid SA, Schmidt TW. Excitation spectra of the jet-cooled 4-phenylbenzyl and 4-(4'-methylphenyl)benzyl radicals. J Phys Chem A 2012; 116:10780-5. [PMID: 23082991 DOI: 10.1021/jp309003u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The excitation spectra of jet-cooled 4-phenylbenzyl and 4-(4'-methylphenyl)benzyl radicals have been identified by a combination of resonant two-color two-photon ionization mass spectrometry and quantum chemical methods. Both radicals exhibit progressions in the biphenyl torsional mode, peaking near ν = 17. The lowest observed peak for 4-phenylbenzyl was observed at 18598 cm(-1) and is estimated to be the ν = 3 of the progression, while the lowest observed peak for the 4-(4'-methylphenyl)benzyl radical was observed at 18183 cm(-1) and is possibly the origin. The spectra are discussed and compared to other biphenyl and benzyl chromophores.
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Affiliation(s)
- Nahid Chalyavi
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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da Silva G, Trevitt AJ, Steinbauer M, Hemberger P. Pyrolysis of fulvenallene (C7H6) and fulvenallenyl (C7H5): Theoretical kinetics and experimental product detection. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.10.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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Derudi M, Polino D, Cavallotti C. Toluene and benzyl decomposition mechanisms: elementary reactions and kinetic simulations. Phys Chem Chem Phys 2011; 13:21308-18. [DOI: 10.1039/c1cp22601k] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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