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Ross SD, Flores J, Khani S, Hewett DM, Reilly NJ. Optical Identification of the Resonance-Stabilized para-Ethynylbenzyl Radical. J Phys Chem A 2021; 125:9115-9127. [PMID: 34614356 DOI: 10.1021/acs.jpca.1c07039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the spectroscopic observation of the jet-cooled para-ethynylbenzyl (PEB) radical, a resonance-stabilized isomer of C9H7. The radical was produced in a discharge of p-ethynyltoluene diluted in argon and probed by resonant two-color two-photon ionization (R2C2PI) spectroscopy. The origin of the D0(2B1)-D1(2B1) transition of PEB appears at 19,506 cm-1. A resonant two-color ion-yield scan reveals an adiabatic ionization energy (AIE) of 7.177(1) eV, which is almost symmetrically bracketed by CBS-QB3 and B3LYP/6-311G++(d,p) calculations. The electronic spectrum exhibits pervasive Fermi resonances, in that most a1 fundamentals are accompanied by similarly intense overtones or combination bands of non-totally symmetric modes that would carry little intensity in the harmonic approximation. Under the same experimental conditions, the m/z = 115 R2C2PI spectrum of the p-ethynyltoluene discharge also exhibits contributions from the m-ethynylbenzyl and 1-phenylpropargyl radicals. The former, like PEB, is observed herein for the first time, and its identity is confirmed by measurement and calculation of its AIE and D0-D1 origin transition energy; the latter is identified by comparison with its known electronic spectrum (J. Am. Chem. Soc., 2008, 130, 3137-3142). Both species are found to co-exist with PEB at levels vastly greater than might be explained by any precursor sample impurity, implying that interconversion of ethynylbenzyl motifs is feasible in energetic environments such as plasmas and flames, wherein resonance-stabilized radicals are persistent.
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Affiliation(s)
- Sederra D Ross
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United States
| | - Jonathan Flores
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United States
| | - Sima Khani
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United States
| | - Daniel M Hewett
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United States
| | - Neil J Reilly
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United States
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Constantinidis P, Hirsch F, Fischer I, Dey A, Rijs AM. Products of the Propargyl Self-Reaction at High Temperatures Investigated by IR/UV Ion Dip Spectroscopy. J Phys Chem A 2016; 121:181-191. [DOI: 10.1021/acs.jpca.6b08750] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. Constantinidis
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am
Hubland, D-97074 Würzburg, Germany
| | - F. Hirsch
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am
Hubland, D-97074 Würzburg, Germany
| | - I. Fischer
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am
Hubland, D-97074 Würzburg, Germany
| | - A. Dey
- Radboud University, Institute for Molecules and
Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - A. M. Rijs
- Radboud University, Institute for Molecules and
Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
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Holzmeier F, Lang M, Fischer I, Tang X, Cunha de Miranda B, Romanzin C, Alcaraz C, Hemberger P. Threshold photoelectron spectroscopy of unstable N-containing compounds: Resolution of ΔK subbands in HNCO+ and vibrational resolution in NCO+. J Chem Phys 2015; 142:184306. [DOI: 10.1063/1.4920951] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Fabian Holzmeier
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Melanie Lang
- 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
| | - Xiaofeng Tang
- Synchrotron SOLEIL, l’Orme des Merisiers, Saint Aubin BP 48, F-91192 Gif sur Yvette Cedex, France
| | - Barbara Cunha de Miranda
- Laboratoire de Chimie-Physique, UMR 8000 CNRS and Université Paris-Sud 11, F-91405 Orsay Cedex, France
| | - Claire Romanzin
- Laboratoire de Chimie-Physique, UMR 8000 CNRS and Université Paris-Sud 11, F-91405 Orsay Cedex, France
| | - Christian Alcaraz
- Laboratoire de Chimie-Physique, UMR 8000 CNRS and Université Paris-Sud 11, F-91405 Orsay Cedex, France
| | - Patrick Hemberger
- Molecular Dynamics Group, Paul Scherrer Institute (PSI), CH-5232 Villigen, Switzerland
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Lang M, Holzmeier F, Hemberger P, Fischer I. Threshold Photoelectron Spectra of Combustion Relevant C4H5 and C4H7 Isomers. J Phys Chem A 2015; 119:3995-4000. [DOI: 10.1021/acs.jpca.5b02153] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Melanie Lang
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg
| | - Fabian Holzmeier
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg
| | - Patrick Hemberger
- Molecular
Dynamics Group, Paul Scherrer Institut, CH-5232 Villigen
PSI, Switzerland
| | - Ingo Fischer
- Institute
of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg
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Holzmeier F, Lang M, Fischer I, Hemberger P, Garcia GA, Tang X, Loison JC. Assignment of high-lying bending mode levels in the threshold photoelectron spectrum of NH2: a comparison between pyrolysis and fluorine-atom abstraction radical sources. Phys Chem Chem Phys 2015; 17:19507-14. [DOI: 10.1039/c5cp02964c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bending mode progression in the photoelectron spectrum of NH2 was observed and assigned up to υ2+ ≤ 5 and Ka+ ≤ 3.
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Affiliation(s)
- F. Holzmeier
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - M. Lang
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - I. Fischer
- Institute of Physical and Theoretical Chemistry
- University of Würzburg
- D-97074 Würzburg
- Germany
| | - P. Hemberger
- Molecular Dynamics Group
- Paul Scherrer Institut CH-5232 Villigen
- Switzerland
| | | | - X. Tang
- Synchrotron SOLEIL
- 91192 Gif sur Yvette
- France
| | - J.-C. Loison
- ISM
- Université Bordeaux 1
- CNRS
- 33405 Talence Cedex
- France
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Krechkivska O, Wilcox C, O’Connor GD, Nauta K, Kable SH, Schmidt TW. Ionization Energies of Three Resonance-Stabilized Radicals: Cyclohexadienyl (dn, n = 0, 1, 6, 7), 1-Phenylpropargyl, and Methylcyclohexadienyl. J Phys Chem A 2014; 118:10252-8. [DOI: 10.1021/jp508985s] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Olha Krechkivska
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Callan Wilcox
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Gerard D. O’Connor
- School
of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - 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
| | - Timothy W. Schmidt
- School
of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
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