51
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Pan Y, Hu Y, Wang J, Ye L, Liu C, Zhu Z. Online Characterization of Isomeric/Isobaric Components in the Gas Phase of Mainstream Cigarette Smoke by Tunable Synchrotron Radiation Vacuum Ultraviolet Photoionization Time-of-Flight Mass Spectrometry and Photoionization Efficiency Curve Simulation. Anal Chem 2013; 85:11993-2001. [DOI: 10.1021/ac402955k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yang Pan
- National
Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
| | - Yonghua Hu
- Center
of Technology, China Tobacco
Anhui Industrial Co, Ltd., Hefei, Anhui 230088, P. R. China
| | - Jian Wang
- National
Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
| | - Lili Ye
- National
Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
| | - Chengyuan Liu
- National
Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
| | - Zhixiang Zhu
- National
Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
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52
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Dangi BB, Maity S, Kaiser RI, Mebel AM. A Combined Crossed Beam and Ab Initio Investigation of the Gas Phase Reaction of Dicarbon Molecules (C2; X1Σg+/a3Πu) with Propene (C3H6; X1A′): Identification of the Resonantly Stabilized Free Radicals 1- and 3-Vinylpropargyl. J Phys Chem A 2013; 117:11783-93. [DOI: 10.1021/jp402700j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Beni B. Dangi
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United
States
| | - Surajit Maity
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United
States
| | - Ralf I. Kaiser
- Department of Chemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United
States
| | - Alexander M. Mebel
- Department of Chemistry
and Biochemistry, Florida International University, Miami, Florida 33199, United States
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53
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Poveda J, Álvarez I, Cisneros C. Excitation energies and multiphoton dissociation–ionization of 1,4-pentadiene at 266 and 355 nm. Mol Phys 2012. [DOI: 10.1080/00268976.2012.699107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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54
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Sério S, Nunes Y, Hoffmann SV, Mason NJ, Duflot D, Limão-Vieira P. Electronic State Spectroscopy of 1,4-Pentadiene As Studied by VUV Photoabsorption Spectroscopy and ab Initio Calculations. J Phys Chem A 2012; 116:8176-84. [DOI: 10.1021/jp305905j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- S. Sério
- Laboratório
de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências
e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Y. Nunes
- Laboratório
de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências
e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - S. V. Hoffmann
- Institute for Storage Ring Facilities, Aarhus University, Ny Munkegade, DK-8000, Århus C, Denmark
| | - N. J. Mason
- Centre of Earth, Planetary, Space and Astronomy
Research, Department of Physics and Astronomy, The Open University, Walton Hall, Milton
Keynes MK7 6AA, U.K
| | - D. Duflot
- Laboratoire
de Physique des Lasers, Atomes et Molécules (PhLAM), UMR CNRS
8523, Université Lille 1, F-59655
Villeneuve d’Ascq Cedex, France
| | - P. Limão-Vieira
- Laboratório
de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências
e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
- Centre of Earth, Planetary, Space and Astronomy
Research, Department of Physics and Astronomy, The Open University, Walton Hall, Milton
Keynes MK7 6AA, U.K
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55
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Kaiser RI, Goswami M, Maksyutenko P, Zhang F, Kim YS, Landera A, Mebel AM. A Crossed Molecular Beams and Ab Initio Study on the Formation of C6H3 Radicals. An Interface between Resonantly Stabilized and Aromatic Radicals. J Phys Chem A 2011; 115:10251-8. [DOI: 10.1021/jp205795h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. I. Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - M. Goswami
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - P. Maksyutenko
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - F. Zhang
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Y. S. Kim
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Alexander Landera
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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56
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Parker DSN, Zhang F, Kim YS, Kaiser RI, Mebel AM. On the formation of resonantly stabilized C5H3 radicals--a crossed beam and ab initio study of the reaction of ground state carbon atoms with vinylacetylene. J Phys Chem A 2011; 115:593-601. [PMID: 21194192 DOI: 10.1021/jp109800h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The formation of polycyclic aromatic hydrocarbons in combustion environments is linked to resonance stabilized free radicals. Here, we investigated the reaction dynamics of ground state carbon atoms, C((3)P(j)), with vinylacetylene at two collision energies of 18.8 kJ mol(-1) and 26.4 kJ mol(-1) employing the crossed molecular beam technique leading to two resonantly stabilized free radicals. The reaction was found to be governed by indirect scattering dynamics and to proceed without an entrance barrier through a long-lived collision complex to reach the products, n- and i-C(5)H(3) isomers via tight exit transition states. The reaction pathway taken is dependent on whether the carbon atom attacks the π electron density of the double or triple bond, both routes have been compared to the reactions of atomic carbon with ethylene and acetylene. Electronic structure/statistical theory calculations determined the product branching ratio to be 2:3 between the n- and i-C(5)H(3) isomers.
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Affiliation(s)
- Dorian S N Parker
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii, USA
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57
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da Silva G, Trevitt AJ. Chemically activated reactions on the C7H5 energy surface: propargyl + diacetylene, i-C5H3 + acetylene, and n-C5H3 + acetylene. Phys Chem Chem Phys 2011; 13:8940-52. [DOI: 10.1039/c1cp20112c] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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58
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Goulay F, Soorkia S, Meloni G, Osborn DL, Taatjes CA, Leone SR. Detection of pentatetraene by reaction of the ethynyl radical (C2H) with allene (CH2CCH2) at room temperature. Phys Chem Chem Phys 2011; 13:20820-7. [DOI: 10.1039/c1cp22609f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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59
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Soorkia S, Trevitt AJ, Selby TM, Osborn DL, Taatjes CA, Wilson KR, Leone SR. Reaction of the C2H Radical with 1-Butyne (C4H6): Low-Temperature Kinetics and Isomer-Specific Product Detection. J Phys Chem A 2010; 114:3340-54. [DOI: 10.1021/jp911132r] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Satchin Soorkia
- Departments of Chemistry and Physics, University of California, Berkeley, California 94720
| | - Adam J. Trevitt
- School of Chemistry, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Talitha M. Selby
- Department of Chemistry, University of Wisconsin—Washington County, West Bend, Wisconsin 53095
| | - David L. Osborn
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969
| | - Craig A. Taatjes
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969
| | - Kevin R. Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Stephen R. Leone
- Departments of Chemistry and Physics, University of California, Berkeley, California 94720 and Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
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60
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Reilly NJ, Nakajima M, Troy TP, Chalyavi N, Duncan KA, Nauta K, Kable SH, Schmidt TW. Spectroscopic Identification of the Resonance-Stabilized cis- and trans-1-Vinylpropargyl Radicals. J Am Chem Soc 2009; 131:13423-9. [DOI: 10.1021/ja904521c] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Neil J. Reilly
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | | | - Tyler P. Troy
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Nahid Chalyavi
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Kieran A. Duncan
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Klaas Nauta
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Scott H. Kable
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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61
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Mebel AM, Kislov VV. Can the C5H5 + C5H5 → C10H10 → C10H9 + H/C10H8 + H2 Reaction Produce Naphthalene? An Ab Initio/RRKM Study. J Phys Chem A 2009; 113:9825-33. [DOI: 10.1021/jp905931j] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- A. M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199
| | - V. V. Kislov
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199
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62
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Zhang F, Kim YS, Zhou L, Chang AHH, Kaiser RI. A crossed molecular beam study on the synthesis of the interstellar 2,4-pentadiynylidyne radical (HCCCCC). J Chem Phys 2009; 129:134313. [PMID: 19045096 DOI: 10.1063/1.2987366] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Crossed molecular beam experiments are performed to elucidate the synthesis of the 2,4-penta-diynylidyne [HCCCCC(X (2)Pi)] radical under single collision conditions--a crucial reaction intermediate to form polycyclic aromatic hydrocarbons and carbonaceous nanostructures in the interstellar medium and in combustion flames. The experiments demonstrate that the chemical dynamics of ground state carbon reacting with diacetylene [HCCCCH(X (1)Sigma(g)(+))] are indirect and proceed via addition of the electrophilic carbon atom to the pi electron density of the diacetylene molecule yielding ultimately the carbenelike HCCCCCH(X (3)Sigma(g)(-)) molecule. This intermediate fragments via hydrogen atom emission to yield the 2,4-pentadiynylidyne [HCCCCC(X (2)Pi)] radical. The chemical dynamics elucidated also allows us to predict that reaction of carbon atoms with polyynes of the generic formula H(C[triple bond]C)(n)H leads to the formation of hydrogen-terminated carbon clusters of the generic form HC(2n+1) in extreme environments. The acetylene-related reactivity and electronic structure of the diacetylene molecule also allow us to project that reactions of the diacetylene molecule with cyano and ethynyl radicals result in a stepwise extension of the carbon skeleton forming cyanodiacetylene (HCCCCCN) and triacetylene (HCCCCCCH) plus atomic hydrogen. These predictions open the door to extensive laboratory studies involving hitherto poorly understood reactions of the diacetylene molecule under single collision conditions.
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Affiliation(s)
- Fangtong Zhang
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
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63
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Meloni G, Selby TM, Osborn DL, Taatjes CA. Enol Formation and Ring-Opening in OH-Initiated Oxidation of Cycloalkenes. J Phys Chem A 2008; 112:13444-51. [DOI: 10.1021/jp808015f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Giovanni Meloni
- Department of Chemistry, University of San Francisco, San Francisco, California 94117
| | - Talitha M. Selby
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969
| | - David L. Osborn
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969
| | - Craig A. Taatjes
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969
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64
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Wang J, Struckmeier U, Yang B, Cool TA, Osswald P, Kohse-Höinghaus K, Kasper T, Hansen N, Westmoreland PR. Isomer-Specific Influences on the Composition of Reaction Intermediates in Dimethyl Ether/Propene and Ethanol/Propene Flame. J Phys Chem A 2008; 112:9255-65. [DOI: 10.1021/jp8011188] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juan Wang
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Ulf Struckmeier
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Bin Yang
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Terrill A. Cool
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Patrick Osswald
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Katharina Kohse-Höinghaus
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Tina Kasper
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Nils Hansen
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Phillip R. Westmoreland
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, Department of Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany, Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, and Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003
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65
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Gu X, Kaiser RI, Mebel AM. Chemistry of energetically activated cumulenes - from allene (H2CCCH2) to hexapentaene (H2CCCCCCH2). Chemphyschem 2008; 9:350-69. [PMID: 18275046 DOI: 10.1002/cphc.200700609] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
During the last decade, experimental and theoretical studies on the unimolecular decomposition of cumulenes (H(2)C(n)H(2)) from propadiene (H(2)CCCH(2)) to hexapentaene (H(2)CCCCCCH(2)) have received considerable attention due to the importance of these carbon-bearing molecules in combustion flames, chemical vapor deposition processes, atmospheric chemistry, and the chemistry of the interstellar medium. Cumulenes and their substituted counterparts also have significant technical potential as elements for molecular machines (nanomechanics), molecular wires (nano-electronics), nonlinear optics, and molecular sensors. In this review, we present a systematic overview of the stability, formation, and unimolecular decomposition of chemically, photo-chemically, and thermally activated small to medium-sized cumulenes in extreme environments. By concentrating on reactions under gas phase thermal conditions (pyrolysis) and on molecular beam experiments conducted under single-collision conditions (crossed beam and photodissociation studies), a comprehensive picture on the unimolecular decomposition dynamics of cumulenes transpires.
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Affiliation(s)
- Xibin Gu
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822, USA
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66
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Hansen N, Klippenstein SJ, Westmoreland PR, Kasper T, Kohse-Höinghaus K, Wang J, Cool TA. A combined ab initio and photoionization mass spectrometric study of polyynes in fuel-rich flames. Phys Chem Chem Phys 2008; 10:366-74. [DOI: 10.1039/b711578d] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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67
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Taatjes CA, Hansen N, Osborn DL, Kohse-Höinghaus K, Cool TA, Westmoreland PR. “Imaging” combustion chemistry via multiplexed synchrotron-photoionization mass spectrometry. Phys Chem Chem Phys 2008; 10:20-34. [DOI: 10.1039/b713460f] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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68
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Burcat A. Ab initio calculations of carbon-containing species and comparison with group additivity results: Part I. C5
species. INT J CHEM KINET 2007. [DOI: 10.1002/kin.20277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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69
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Kislov VV, Mebel AM. The Formation of Naphthalene, Azulene, and Fulvalene from Cyclic C5 Species in Combustion: An Ab Initio/RRKM Study of 9-H-Fulvalenyl (C5H5−C5H4) Radical Rearrangements. J Phys Chem A 2007; 111:9532-43. [PMID: 17711267 DOI: 10.1021/jp0732099] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chemically accurate ab initio Gaussian-3-type calculations of the C(10)H(9) potential energy surface (PES) for rearrangements of the 9-H-fulvalenyl radical C(5)H(5)-C(5)H(4) have been performed to investigate the formation mechanisms of polycyclic aromatic hydrocarbons (PAHs) originated from the recombination of two cyclopentadienyl radicals (c-C(5)H(5)) as well as from the intermolecular addition of cyclopentadienyl to cyclopentadiene (c-C(5)H(6)) under combustion and pyrolytic conditions. Statistical theory calculations have been applied to obtain high-pressure-limit thermal rate constants, followed by solving kinetic equations to evaluate relative product yields. At the high-pressure limit, naphthalene, fulvalene, and azulene have been shown as the reaction products in rearrangements of the 9-H-fulvalenyl radical, with relative yields depending on temperature. At low temperatures (T < 1000 K), naphthalene is predicted to be the major product (>50%), whereas at higher temperatures the naphthalene yield rapidly decreases and the formation of fulvalene becomes dominant. At T > 1500 K, naphthalene and azulene are only minor products accounting for less than 10% of the total yield. The reactions involving cyclopentadienyl radicals and cyclopentadiene have thus been shown to give only a small contribution to the naphthalene production on the C(10)H(9) PES at medium and high combustion temperatures. The high yields of fulvalene at these conditions indicate that cyclopentadienyl radical and cyclopentadiene more likely represent significant sources of cyclopentafused PAHs, which are possible fullerene precursors. Our results agree well with a low-temperature cyclopentadiene pyrolysis data, where naphthalene has been identified as the major reaction product together with indene. Azulene has been found to be only a minor product in 9-H-fulvalenyl radical rearrangements, with branching ratios of less than 5% at all studied temperatures. The production of naphthalene at low combustion temperatures (T < 1000 K) is governed by the spiran mechanism originally suggested by Melius et al. At higher temperatures, the alternative C-C bond scission route, which proceeds via the formation of the cis-4-phenylbutadienyl radical, is competitive with the spiran pathway. The contributions of the previously suggested methylene walk pathway to the production of naphthalene have been calculated to be negligible at all studied temperatures.
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Affiliation(s)
- V V Kislov
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA
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70
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Harding LB, Klippenstein SJ, Georgievskii Y. On the Combination Reactions of Hydrogen Atoms with Resonance-Stabilized Hydrocarbon Radicals. J Phys Chem A 2007; 111:3789-801. [PMID: 17388384 DOI: 10.1021/jp0682309] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Procedures for accurately predicting the kinetics of H atom associations with resonance stabilized hydrocarbon radicals are described and applied to a series of reactions. The approach is based on direct CASPT2/cc-pvdz evaluations of the orientation dependent interaction energies within variable reaction coordinate transition state theory. One-dimensional corrections to the interaction energies are estimated from a CASPT2/aug-cc-pvdz minimum energy path (MEP) on the specific reaction of interest and a CASPT2/aug-cc-pvtz MEP for the H + CH3 reaction. A dynamical correction factor of 0.9 is also applied. For the H + propargyl, allyl, cyclopentadienyl, and benzyl reactions, where the experimental values appear to be quite well determined, theory and experiment agree to within their error bars. Predictions are also made for the combinations with triplet propargylene, CH2CCCH, CH3CCCH2, CH2CHCCH2, CH3CHCCH, cyclic-C4H5, CH2CCCCH, and CHCCHCCH.
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Affiliation(s)
- Lawrence B Harding
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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71
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Hansen N, Kasper T, Klippenstein SJ, Westmoreland PR, Law ME, Taatjes CA, Kohse-Höinghaus K, Wang J, Cool TA. Initial Steps of Aromatic Ring Formation in a Laminar Premixed Fuel-Rich Cyclopentene Flame†. J Phys Chem A 2007; 111:4081-92. [PMID: 17300183 DOI: 10.1021/jp0683317] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A fuel-rich, nonsooting, premixed laminar cyclopentene flame (phi = 2.0) at 37.6 Torr (50 mbar) is investigated by flame-sampling photoionization molecular-beam mass spectrometry utilizing vacuum-ultraviolet synchrotron radiation. Mole fractions as a function of distance from the burner are measured for 49 intermediates with ion masses ranging from 2 (H2) to 106 (C8H10), providing a broad database for flame modeling studies. The isomeric composition is resolved for most species, and the identification of several C4Hx, C7H6, and C7H8 isomers is discussed in detail. The presence of C5H5CCH/C5H4CCH2 and cycloheptatriene is revealed by comparisons between flame-sampled photoionization efficiency data and theoretical simulations, based on calculated ionization energies and Franck-Condon factors. This insight suggests a new potential molecular- weight growth mechanism that is characterized by C5-C7 ring enlargement reactions.
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Affiliation(s)
- N Hansen
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
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72
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Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:127-38. [PMID: 17199253 PMCID: PMC7166443 DOI: 10.1002/jms.1070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (6 Weeks journals ‐ Search completed at 4th. Oct. 2006)
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Guo Y, Gu X, Zhang F, Mebel AM, Kaiser RI. A crossed molecular beam study on the formation of hexenediynyl radicals (H2CCCCCCH; C6H3(X2A′)) via reactions of tricarbon molecules, C3(X1Σg+), with allene (H2CCCH2; X1A1) and methylacetylene (CH3CCH; X1A1). Phys Chem Chem Phys 2007; 9:1972-9. [PMID: 17431525 DOI: 10.1039/b618179a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crossed molecular beams experiments have been utilized to investigate the reaction dynamics between two closed shell species, i.e. the reactions of tricarbon molecules, C(3)(X(1)Sigma(g)(+)), with allene (H(2)CCCH(2); X(1)A(1)), and with methylacetylene (CH(3)CCH; X(1)A(1)). Our investigations indicated that both these reactions featured characteristic threshold energies of 40-50 kJ mol(-1). The reaction dynamics are indirect and suggested the reactions proceeded via an initial addition of the tricarbon molecule to the unsaturated hydrocarbon molecules forming initially cyclic reaction intermediates of the generic formula C(6)H(4). The cyclic intermediates isomerize to yield eventually the acyclic isomers CH(3)CCCCCH (methylacetylene reaction) and H(2)CCCCCCH(2) (allene reaction). Both structures decompose via atomic hydrogen elimination to form the 1-hexene-3,4-diynyl-2 radical (C(6)H(3); H(2)CCCCCCH). Future flame studies utilizing the Advanced Light Source should therefore investigate the existence of 1-hexene-3,4-diynyl-2 radicals in high temperature methylacetylene and allene flames. Since the corresponding C(3)H(3), C(4)H(3), and C(5)H(3) radicals have been identified via their ionization potentials in combustion flames, the existence of the C(6)H(3) isomer 1-hexene-3,4-diynyl-2 can be predicted as well.
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Affiliation(s)
- Ying Guo
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA
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Goulay F, Osborn DL, Taatjes CA, Zou P, Meloni G, Leone SR. Direct detection of polyynes formation from the reaction of ethynyl radical (C2H) with propyne (CH3–CCH) and allene (CH2CCH2). Phys Chem Chem Phys 2007; 9:4291-300. [PMID: 17687477 DOI: 10.1039/b614502g] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The reactions of the ethynyl radical (C(2)H) with propyne and allene are studied at room temperature using an apparatus that combines the tunability of the vacuum ultraviolet radiation of the Advanced Light Source at Lawrence Berkeley National Laboratory with time-resolved mass spectrometry. The C(2)H radical is prepared by 193-nm photolysis of CF(3)CCH and the mass spectrum of the reacting mixture is monitored in time using synchrotron-photoionization with a dual-sector mass spectrometer. Analysis using photoionization efficiency curves allows the isomer-specific detection of individual polyynes of chemical formula C(5)H(4) produced by both reactions. The product branching ratios are estimated for each isomer. The reaction of propyne with ethynyl gives 50-70% diacetylene (H-C[triple bond]C-C[triple bond]C-H) and 50-30% C(5)H(4), with a C(5)H(4)-isomer distribution of 15-20% ethynylallene (CH(2)=C=CH-C[triple bond]CH) and 85-80% methyldiacetylene (CH(3)-C[triple bond]C-C[triple bond]CH). The reaction of allene with ethynyl gives 35-45% ethynylallene, 20-25% methyldiacetylene and 45-30% 1,4-pentadiyne (HC[triple bond]C-CH(2)-C[triple bond]CH). Diacetylene is most likely not produced by this reaction; an upper limit of 30% on the branching fraction to diacetylene can be derived from the present experiment. The mechanisms of polyynes formation by these reactions as well as the implications for Titan's atmospheric chemistry are discussed.
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Affiliation(s)
- Fabien Goulay
- Departments of Chemistry and Physics, and Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA
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Yang B, Huang C, Wei L, Wang J, Sheng L, Zhang Y, Qi F, Zheng W, Li WK. Identification of isomeric C5H3 and C5H5 free radicals in flame with tunable synchrotron photoionization. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.03.081] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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