1
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Changala PB, Franke PR, Stanton JF, Ellison GB, McCarthy MC. Direct Probes of π-Delocalization in Prototypical Resonance-Stabilized Radicals: Hyperfine-Resolved Microwave Spectroscopy of Isotopic Propargyl and Cyanomethyl. J Am Chem Soc 2024; 146:1512-1521. [PMID: 38170910 DOI: 10.1021/jacs.3c11220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Delocalization of the unpaired electron in π-conjugated radicals has profound implications for their chemistry, but direct and quantitative characterization of this electronic structure in isolated molecules remains challenging. We apply hyperfine-resolved microwave rotational spectroscopy to rigorously probe π-delocalization in propargyl, CH2CCH, a prototypical resonance-stabilized radical and key reactive intermediate. Using the spectroscopic constants derived from the high-resolution cavity Fourier transform microwave measurements of an exhaustive set of 13C- and 2H-substituted isotopologues, together with high-level ab initio calculations of zero-point vibrational effects, we derive its precise semiexperimental equilibrium geometry and quantitatively characterize the spatial distribution of its unpaired electron. Our results highlight the importance of considering both spin-polarization and orbital-following contributions when interpreting the isotropic hyperfine coupling constants of π radicals. These physical insights are strengthened by a parallel analysis of the isoelectronic species cyanomethyl, CH2CN, using new 13C measurements also reported in this work. A detailed comparison of the structure and electronic properties of propargyl, cyanomethyl, and other closely related species allows us to correlate trends in their chemical bonding and electronic structure with critical changes in their reactivity and thermochemistry.
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Affiliation(s)
- P Bryan Changala
- Center for Astrophysics|Harvard & Smithsonian, Cambridge, Massachusetts 02138, United States
| | - Peter R Franke
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - John F Stanton
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - G Barney Ellison
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Michael C McCarthy
- Center for Astrophysics|Harvard & Smithsonian, Cambridge, Massachusetts 02138, United States
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2
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Carpenter BK, Ellison GB, Nimlos MR, Scheer AM. A Conical Intersection Influences the Ground State Rearrangement of Fulvene to Benzene. J Phys Chem A 2022; 126:1429-1447. [PMID: 35191307 DOI: 10.1021/acs.jpca.2c00038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rearrangement of fulvene to benzene is believed to play an important role in the formation of soot during hydrocarbon combustion. Previous work has identified two possible mechanisms for the rearrangement─a unimolecular path and a hydrogen-atom-assisted, bimolecular path. Computational results to date have suggested that the unimolecular mechanism faces a barrier of about 74 kcal/mol, which makes it unable to compete with the bimolecular mechanism under typical combustion conditions. This computed barrier is about 10 kcal/mol higher than the experimental value, which is an unusually large discrepancy for modern electronic structure theory. In the present work, we have reinvestigated the unimolecular mechanism computationally, and we have found a second transition state that is approximately 10 kcal/mol lower in energy than the previously identified one and, therefore, in excellent agreement with the experimental value. The existence of two transition states for the same rearrangement arises because there is a conical intersection between the two lowest singlet states which occurs in the vicinity of the reaction coordinates. The two possible paths around the cone on the lower adiabatic surface give rise to the two distinct saddle points. The lower barrier for the unimolecular mechanism now makes it competitive with the bimolecular one, according to our calculations. In support of this conclusion, we have reanalyzed some previous experimental results on anisole pyrolysis, which leads to benzene as a significant product and have shown that the unimolecular and bimolecular mechanisms for fulvene → benzene must be occurring competitively in that system. Finally, we have identified that similar conical intersections arise during the isomerizations of benzofulvene and isobenzofulvene to naphthalene.
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Affiliation(s)
- Barry K Carpenter
- School of Chemistry, Cardiff University, Main Building, Park PL, Cardiff CF10 3AT, U.K
| | - G Barney Ellison
- Department of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Mark R Nimlos
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Adam M Scheer
- Recurve Inc., 4014 South Lemay Avenue, Unit 22, Fort Collins, Colorado 80525, United States
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3
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Nguyen TL, Bross DH, Ruscic B, Ellison GB, Stanton J. Mechanism, Thermochemistry, and Kinetics of the Reversible Reactions: C2H3 + H2 ⇌ C2H4 + H ⇌ C2H5. Faraday Discuss 2022; 238:405-430. [DOI: 10.1039/d1fd00124h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-level coupled cluster theory, in conjunction with Active Thermochemical Tables (ATcT) and E,J-resolved master equation calculations were used in a study of the title reactions, which play an important role...
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4
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Bouwman J, Hrodmarsson HR, Ellison GB, Bodi A, Hemberger P. Five Birds with One Stone: Photoelectron Photoion Coincidence Unveils Rich Phthalide Pyrolysis Chemistry. J Phys Chem A 2021; 125:1738-1746. [PMID: 33616395 DOI: 10.1021/acs.jpca.1c00149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Phthalide pyrolysis has been assumed to be a clean fulvenallene source. We show that this is only true at low temperatures, and the C7H6 isomers 1-, 2-, and 5-ethynylcyclopentadiene are also formed at high pyrolysis temperatures. Photoion mass-selected threshold photoelectron spectra are analyzed with the help of (time-dependent) density functional theory, (TD-)DFT, and equation-of-motion ionization potential coupled cluster, EOM-IP-CCSD, calculations, as well as Franck-Condon simulations of partly overlapping bands, to determine ionization energies. The fulvenallene ionization energy is confirmed at 8.23 ± 0.01 eV, and the ionization energies of 1-, 2 and 5-ethynylcyclopentadiene are newly determined at 8.27 ± 0.01, 8.49 ± 0.01 and 8.76 ± 0.02 eV, respectively. Excited state features in the photoelectron spectrum, in particular the Ã+ 2A' band of 1-ethynylcyclopentadiene, are shown to be practical to isomer-selectively detect species when the ground-state band is congested. At high pyrolysis temperatures, the C7H6 isomers may lose a hydrogen atom and yield the fulvenallenyl radical. Its ionization energy is confirmed at 8.20 ± 0.01 eV. The vibrational fingerprint of the first triplet fulvenallenyl cation state is also revealed and yields an ionization energy of 8.33 ± 0.02 eV. Further triplet cation states are identified and modeled in the 10-11 eV range. A reaction mechanism is proposed based on potential energy surface calculations. Based on a simplified reactor model, we show that the C7H6 isomer distribution is far from thermal equilibrium in the reactor, presumably because irreversible H loss competes efficiently with isomerization.
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Affiliation(s)
- Jordy Bouwman
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
| | - Helgi R Hrodmarsson
- Laboratory for Astrophysics, Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
| | - G Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, Colorado 80309-0215, United States
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
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5
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Hemberger P, Pan Z, Bodi A, Bokhoven JA, Ormond TK, Ellison GB, Genossar N, Baraban JH. The Threshold Photoelectron Spectrum of Fulvenone: A Reactive Ketene Derivative in Lignin Valorization. Chemphyschem 2020; 21:2217-2222. [DOI: 10.1002/cphc.202000477] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/29/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Patrick Hemberger
- Laboratory for Synchrotron Radiation and Femtochemistry Paul Scherrer Institute CH-5232 Villigen PSI Switzerland
| | - Zeyou Pan
- Laboratory for Synchrotron Radiation and Femtochemistry Paul Scherrer Institute CH-5232 Villigen PSI Switzerland
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Zurich Switzerland
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry Paul Scherrer Institute CH-5232 Villigen PSI Switzerland
| | - Jeroen A. Bokhoven
- Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Zurich Switzerland
- Laboratory for Catalysis and Sustainable Chemistry Paul Scherrer Institute CH-5232 Villigen PSI Switzerland
| | - Thomas K. Ormond
- Department of Chemistry and Biochemistry University of Colorado Boulder Colorado 80309-0215 United States
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry University of Colorado Boulder Colorado 80309-0215 United States
| | - Nadav Genossar
- Department of Chemistry Ben Gurion University of the Negev Beer Sheva 84105 Israel
- Israel Atomic Energy Commission Tel Aviv 61070 Israel
| | - Joshua H. Baraban
- Department of Chemistry Ben Gurion University of the Negev Beer Sheva 84105 Israel
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6
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Ormond TK, Baraban JH, Porterfield JP, Scheer AM, Hemberger P, Troy TP, Ahmed M, Nimlos MR, Robichaud DJ, Daily JW, Ellison GB. Thermal Decompositions of the Lignin Model Compounds: Salicylaldehyde and Catechol. J Phys Chem A 2018; 122:5911-5924. [DOI: 10.1021/acs.jpca.8b03201] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Thomas K. Ormond
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Joshua H. Baraban
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Jessica P. Porterfield
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Adam M. Scheer
- Combustion Research Facility, Sandia National Laboratory, PO Box 969, Livermore, California 94551-0969, United States
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation, Paul Scherrer Institute, CH-5234 Villigen-PSI, Switzerland
| | - Tyler P. Troy
- Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Mark R. Nimlos
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - David J. Robichaud
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - John W. Daily
- Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309-0427, United States
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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7
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Baraban JH, Martin‐Drumel M, Changala PB, Eibenberger S, Nava M, Patterson D, Stanton JF, Ellison GB, McCarthy MC. The Molecular Structure of
gauche
‐1,3‐Butadiene: Experimental Establishment of Non‐planarity. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201709966] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Joshua H. Baraban
- Department of Chemistry and Biochemistry University of Colorado Boulder CO 80309 USA
- Current address: Dept. of Chemistry Ben-Gurion University of the Negev Beer-Sheva 84105 Israel
| | - Marie‐Aline Martin‐Drumel
- Harvard-Smithsonian Center for Astrophysics and School of Engineering & Applied Sciences Harvard University Cambridge Massachusetts 02138 USA
- Current address: Institut des Sciences Moléculaires d'Orsay, CNRS Univ. Paris-Sud, Université Paris-Saclay Orsay France
| | - P. Bryan Changala
- JILA, National Institute of Standards and Technology and Department of Physics University of Colorado Boulder CO 80309 USA
| | | | - Matthew Nava
- Department of Chemistry Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
- Current address: Department of Chemistry Harvard University Cambridge MA 02138 USA
| | - David Patterson
- Department of Physics Harvard University Cambridge MA 02138 USA
- Current address: Department of Physics University of California Santa Barbara CA 93106 USA
| | - John F. Stanton
- Quantum Theory Project Depts. of Chemistry and Physics Univ. of Florida Gainesville FL 32611 USA
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry University of Colorado Boulder CO 80309 USA
| | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics and School of Engineering & Applied Sciences Harvard University Cambridge Massachusetts 02138 USA
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8
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Baraban JH, Martin‐Drumel M, Changala PB, Eibenberger S, Nava M, Patterson D, Stanton JF, Ellison GB, McCarthy MC. The Molecular Structure of
gauche
‐1,3‐Butadiene: Experimental Establishment of Non‐planarity. Angew Chem Int Ed Engl 2018; 57:1821-1825. [DOI: 10.1002/anie.201709966] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Joshua H. Baraban
- Department of Chemistry and Biochemistry University of Colorado Boulder CO 80309 USA
- Current address: Dept. of Chemistry Ben-Gurion University of the Negev Beer-Sheva 84105 Israel
| | - Marie‐Aline Martin‐Drumel
- Harvard-Smithsonian Center for Astrophysics and School of Engineering & Applied Sciences Harvard University Cambridge Massachusetts 02138 USA
- Current address: Institut des Sciences Moléculaires d'Orsay, CNRS Univ. Paris-Sud, Université Paris-Saclay Orsay France
| | - P. Bryan Changala
- JILA, National Institute of Standards and Technology and Department of Physics University of Colorado Boulder CO 80309 USA
| | | | - Matthew Nava
- Department of Chemistry Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
- Current address: Department of Chemistry Harvard University Cambridge MA 02138 USA
| | - David Patterson
- Department of Physics Harvard University Cambridge MA 02138 USA
- Current address: Department of Physics University of California Santa Barbara CA 93106 USA
| | - John F. Stanton
- Quantum Theory Project Depts. of Chemistry and Physics Univ. of Florida Gainesville FL 32611 USA
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry University of Colorado Boulder CO 80309 USA
| | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics and School of Engineering & Applied Sciences Harvard University Cambridge Massachusetts 02138 USA
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9
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Changala PB, Nguyen TL, Baraban JH, Ellison GB, Stanton JF, Bross DH, Ruscic B. Active Thermochemical Tables: The Adiabatic Ionization Energy of Hydrogen Peroxide. J Phys Chem A 2017; 121:8799-8806. [DOI: 10.1021/acs.jpca.7b06221] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Bryan Changala
- JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, CO 80309, United States
| | - T. Lam Nguyen
- Quantum
Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, FL 32611, United States
| | - Joshua H. Baraban
- Department
of Chemistry, University of Colorado, Boulder, CO 80302, United States
| | - G. Barney Ellison
- Department
of Chemistry, University of Colorado, Boulder, CO 80302, United States
| | - John F. Stanton
- Quantum
Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, FL 32611, United States
| | - David H. Bross
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, United States
| | - Branko Ruscic
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, United States
- Computation
Institute, The University of Chicago, Chicago, IL 60637, United States
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10
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Couch DE, Buckingham GT, Baraban JH, Porterfield JP, Wooldridge LA, Ellison GB, Kapteyn HC, Murnane MM, Peters WK. Tabletop Femtosecond VUV Photoionization and PEPICO Detection of Microreactor Pyrolysis Products. J Phys Chem A 2017; 121:5280-5289. [DOI: 10.1021/acs.jpca.7b02821] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David E. Couch
- JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - Grant T. Buckingham
- Department
of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Joshua H. Baraban
- Department
of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | | | - Laura A. Wooldridge
- JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - G. Barney Ellison
- Department
of Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Henry C. Kapteyn
- JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - Margaret M. Murnane
- JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
| | - William K. Peters
- JILA and Department of Physics, University of Colorado, Boulder, Colorado 80309, United States
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11
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Porterfield JP, Bross DH, Ruscic B, Thorpe JH, Nguyen TL, Baraban JH, Stanton JF, Daily JW, Ellison GB. Thermal Decomposition of Potential Ester Biofuels. Part I: Methyl Acetate and Methyl Butanoate. J Phys Chem A 2017; 121:4658-4677. [PMID: 28517940 DOI: 10.1021/acs.jpca.7b02639] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two methyl esters were examined as models for the pyrolysis of biofuels. Dilute samples (0.06-0.13%) of methyl acetate (CH3COOCH3) and methyl butanoate (CH3CH2CH2COOCH3) were entrained in (He, Ar) carrier gas and decomposed in a set of flash-pyrolysis microreactors. The pyrolysis products resulting from the methyl esters were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by matrix infrared absorption spectroscopy. Pyrolysis pressures in the pulsed microreactor were about 20 Torr and residence times through the reactors were roughly 25-150 μs. Reactor temperatures of 300-1600 K were explored. Decomposition of CH3COOCH3 commences at 1000 K, and the initial products are (CH2═C═O and CH3OH). As the microreactor is heated to 1300 K, a mixture of CH2═C═O and CH3OH, CH3, CH2═O, H, CO, and CO2 appears. The thermal cracking of CH3CH2CH2COOCH3 begins at 800 K with the formation of CH3CH2CH═C═O and CH3OH. By 1300 K, the pyrolysis of methyl butanoate yields a complex mixture of CH3CH2CH═C═O, CH3OH, CH3, CH2═O, CO, CO2, CH3CH═CH2, CH2CHCH2, CH2═C═CH2, HCCCH2, CH2═C═C═O, CH2═CH2, HC≡CH, and CH2═C═O. On the basis of the results from the thermal cracking of methyl acetate and methyl butanoate, we predict several important decomposition channels for the pyrolysis of fatty acid methyl esters, R-CH2-COOCH3. The lowest-energy fragmentation will be a 4-center elimination of methanol to form the ketene RCH═C═O. At higher temperatures, concerted fragmentation to radicals will ensue to produce a mixture of species: (RCH2 + CO2 + CH3) and (RCH2 + CO + CH2═O + H). Thermal cracking of the β C-C bond of the methyl ester will generate the radicals (R and H) as well as CH2═C═O + CH2═O. The thermochemistry of methyl acetate and its fragmentation products were obtained via the Active Thermochemical Tables (ATcT) approach, resulting in ΔfH298(CH3COOCH3) = -98.7 ± 0.2 kcal mol-1, ΔfH298(CH3CO2) = -45.7 ± 0.3 kcal mol-1, and ΔfH298(COOCH3) = -38.3 ± 0.4 kcal mol-1.
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Affiliation(s)
| | - David H Bross
- Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Branko Ruscic
- Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.,Computation Institute, The University of Chicago , Chicago, Illinois 60637, United States
| | - James H Thorpe
- Department of Chemistry, University of Texas , Austin, Texas 78712, United States
| | - Thanh Lam Nguyen
- Department of Chemistry, University of Texas , Austin, Texas 78712, United States
| | | | - John F Stanton
- Department of Chemistry, University of Texas , Austin, Texas 78712, United States.,Department of Chemistry, University of Florida , Gainesville, Florida 32611, United States
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Buckingham GT, Porterfield JP, Kostko O, Troy TP, Ahmed M, Robichaud DJ, Nimlos MR, Daily JW, Ellison GB. The thermal decomposition of the benzyl radical in a heated micro-reactor. II. Pyrolysis of the tropyl radical. J Chem Phys 2016; 145:014305. [DOI: 10.1063/1.4954895] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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 Bioenergy Center, 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
| | - Oleg Kostko
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Tyler P. Troy
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - David J. Robichaud
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden Colorado 80401, USA
| | - Mark R. Nimlos
- National Bioenergy Center, 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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13
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Porterfield JP, Baraban JH, Troy TP, Ahmed M, McCarthy MC, Morgan KM, Daily JW, Nguyen TL, Stanton JF, Ellison GB. Pyrolysis of the Simplest Carbohydrate, Glycolaldehyde (CHO−CH2OH), and Glyoxal in a Heated Microreactor. J Phys Chem A 2016; 120:2161-72. [DOI: 10.1021/acs.jpca.6b00652] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Tyler P. Troy
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Michael C. McCarthy
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, United States
| | - Kathleen M. Morgan
- Department
of Chemistry, Xavier University of Louisiana, New Orleans, Louisiana 70125-1098, United States
| | | | - Thanh Lam Nguyen
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - John F. Stanton
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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14
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Abstract
We report an optically accessible pyrolysis micro-reactor suitable for in situ laser spectroscopic measurements. A radiative heating design allows for completely unobstructed views of the micro-reactor along two axes. The maximum temperature demonstrated here is only 1300 K (as opposed to 1700 K for the usual SiC micro-reactor) because of the melting point of fused silica, but alternative transparent materials will allow for higher temperatures. Laser induced fluorescence measurements on nitric oxide are presented as a proof of principle for spectroscopic characterization of pyrolysis conditions.
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Affiliation(s)
- J H Baraban
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - D E David
- Integrated Instrument Development Facility, CIRES, University of Colorado, Boulder, Colorado 80309-0216, USA
| | - G Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | - J W Daily
- Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309, USA
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15
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Porterfield JP, Nguyen TL, Baraban JH, Buckingham GT, Troy TP, Kostko O, Ahmed M, Stanton JF, Daily JW, Ellison GB. Isomerization and Fragmentation of Cyclohexanone in a Heated Micro-Reactor. J Phys Chem A 2015; 119:12635-47. [DOI: 10.1021/acs.jpca.5b10984] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jessica P. Porterfield
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Thanh Lam Nguyen
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Joshua H. Baraban
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Grant T. Buckingham
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Tyler P. Troy
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Oleg Kostko
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - John F. Stanton
- Department
of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - John W. Daily
- Center
for Combustion and Environmental Research, Department of Mechanical
Engineering, University of Colorado, Boulder, Colorado 80309-0427, United States
| | - G. Barney Ellison
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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16
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Abstract
Substituted furans, including furanic ethers, derived from nonedible biomass have been proposed as second-generation biofuels. In order to use these molecules as fuels, it is important to understand how they break apart thermally. In this work, a series of experiments were conducted to study the unimolecular and low-pressure bimolecular decomposition mechanisms of the smallest furanic ether, 2-methoxyfuran. Electronic structure (CBS-QB3) calculations indicate this substituted furan has an unusually weak O-CH3 bond, approximately 190 kJ mol(-1) (45 kcal mol(-1)); thus, the primary decomposition pathway is through bond scission resulting in CH3 and 2-furanyloxy (O-C4H3O) radicals. Final products from the ring opening of the furanyloxy radical include 2 CO, HC≡CH, and H. The decomposition of methoxyfuran is studied over a range of concentrations (0.0025-0.1%) in helium or argon in a heated silicon carbide (SiC) microtubular flow reactor (0.66-1 mm i.d., 2.5-3.5 cm long) with reactor wall temperatures from 300 to 1300 K. Inlet pressures to the reactor are 150-1500 Torr, and the gas mixture emerges as a skimmed molecular beam at a pressure of approximately 10 μTorr. Products formed at early pyrolysis times (100 μs) are detected by 118.2 nm (10.487 eV) photoionization mass spectrometry (PIMS), tunable synchrotron VUV PIMS, and matrix infrared absorption spectroscopy. Secondary products resulting from H or CH3 addition to the parent and reaction with 2-furanyloxy were also observed and include CH2═CH-CHO, CH3-CH═CH-CHO, CH3-CO-CH═CH2, and furanones; under the conditions in the reactor, we estimate these reactions contribute to at most 1-3% of total methoxyfuran decomposition. This work also includes observation and characterization of an allylic lactone radical, 2-furanyloxy (O-C4H3O), with the assignment of several intense vibrational bands in an Ar matrix, an estimate of the ionization threshold, and photoionization efficiency. A pressure-dependent kinetic mechanism is also developed to model the decomposition behavior of methoxyfuran and provide pathways for the minor bimolecular reaction channels that are observed experimentally.
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Affiliation(s)
- Kimberly N Urness
- Department of Mechanical Engineering, University of Colorado , Boulder, Colorado 80309-0427, United States
| | - Qi Guan
- Department of Mechanical Engineering, University of Colorado , Boulder, Colorado 80309-0427, United States
| | - Tyler P Troy
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , MS 6R-2100, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , MS 6R-2100, Berkeley, California 94720, United States
| | - John W Daily
- Department of Mechanical Engineering, University of Colorado , Boulder, Colorado 80309-0427, United States
| | - G Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado , Boulder, Colorado 80309-0215, United States
| | - John M Simmie
- Combustion Chemistry Centre, School of Chemistry, National University of Ireland , Galway, Ireland
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17
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Ormond TK, Hemberger P, Troy TP, Ahmed M, Stanton JF, Ellison GB. The ionisation energy of cyclopentadienone: a photoelectron–photoion coincidence study. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1042936] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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18
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Prozument K, Barratt Park G, Shaver RG, Vasiliou AK, Oldham JM, David DE, Muenter JS, Stanton JF, Suits AG, Barney Ellison G, Field RW. Chirped-Pulse millimeter-Wave spectroscopy for dynamics and kinetics studies of pyrolysis reactions. Phys Chem Chem Phys 2015; 16:15739-15751. [PMID: 24756159 DOI: 10.1039/c3cp55352c] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Chirped-Pulse millimeter-Wave (CPmmW) spectrometer is applied to the study of chemical reaction products that result from pyrolysis in a Chen nozzle heated to 1000-1800 K. Millimeter-wave rotational spectroscopy unambiguously determines, for each polar reaction product, the species, the conformers, relative concentrations, conversion percentage from precursor to each product, and, in some cases, vibrational state population distributions. A chirped-pulse spectrometer can, within the frequency range of a single chirp, sample spectral regions of up to ∼10 GHz and simultaneously detect many reaction products. Here we introduce a modification to the CPmmW technique in which multiple chirps of different spectral content are applied to a molecular beam pulse that contains the pyrolysis reaction products. This technique allows for controlled allocation of its sensitivity to specific molecular transitions and effectively doubles the bandwidth of the spectrometer. As an example, the pyrolysis reaction of ethyl nitrite, CH3CH2ONO, is studied, and CH3CHO, H2CO, and HNO products are simultaneously observed and quantified, exploiting the multi-chirp CPmmW technique. Rotational and vibrational temperatures of some product molecules are determined. Subsequent to supersonic expansion from the heated nozzle, acetaldehyde molecules display a rotational temperature of 4 ± 1 K. Vibrational temperatures are found to be controlled by the collisional cooling in the expansion, and to be both species- and vibrational mode-dependent. Rotational transitions of vibrationally excited formaldehyde in levels ν4, 2ν4, 3ν4, ν2, ν3, and ν6 are observed and effective vibrational temperatures for modes 2, 3, 4, and 6 are determined and discussed.
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Affiliation(s)
- Kirill Prozument
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA. and Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA
| | - G Barratt Park
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - Rachel G Shaver
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
| | - AnGayle K Vasiliou
- Department of Chemistry and Biochemistry, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05753, USA
| | - James M Oldham
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA
| | - Donald E David
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Cristol Chemistry 58, Boulder, CO 80309, USA
| | - John S Muenter
- Department of Chemistry, University of Rochester, 120 Trustee Road, Rochester, NY 14627, USA
| | - John F Stanton
- Department of Chemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712-0165, USA
| | - Arthur G Suits
- Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA
| | - G Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado at Boulder, Cristol Chemistry 58, Boulder, CO 80309, USA
| | - Robert W Field
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA.
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19
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Ormond TK, Scheer AM, Nimlos MR, Robichaud DJ, Troy TP, Ahmed M, Daily JW, Nguyen TL, Stanton JF, Ellison GB. Pyrolysis of Cyclopentadienone: Mechanistic Insights from a Direct Measurement of Product Branching Ratios. J Phys Chem A 2015; 119:7222-34. [DOI: 10.1021/jp511390f] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Thomas K. Ormond
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Adam M. Scheer
- Combustion
Research Facility, Sandia National Laboratory, PO Box 969, Livermore, California 94551-0969, United States
| | - Mark R. Nimlos
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - David J. Robichaud
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Tyler P. Troy
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical
Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720, United States
| | - John W. Daily
- Center
for Combustion and Environmental Research, Department of Mechanical
Engineering, University of Colorado, Boulder, Colorado 80309-0427, United States
| | - Thanh Lam Nguyen
- Institute
for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - John F. Stanton
- Institute
for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - G. Barney Ellison
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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20
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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21
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Guan Q, Urness KN, Ormond TK, David DE, Barney Ellison G, Daily JW. The properties of a micro-reactor for the study of the unimolecular decomposition of large molecules. INT REV PHYS CHEM 2014. [DOI: 10.1080/0144235x.2014.967951] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Kidwell NM, Vaquero-Vara V, Ormond TK, Buckingham GT, Zhang D, Mehta-Hurt DN, McCaslin L, Nimlos MR, Daily JW, Dian BC, Stanton JF, Ellison GB, Zwier TS. Chirped-Pulse Fourier Transform Microwave Spectroscopy Coupled with a Flash Pyrolysis Microreactor: Structural Determination of the Reactive Intermediate Cyclopentadienone. J Phys Chem Lett 2014; 5:2201-2207. [PMID: 26279534 DOI: 10.1021/jz5010895] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Chirped-pulse Fourier transform microwave spectroscopy (CP-FTMW) is combined with a flash pyrolysis (hyperthermal) microreactor as a novel method to investigate the molecular structure of cyclopentadienone (C5H4═O), a key reactive intermediate in biomass decomposition and aromatic oxidation. Samples of C5H4═O were generated cleanly from the pyrolysis of o-phenylene sulfite and cooled in a supersonic expansion. The (13)C isotopic species were observed in natural abundance in both C5H4═O and in C5D4═O samples, allowing precise measurement of the heavy atom positions in C5H4═O. The eight isotopomers include: C5H4═O, C5D4═O, and the singly (13)C isotopomers with (13)C substitution at the C1, C2, and C3 positions. Microwave spectra were interpreted by CCSD(T) ab initio electronic structure calculations and an re molecular structure for C5H4═O was found. Comparisons of the structure of this "anti-aromatic" molecule are made with those of comparable organic molecules, and it is concluded that the disfavoring of the "anti-aromatic" zwitterionic resonance structure is consistent with a more pronounced C═C/C-C bond alternation.
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Affiliation(s)
- Nathanael M Kidwell
- †Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Vanesa Vaquero-Vara
- †Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Thomas K Ormond
- ‡National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- ∥Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Grant T Buckingham
- ‡National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- ∥Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Di Zhang
- †Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Deepali N Mehta-Hurt
- †Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - Laura McCaslin
- ¶Institute of Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Mark R Nimlos
- ‡National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - John W Daily
- ⊥Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309-0427, United States
| | - Brian C Dian
- †Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
| | - John F Stanton
- ¶Institute of Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - G Barney Ellison
- ∥Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Timothy S Zwier
- †Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, United States
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23
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Robichaud DJ, Scheer AM, Mukarakate C, Ormond TK, Buckingham GT, Ellison GB, Nimlos MR. Unimolecular thermal decomposition of dimethoxybenzenes. J Chem Phys 2014; 140:234302. [DOI: 10.1063/1.4879615] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Abstract
A silicon carbide microtubular reactor has been used to measure branching ratios in the thermal decomposition of furan, C4H4O. The pyrolysis experiments are carried out by passing a dilute mixture of furan (approximately 0.01%) entrained in a stream of helium through the heated reactor. The SiC reactor (0.66 mm i.d., 2 mm o.d., 2.5 cm long) operates with continuous flow. Experiments were performed with a reactor inlet pressure of 100-300 Torr and a wall temperature between 1200 and 1600 K; characteristic residence times in the reactor are 60-150 μs. The unimolecular decomposition pathway of furan is confirmed to be: furan (+ M) ⇌ α-carbene or β-carbene. The α-carbene fragments to CH2=C=O + HC≡CH while the β-carbene isomerizes to CH2=C=CHCHO. The formyl allene can isomerize to CO + CH3C≡CH or it can fragment to H + CO + HCCCH2. Tunable synchrotron radiation photoionization mass spectrometry is used to monitor the products and to measure the branching ratio of the two carbenes as well as the ratio of [HCCCH2]/[CH3C≡CH]. The results of these pyrolysis experiments demonstrate a preference for 80%-90% of furan decomposition to occur via the β-carbene. For reactor temperatures of 1200-1400 K, no propargyl radicals are formed. As the temperature rises to 1500-1600 K, at most 10% of the decomposition of CH2=C=CHCHO produces H + CO + HCCCH2 radicals. Thermodynamic conditions in the reactor have been modeled by computational fluid dynamics and the experimental results are compared to the predictions of three furan pyrolysis mechanisms. Uncertainty in the pressure-dependency of the initiation reaction rates is a possible a source of discrepancy between experimental results and theoretical predictions.
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Affiliation(s)
- Kimberly N Urness
- Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309-0427, USA
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25
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Ormond TK, Scheer AM, Nimlos MR, Robichaud DJ, Daily JW, Stanton JF, Ellison GB. Polarized Matrix Infrared Spectra of Cyclopentadienone: Observations, Calculations, and Assignment for an Important Intermediate in Combustion and Biomass Pyrolysis. J Phys Chem A 2014; 118:708-18. [DOI: 10.1021/jp411257k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Thomas K. Ormond
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - Adam M. Scheer
- Combustion
Research Facility, Sandia National Laboratory, P. O. Box 969, Livermore, California 94551-0969, United States
| | - Mark R. Nimlos
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - David J. Robichaud
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - John W. Daily
- Center
for Combustion and Environmental Research, Department of Mechanical
Engineering, University of Colorado, Boulder, Colorado 80309-0427, United States
| | - John F. Stanton
- Institute
for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - G. Barney Ellison
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
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26
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Nguyen TL, Xue BC, Ellison GB, Stanton JF. Theoretical Study of Reaction of Ketene with Water in the Gas Phase: Formation of Acetic Acid? J Phys Chem A 2013; 117:10997-1005. [DOI: 10.1021/jp408337y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thanh Lam Nguyen
- Department
of Chemistry & Biochemistry, The University of Texas at Austin, Austin, Texas 78712-0165, United States
| | - Bert C. Xue
- Department
of Chemistry & Biochemistry, The University of Texas at Austin, Austin, Texas 78712-0165, United States
| | - G. Barney Ellison
- Department
of Chemistry and Biochemistry, University of Colorado at Boulder, 215 UCB, Boulder, Colorado 80309, United States
| | - John F. Stanton
- Department
of Chemistry & Biochemistry, The University of Texas at Austin, Austin, Texas 78712-0165, United States
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27
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Vasiliou AK, Kim JH, Ormond TK, Piech KM, Urness KN, Scheer AM, Robichaud DJ, Mukarakate C, Nimlos MR, Daily JW, Guan Q, Carstensen HH, Ellison GB. Biomass pyrolysis: Thermal decomposition mechanisms of furfural and benzaldehyde. J Chem Phys 2013; 139:104310. [DOI: 10.1063/1.4819788] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Abstract
Bond dissociation enthalpies (BDEs) can exhibit dramatic variations resulting from substituent effects. The remarkable range of experimental OH bond dissociation enthalpies have been reproduced using CBS-APNO calculations with very good accuracy, so we have employed these calculations to extend the available BDE data. The effect on these BDEs of lone pairs on the atom adjacent to oxygen shows that conjugation in the product radicals is the most important interaction leading to the wide range of values. The BDE's were found to be linearly related to both the spin density at the radical center and to the change in X-O bond order in going from X-O-H to X-O·.
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Affiliation(s)
- Kenneth B Wiberg
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA.
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Vasiliou AK, Piech KM, Reed B, Zhang X, Nimlos MR, Ahmed M, Golan A, Kostko O, Osborn DL, David DE, Urness KN, Daily JW, Stanton JF, Ellison GB. Thermal decomposition of CH3CHO studied by matrix infrared spectroscopy and photoionization mass spectroscopy. J Chem Phys 2012; 137:164308. [DOI: 10.1063/1.4759050] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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30
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Scheer AM, Mukarakate C, Robichaud DJ, Nimlos MR, Carstensen HH, Barney Ellison G. Unimolecular thermal decomposition of phenol and d5-phenol: Direct observation of cyclopentadiene formation via cyclohexadienone. J Chem Phys 2012; 136:044309. [DOI: 10.1063/1.3675902] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Scheer AM, Mukarakate C, Robichaud DJ, Nimlos MR, Ellison GB. Thermal Decomposition Mechanisms of the Methoxyphenols: Formation of Phenol, Cyclopentadienone, Vinylacetylene, and Acetylene. J Phys Chem A 2011; 115:13381-9. [DOI: 10.1021/jp2068073] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adam M. Scheer
- National Renewable Energy Laboratory 1617 Cole Blvd Golden, Colorado 80401-3393, United States
- Department of Chemistry and Biochemistry University of Colorado-Boulder Boulder, Colorado 80309-0215, United States
| | - Calvin Mukarakate
- National Renewable Energy Laboratory 1617 Cole Blvd Golden, Colorado 80401-3393, United States
| | - David J. Robichaud
- National Renewable Energy Laboratory 1617 Cole Blvd Golden, Colorado 80401-3393, United States
| | - Mark R. Nimlos
- National Renewable Energy Laboratory 1617 Cole Blvd Golden, Colorado 80401-3393, United States
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry University of Colorado-Boulder Boulder, Colorado 80309-0215, United States
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Vasiliou A, Piech KM, Zhang X, Nimlos MR, Ahmed M, Golan A, Kostko O, Osborn DL, Daily JW, Stanton JF, Barney Ellison G. The products of the thermal decomposition of CH3CHO. J Chem Phys 2011; 135:014306. [DOI: 10.1063/1.3604005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Mukarakate C, Scheer AM, Robichaud DJ, Jarvis MW, David DE, Ellison GB, Nimlos MR, Davis MF. Laser ablation with resonance-enhanced multiphoton ionization time-of-flight mass spectrometry for determining aromatic lignin volatilization products from biomass. Rev Sci Instrum 2011; 82:033104. [PMID: 21456715 DOI: 10.1063/1.3563704] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have designed and developed a laser ablation∕pulsed sample introduction∕mass spectrometry platform that integrates pyrolysis (py) and∕or laser ablation (LA) with resonance-enhanced multiphoton ionization (REMPI) reflectron time-of-flight mass spectrometry (TOFMS). Using this apparatus, we measured lignin volatilization products of untreated biomass materials. Biomass vapors are produced by either a custom-built hot stage pyrolysis reactor or laser ablation using the third harmonic of an Nd:YAG laser (355 nm). The resulting vapors are entrained in a free jet expansion of He, then skimmed and introduced into an ionization region. One color resonance-enhanced multiphoton ionization (1+1 REMPI) is used, resulting in highly selective detection of lignin subunits from complex vapors of biomass materials. The spectra obtained by py-REMPI-TOFMS and LA-REMPI-TOFMS display high selectivity and decreased fragmentation compared to spectra recorded by an electron impact ionization molecular beam mass spectrometer (EI-MBMS). The laser ablation method demonstrates the ability to selectively isolate and volatilize specific tissues within the same plant material and then detect lignin-based products from the vapors with enhanced sensitivity. The identification of select products observed in the LA-REMPI-TOFMS experiment is confirmed by comparing their REMPI wavelength scans with that of known standards.
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Affiliation(s)
- Calvin Mukarakate
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
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34
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Zhang X, Sander SP, Chaimowitz A, Ellison GB, Stanton JF. Detection of Vibrational Bending Mode ν8 and Overtone Bands of the Propargyl Radical, HCCCH2 X̃ 2B1. J Phys Chem A 2010; 114:12021-7. [DOI: 10.1021/jp105605f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xu Zhang
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, United States
| | - Stanley P. Sander
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, United States
| | - Adam Chaimowitz
- Chemistry Department, Pomona College, 645 N. College Avenue, Claremont, California 91711, United States
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - John F. Stanton
- Institute for Theoretical Chemistry, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
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Scheer AM, Mukarakate C, Robichaud DJ, Ellison GB, Nimlos MR. Radical Chemistry in the Thermal Decomposition of Anisole and Deuterated Anisoles: An Investigation of Aromatic Growth. J Phys Chem A 2010; 114:9043-56. [DOI: 10.1021/jp102046p] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Adam M. Scheer
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393 and Department of Chemistry and Biochemistry, University of Colorado-Boulder, Boulder, Colorado 80309-0215
| | - Calvin Mukarakate
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393 and Department of Chemistry and Biochemistry, University of Colorado-Boulder, Boulder, Colorado 80309-0215
| | - David J. Robichaud
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393 and Department of Chemistry and Biochemistry, University of Colorado-Boulder, Boulder, Colorado 80309-0215
| | - G. Barney Ellison
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393 and Department of Chemistry and Biochemistry, University of Colorado-Boulder, Boulder, Colorado 80309-0215
| | - Mark R. Nimlos
- National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401-3393 and Department of Chemistry and Biochemistry, University of Colorado-Boulder, Boulder, Colorado 80309-0215
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Villano SM, Eyet N, Wren SW, Ellison GB, Bierbaum VM, Lineberger WC. Photoelectron spectroscopy and thermochemistry of the peroxyformate anion. J Phys Chem A 2010; 114:191-200. [PMID: 19827803 DOI: 10.1021/jp907569w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The 351.1 nm photoelectron spectrum of the peroxyformate anion has been measured. The photoelectron spectrum displays vibronic features in both the 2A'' ground and 2A' first excited states of the corresponding radical. Franck-Condon simulations of the spectrum show that the ion is formed exclusively in the trans-conformation. The electron affinity (EA) of the peroxyformyl radical was determined to be 2.493 +/- 0.006 eV, while the term energy splitting was found to be 0.783-0.020+0.060 eV. Extended progressions in the C-OO (973 +/- 20 cm-1) and O-O (1098 +/- 20 cm-1) stretching modes are observed in the ground state of the radical. The fundamental frequency of the in-plane OCO bend was found to be 574 +/- 35 cm-1. The gas-phase acidity of peroxyformic acid has been determined using an ion-molecule bracketing technique. On the basis of the size of the trans- to cis- isomerization barrier, the measured acidity was assigned to the higher energy trans-conformer of the acid. The gas-phase acidity of the lower energy cis-conformer of peroxyformic acid was found from the measured acidity for the trans-form and a calculated energy correction: DeltaaG298(cis-peroxyformic acid) = 346.8 +/- 3.3 kcal mol-1 and DeltaaH298(cis-peroxyformic acid) = 354.4 +/- 3.3 kcal mol-1. Using a negative ion EA/acidity thermochemical cycle, the O-H bond dissociation energy (D0) values of the trans- and cis-conformers of peroxyformic acid to form the trans-radical were determined to be 94.0 +/- 3.3 and 97.1 +/- 3.3 kcal mol-1, respectively. The heat of formation (DeltafH298) of the trans-peroxyformyl radical was found to be -22.8 +/- 3.5 kcal mol-1.
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Affiliation(s)
- Stephanie M Villano
- JILA, University of Colorado and the National Institute of Standards and Technology and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440, USA
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Villano SM, Eyet N, Wren SW, Ellison GB, Bierbaum VM, Lineberger WC. Photoelectron spectroscopy and thermochemistry of the peroxyacetate anion. Eur J Mass Spectrom (Chichester) 2010; 16:255-268. [PMID: 20530835 DOI: 10.1255/ejms.1055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The 351.1 nm photoelectron spectrum of the peroxyacetate anion, (CH(3)C(O)OO(-)) was measured. Analysis of the spectrum shows that the observed spectral features arise almost exclusively from transitions between the trans-conformer of the anion and the X(2)A'' and A (2)A' states of the corresponding radical. The electron affinity of trans-CH(3)C(O)OO is 2.381+/- 0.007 eV and the term energy splitting of the A (2)A' state is 0.691 +/- 0.009 eV, in excellent agreement with two prior values [Zalyubovsky et al. J. Phys. Chem. A 107, 7704 (2003); Hu et al. J. Phys. Chem. 124, 114305/1 (2006); Hu et al. J. Phys. Chem. 110, 2629 (2006)]. The gas-phase acidity of trans-peroxyacetic acid was bracketed between the acidity of acetic acid and tert-butylthiol at Delta(a)G(298)(trans-CH(3)C(O)OOH)=1439 +/- 14 kJ mol(-1) and Delta(a)H(298)(trans-CH(3)C(O)OOH)=1467+/-14 kJ mol(-1). The acidity of cis-CH(3)C(O)OOH was found by adding a calculated energy correction to the acidity of the trans-conformer; Delta(a)G(298)[cis-CH(3)C(O)OOH] = 1461 +/- 14 kJ mol(-1) and Delta(a)H(298)[cis- CH(3)C(O)OOH]=1490+/-14 kJ mol(-1). The O-H bond dissociation energies for both conformers were determined using a negative ion thermodynamic cycle to be D(0)[trans- CH(3)C(O)OOH]=381+/-14 kJ mol(-1) and D(0)[cis- CH(3)C(O)OOH]=403+/-14 kJ mol(-1). The atmospheric implications of these results and relations to the thermochemistry of peroxyacetyl nitrate are discussed briefly.
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Affiliation(s)
- Stephanie M Villano
- JILA, University of Colorado and the National Institute of Standards and Technology and Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0440, USA
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Jochnowitz EB, Zhang X, Nimlos MR, Flowers BA, Stanton JF, Ellison GB. Infrared Spectrum of the Propargyl Peroxyl Radical, HC≡C—CH2OO X̃ 2A′′. J Phys Chem A 2009; 114:1498-507. [DOI: 10.1021/jp907806g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Evan B. Jochnowitz
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mail Stop D462, Los Alamos, New
| | - Xu Zhang
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mail Stop D462, Los Alamos, New
| | - Mark R. Nimlos
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mail Stop D462, Los Alamos, New
| | - Bradley A. Flowers
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mail Stop D462, Los Alamos, New
| | - John F. Stanton
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mail Stop D462, Los Alamos, New
| | - G. Barney Ellison
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, Earth and Environmental Sciences Division, Los Alamos National Laboratory, Mail Stop D462, Los Alamos, New
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Affiliation(s)
- AnGayle Vasiliou
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, and Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309-0427
| | - Mark R. Nimlos
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, and Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309-0427
| | - John W. Daily
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, and Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309-0427
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401, and Center for Combustion and Environmental Research, Department of Mechanical Engineering, University of Colorado at Boulder, Boulder, Colorado 80309-0427
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Kato S, Ellison GB, Bierbaum VM, Blanksby SJ. Base-Induced Decomposition of Alkyl Hydroperoxides in the Gas Phase. Part 3. Kinetics and Dynamics in HO− + CH3OOH, C2H5OOH, and tert-C4H9OOH Reactions. J Phys Chem A 2008; 112:9516-25. [DOI: 10.1021/jp800702z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shuji Kato
- Department of Chemistry and Biochemistry, University of Colorado and JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309, and School of Chemistry, University of Wollongong, NSW 2522, Australia
| | - G. Barney Ellison
- Department of Chemistry and Biochemistry, University of Colorado and JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309, and School of Chemistry, University of Wollongong, NSW 2522, Australia
| | - Veronica M. Bierbaum
- Department of Chemistry and Biochemistry, University of Colorado and JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309, and School of Chemistry, University of Wollongong, NSW 2522, Australia
| | - Stephen J. Blanksby
- Department of Chemistry and Biochemistry, University of Colorado and JILA, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309, and School of Chemistry, University of Wollongong, NSW 2522, Australia
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D'Andrea TM, Zhang X, Jochnowitz EB, Lindeman TG, Simpson CJSM, David DE, Curtiss TJ, Morris JR, Ellison GB. Oxidation of Organic Films by Beams of Hydroxyl Radicals. J Phys Chem B 2007; 112:535-44. [DOI: 10.1021/jp7096108] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Timothy M. D'Andrea
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - Xu Zhang
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - Evan B. Jochnowitz
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - T. G. Lindeman
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - C. J. S. M. Simpson
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - Donald E. David
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - Thomas J. Curtiss
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - John R. Morris
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
| | - G. Barney Ellison
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 19, CH-4056 Basel, Switzerland, Department of Chemistry, Colorado College, Colorado Springs, Colorado 80903-3298, Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, United Kingdom,
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Blanksby SJ, Bierbaum VM, Ellison GB, Kato S. Superoxide Does React with Peroxides: Direct Observation of the Haber–Weiss Reaction in the Gas Phase. Angew Chem Int Ed Engl 2007; 46:4948-50. [PMID: 17514688 DOI: 10.1002/anie.200700219] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stephen J Blanksby
- Department of Chemistry, University of Wollongong, Wollongong, NSW, Australia.
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Davis ME, Talukdar RK, Notte G, Ellison GB, Burkholder JB. Rate coefficients for the OH + pinonaldehyde (C10H16O2) reaction between 297 and 374 K. Environ Sci Technol 2007; 41:3959-65. [PMID: 17612175 DOI: 10.1021/es070048d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The rate coefficientforthe reaction of OH with pinonaldehyde (C10H16O2, 3-acetyl-2,2-dimethyl-cyclobutyl-ethanal), a product of the atmospheric oxidation of alpha-pinene, was measured under pseudo-first-order conditions in OH at temperatures between 297 and 374 K at 55 and 96 Torr (He). Laser induced fluorescence (LIF) was used to monitor OH in the presence of pinonaldehyde following its production by 248 nm pulsed laser photolysis of H2O2. The reaction exhibits a negative temperature dependence with an Arrhenius expression of k1(T) = (4.5 +/- 1.3) x 10(-12) exp((600 +/- 100)/ 7) cm3 molecule(-1) s(-1); k1(297 K) = (3.46 +/- 0.4) x 10(-11) cm3 molecule(-1) s(-1). There was no observed dependence of the rate coefficient on pressure. Our results are compared with previous relative rate determinations of k1 near 297 K and the discrepancies are discussed. The state of knowledge for the atmospheric processing of pinonaldehyde is reviewed, and its role as a marker for alpha-pinene (monoterpene) chemistry in the atmosphere is discussed.
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Affiliation(s)
- Maxine E Davis
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305-3328, USA
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Xing X, Reed B, Lau KC, Ng CY, Zhang X, Ellison GB. Vacuum ultraviolet laser pulsed field ionization-photoelectron study of allyl radical CH2CHCH2. J Chem Phys 2007; 126:171101. [PMID: 17492849 DOI: 10.1063/1.2737443] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The pulsed field ionization-photoelectron (PFI-PE) spectrum of allyl radical CH2CHCH2 (C3H5) in the energy range of 65 200-66 600 cm-1 has been measured using vacuum ultraviolet laser. Based on the simulation of the rotational structures resolved in the vibrational PFI-PE bands of C3H5+(X 1A1;0(0+) and nu7+=1), the ionization energies (IEs) of C3H5(X 2A2;0(0)) to form C3H5+(X 1A1;0(0+) and nu7+=1) are determined to be 65 584.6+/-2.0 cm-1 (8.131 46+/-0.000 25 eV) and 66 020.9+/-2.0 cm-1 (8.185 56+/-0.000 25 eV), respectively, where nu7+(a1) is the symmetric C-C-C bending mode of C3H5+(X 1A1). These values are compared to IE(C3H5) values obtained in previous experimental and high-level ab initio quantum theoretical studies.
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Affiliation(s)
- Xi Xing
- Department of Chemistry, University of California, Davis, Davis, California 95616
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Abstract
Cis, cis-peroxynitrous acid is known to be an intermediate in atmospheric reactions between OH and NO2 as well as HOO and NO. The infrared absorption spectra of matrix-isolated cc-HOONO and cc-DOONO in argon have been observed in the range of 500-8000 cm-1. Besides the seven fundamental vibrational modes that have been assigned earlier for this molecule [Zhang et al., J. Chem. Phys. 124, 084305 (2006)], more than 50 of the overtone and combination bands have been observed for cc-HOONO and cc-DOONO. Ab initio CCSD(T)/atomic natural orbital anharmonic force field calculations were used to help guide the assignments. Based on this study of the vibrational overtone transitions of cis, cis-HOONO that go as high as 8000 cm-1 and the earlier paper on the vibrational fundamentals, we conclude that the CCSD(T)/ANO anharmonic frequencies seem to correct to +/-35 cm-1. The success of the theoretically predicted anharmonic frequencies {upsilon} in assigning overtone spectra of HOONO up to 8000 cm-1 suggests that the CCSD(T)/ANO method is producing a reliable potential energy surface for this reactive molecule.
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Affiliation(s)
- Xu Zhang
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
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Zhang X, Maccarone AT, Nimlos MR, Kato S, Bierbaum VM, Ellison GB, Ruscic B, Simmonett AC, Allen WD, Schaefer HF. Unimolecular thermal fragmentation ofortho-benzyne. J Chem Phys 2007; 126:044312. [PMID: 17286475 DOI: 10.1063/1.2409927] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ortho-benzyne diradical, o-C(6)H(4) has been produced with a supersonic nozzle and its subsequent thermal decomposition has been studied. As the temperature of the nozzle is increased, the benzyne molecule fragments: o-C(6)H(4)+Delta--> products. The thermal dissociation products were identified by three experimental methods: (i) time-of-flight photoionization mass spectrometry, (ii) matrix-isolation Fourier transform infrared absorption spectroscopy, and (iii) chemical ionization mass spectrometry. At the threshold dissociation temperature, o-benzyne cleanly decomposes into acetylene and diacetylene via an apparent retro-Diels-Alder process: o-C(6)H(4)+Delta-->HC triple bond CH+HC triple bond C-C triple bond CH. The experimental Delta(rxn)H(298)(o-C(6)H(4)-->HC triple bond CH+HC triple bond C-C triple bond CH) is found to be 57+/-3 kcal mol(-1). Further experiments with the substituted benzyne, 3,6-(CH(3))(2)-o-C(6)H(2), are consistent with a retro-Diels-Alder fragmentation. But at higher nozzle temperatures, the cracking pattern becomes more complicated. To interpret these experiments, the retro-Diels-Alder fragmentation of o-benzyne has been investigated by rigorous ab initio electronic structure computations. These calculations used basis sets as large as [C(7s6p5d4f3g2h1i)H(6s5p4d3f2g1h)] (cc-pV6Z) and electron correlation treatments as extensive as full coupled cluster through triple excitations (CCSDT), in cases with a perturbative term for connected quadruples [CCSDT(Q)]. Focal point extrapolations of the computational data yield a 0 K barrier for the concerted, C(2v)-symmetric decomposition of o-benzyne, E(b)(o-C(6)H(4)-->HC triple bond CH+HC triple bond C-C triple bond CH)=88.0+/-0.5 kcal mol(-1). A barrier of this magnitude is consistent with the experimental results. A careful assessment of the thermochemistry for the high temperature fragmentation of benzene is presented: C(6)H(6)-->H+[C(6)H(5)]-->H+[o-C(6)H(4)]-->HC triple bond CH+HC triple bond C-C triple bond CH. Benzyne may be an important intermediate in the thermal decomposition of many alkylbenzenes (arenes). High engine temperatures above 1500 K may crack these alkylbenzenes to a mixture of alkyl radicals and phenyl radicals. The phenyl radicals will then dissociate first to benzyne and then to acetylene and diacetylene.
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Affiliation(s)
- Xu Zhang
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
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Zhang X, Nimlos MR, Ellison GB, Varner ME, Stanton JF. Infrared absorption spectra of matrix-isolated cis, cis-HOONO and its ab initio CCSD(T) anharmonic vibrational bands. J Chem Phys 2006; 124:084305. [PMID: 16512714 DOI: 10.1063/1.2163343] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The infrared absorption spectra of matrix-isolated cis, cis-peroxynitrous acid (HOONO and DOONO) in argon have been observed. Six of the nine fundamental vibrational modes for cis, cis-HOONO have been assigned definitively, and one tentatively. Coupled-cluster, ab initio anharmonic force field calculations were used to help guide some of the assignments. The experimental matrix frequencies (cm(-1)) for cis, cis-HOONO are (a' modes) nu1 = 3303+/-1, nu2 = 1600.6+/-0.6, nu3 = 1392+/-1, nu4 = 922.8+/-0.5, nu5 = 789.7+/-0.4, nu6 = 617+/-1; and (a" mode) nu8 = 462+/-1. The fundamentals for the deuterated isotopomer, cis, cis-DOONO, are (a' modes) nu1 = 2447.2+/-0.6, nu2 = 1595.7+/-0.7, nu3 = 1089.1+/-0.4, nu4 = 888.1+/-0.4, nu5 = 786.6+/-0.5, nu6 = 613.9+/-0.9; and (a" mode) nu8 = 456.5+/-0.5.
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Affiliation(s)
- Xu Zhang
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA.
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Jochnowitz EB, Zhang X, Nimlos MR, Varner ME, Stanton JF, Ellison GB. Propargyl Radical: Ab Initio Anharmonic Modes and the Polarized Infrared Absorption Spectra of Matrix-Isolated HCCCH2. J Phys Chem A 2005; 109:3812-21. [PMID: 16833697 DOI: 10.1021/jp040719j] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The propargyl radical has twelve fundamental vibrational modes, gamma(vib)(HCCCH2) = 5a1 [symbol: see text] 3b1 [symbol: see text] 4b2, and nine have been detected in a cryogenic matrix. Ab initio coupled-cluster anharmonic force field calculations were used to help guide some of the assignments. The experimental HC=:C-:CH2 matrix frequencies (cm(-1)) and polarizations are a1 modes--3308.5 +/- 0.5, 3028.3 +/- 0.6, 1935.4 +/- 0.4, 1440.4 +/- 0.5, 1061.6 +/- 0.8; b1 modes--686.6 +/- 0.4, 483.6 +/- 0.5; b2 modes--1016.7 +/- 0.4, 620 +/- 2. We recommend a complete set of gas-phase vibrational frequencies for the propargyl radical, HC=:C-:CH2 2 X (2)B1. From an analysis of the vibrational spectra, the small electric dipole moment, mu(D)(HCCCH2) = 0.150 D, and the large resonance energy (HCCCH2), roughly 11 kcal mol(-1), we conclude that propargyl is a completely delocalized hydrocarbon radical and is best written as HC=:C-:CH2.
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Affiliation(s)
- Evan B Jochnowitz
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, USA
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Zhang X, Kato S, Bierbaum VM, Nimlos MR, Ellison GB. Use of a Flowing Afterglow SIFT Apparatus To Study the Reactions of Ions with Organic Radicals. J Phys Chem A 2004. [DOI: 10.1021/jp047792u] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xu Zhang
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215
| | - Shuji Kato
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215
| | - Veronica M. Bierbaum
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215
| | - Mark R. Nimlos
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215
| | - G. Barney Ellison
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado 80309-0215
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Ellison GB, Herbert JM, McCoy AB, Stanton JF, Szalay PG. Unimolecular Rearrangement oftrans-FONO to FNO2. A Possible Model System for Atmospheric Nitrate Formation†. J Phys Chem A 2004. [DOI: 10.1021/jp047220+] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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