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Hansen K, Ferrari P. Vibrational angular momentum level densities of linear molecules. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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2
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Jiang J, Du Z, Liévin J, Field RW. One-colour (∼220 nm) resonance-enhanced (S 1 − S 0) multi-photon dissociation of acetylene: probe of the C 2 A1 Π u − X1 Σ +g band by frequency-modulation spectroscopy. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1724340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Jun Jiang
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Zhenhui Du
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, People's Republic of China
| | - Jacques Liévin
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Robert W. Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
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Photodissociation transition states characterized by chirped pulse millimeter wave spectroscopy. Proc Natl Acad Sci U S A 2020; 117:146-151. [PMID: 31852828 DOI: 10.1073/pnas.1911326116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 193-nm photolysis of CH2CHCN illustrates the capability of chirped-pulse Fourier transform millimeter-wave spectroscopy to characterize transition states. We investigate the HCN, HNC photofragments in highly excited vibrational states using both frequency and intensity information. Measured relative intensities of J = 1-0 rotational transition lines yield vibrational-level population distributions (VPD). These VPDs encode the properties of the parent molecule transition state at which the fragment molecule was born. A Poisson distribution formalism, based on the generalized Franck-Condon principle, is proposed as a framework for extracting information about the transition-state structure from the observed VPD. We employ the isotopologue CH2CDCN to disentangle the unimolecular 3-center DCN elimination mechanism from other pathways to HCN. Our experimental results reveal a previously unknown transition state that we tentatively associate with the HCN eliminated via a secondary, bimolecular reaction.
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4
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Ashfold MNR, Ingle RA, Karsili TNV, Zhang J. Photoinduced C–H bond fission in prototypical organic molecules and radicals. Phys Chem Chem Phys 2019; 21:13880-13901. [DOI: 10.1039/c8cp07454b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We survey and assess current knowledge regarding the primary photochemistry of hydrocarbon molecules and radicals.
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Affiliation(s)
| | | | | | - Jingsong Zhang
- Department of Chemistry
- University of California at Riverside
- Riverside
- USA
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5
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Jiang J, Saladrigas CA, Erickson TJ, Keenan CL, Field RW. Probing the predissociated levels of the S 1 state of acetylene via H-atom fluorescence and photofragment fluorescence action spectroscopy. J Chem Phys 2018; 149:174309. [PMID: 30408969 DOI: 10.1063/1.5045046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report two new experimental schemes to obtain rotationally resolved high-resolution spectra of predissociated S1 acetylene levels in the 47 000-47 300 cm-1 energy region (∼1200 cm-1 above the predissociation threshold). The two new detection schemes are compared to several other detection schemes (employed at similar laser power, molecular beam temperature, and number of signal averages) that have been used in our laboratory to study predissociated S1 acetylene levels, both in terms of the signal-to-noise ratio (S/N) of the resultant spectra and experimental simplicity. In the first method, H-atoms from the predissociated S1 acetylene levels are probed by two-photon laser-induced fluorescence (LIF). The H-atoms are pumped to the 3d level by the two-photon resonance transition at 205.14 nm. The resulting 3d-2p fluorescence (654.5 nm) is collected by a photomultiplier. The S/N of the H-atom fluorescence action spectrum is consistently better by ∼3× than that of the more widely used H-atom resonance-enhanced multiphoton ionization (REMPI) detection. Laser alignment is also considerably easier in H-atom fluorescence detection than H-atom REMPI detection due to the larger number-density of molecules that can be used in fluorescence vs. REMPI detection schemes. In the second method, fluorescence from electronically excited C2 and C2H photofragments of S1 acetylene is detected. In contrast to the H-atom detection schemes, the detected C2 and C2H photofragments are produced by the same UV laser as is used for the à - X ̃ acetylene excitation. As a result, laser alignment is greatly simplified for the photofragment fluorescence detection scheme, compared to both H-atom detection schemes. Using the photofragment fluorescence detection method, we are able to obtain action spectra of predissociated S1 acetylene levels with S/N ∼2× better than the HCCH REMPI detection and ∼10× better than H-atom and HCCH LIF detection schemes.
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Affiliation(s)
- Jun Jiang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Catherine A Saladrigas
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Trevor J Erickson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Clare L Keenan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Robert W Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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6
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Robertson C, Worth GA. Modelling the vibrationally mediated photo-dissociation of acetylene. Phys Chem Chem Phys 2017; 19:29483-29497. [DOI: 10.1039/c7cp05684b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A ten state vibronic coupling Hamiltonian is constructed for acetylene and used to simulate vibrationally mediated dissociation experiments.
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7
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Abstract
Transient diode laser absorption spectroscopy has been used to measure three strong vibronic bands in the near infrared spectrum of the C2H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a (2)Σ(+) state at 6696 cm(-1), a second (2)Σ(+) state at 7088 cm(-1), and a (2)Π state at 7110 cm(-1). By comparison with published calculations [R. Tarroni and S. Carter, J. Chem. Phys 119, 12878 (2003); Mol. Phys. 102, 2167 (2004)], the vibronic character of these levels was also assigned. The observed states contain both X(2)Σ(+) and A(2)Π electronic characters. Several local rotational level perturbations were observed in the excited states. Kinetic measurements of the time-evolution of the ground state populations following collisional relaxation and reactive loss of the radicals formed in a hot, non-thermal, population distribution were made using some of the strong rotational lines observed. The case of C2H may be a good place to investigate the behavior at intermediate pressures of inert colliders, where the competition between relaxation and reaction can be tuned and observed to compare with master equation models, rather than deliberately suppressed to measure thermal rate constants.
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Affiliation(s)
- Anh T Le
- Department of Energy and Photon Sciences, Division of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - Gregory E Hall
- Department of Energy and Photon Sciences, Division of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - Trevor J Sears
- Department of Energy and Photon Sciences, Division of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
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8
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Krechkivska O, Bacskay GB, Welsh BA, Nauta K, Kable SH, Stanton JF, Schmidt TW. The ionization energy of C2. J Chem Phys 2016; 144:144305. [DOI: 10.1063/1.4944932] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- O. Krechkivska
- School of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - G. B. Bacskay
- School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - B. A. Welsh
- School of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - K. Nauta
- School of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - S. H. Kable
- School of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - J. F. Stanton
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA
| | - T. W. Schmidt
- School of Chemistry, UNSW Sydney, Sydney, New South Wales 2052, Australia
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9
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Changala PB, Baraban JH, Merer AJ, Field RW. Probing cis-trans isomerization in the S1 state of C2H2 via H-atom action and hot band-pumped IR-UV double resonance spectroscopies. J Chem Phys 2015; 143:084310. [PMID: 26328846 DOI: 10.1063/1.4929588] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We report novel experimental strategies that should prove instrumental in extending the vibrational and rotational assignments of the S1 state of acetylene, C2H2, in the region of the cis-trans isomerization barrier. At present, the assignments are essentially complete up to ∼500 cm(-1) below the barrier. Two difficulties arise when the assignments are continued to higher energies. One is that predissociation into C2H + H sets in roughly 1100 cm(-1) below the barrier; the resulting quenching of laser-induced fluorescence (LIF) reduces its value for recording spectra in this region. The other difficulty is that tunneling through the barrier causes a staggering in the K-rotational structure of isomerizing vibrational levels. The assignment of these levels requires data for K values up to at least 3. Given the rotational selection rule K' - ℓ('') = ± 1, such data must be obtained via excited vibrational levels of the ground state with ℓ('') > 0. In this paper, high resolution H-atom resonance-enhanced multiphoton ionization spectra are demonstrated to contain predissociated bands which are almost invisible in LIF spectra, while preliminary data using a hyperthermal pulsed nozzle show that ℓ('') = 2 states can be selectively populated in a jet, giving access to K' = 3 states in IR-UV double resonance.
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Affiliation(s)
- P Bryan Changala
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Joshua H Baraban
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Anthony J Merer
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Robert W Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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10
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Zhu X, Yarkony DR. Quasi-diabatic representations of adiabatic potential energy surfaces coupled by conical intersections including bond breaking: A more general construction procedure and an analysis of the diabatic representation. J Chem Phys 2012; 137:22A511. [DOI: 10.1063/1.4734315] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Fárník M, Poterya V, Kočišek J, Fedor J, Slavíček P. Short review on the acetylene photochemistry in clusters: photofragment caging and reactivity. Mol Phys 2012. [DOI: 10.1080/00268976.2012.706389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Michal Fárník
- a J. Heyrovský Institute of Physical Chemistry v.v.i , Academy of Sciences of the Czech Republic , Dolejškova 3, 18223 Prague , Czech Republic
| | - Viktoriya Poterya
- a J. Heyrovský Institute of Physical Chemistry v.v.i , Academy of Sciences of the Czech Republic , Dolejškova 3, 18223 Prague , Czech Republic
| | - Jaroslav Kočišek
- a J. Heyrovský Institute of Physical Chemistry v.v.i , Academy of Sciences of the Czech Republic , Dolejškova 3, 18223 Prague , Czech Republic
- b Faculty of Mathematics and Physics , Charles University Prague , Czech Republic
| | - Juraj Fedor
- a J. Heyrovský Institute of Physical Chemistry v.v.i , Academy of Sciences of the Czech Republic , Dolejškova 3, 18223 Prague , Czech Republic
| | - Petr Slavíček
- c Department of Physical Chemistry , Institute of Chemical Technology Prague , Technická 5, 16628 Prague 6 , Czech Republic
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12
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Zhu X, Ma J, Yarkony DR, Guo H. Computational determination of theÃstate absorption spectrum of NH3and of ND3using a new quasi-diabatic representation of the X̃ andÃstates and full six-dimensional quantum dynamics. J Chem Phys 2012; 136:234301. [DOI: 10.1063/1.4725496] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Bittinger KL, Virgo WL, Field RW. Spectral Signatures of Inter-System Crossing Mediated by Energetically Distant Doorway Levels: Examples from the Acetylene S1 State. J Phys Chem A 2011; 115:11921-43. [DOI: 10.1021/jp2037894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kyle L. Bittinger
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Wilton L. Virgo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Robert W. Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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14
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Swinnen S, Elsamra RM, Nguyen VS, Peeters J, Carl SA, Nguyen MT. Theoretical and experimental investigation of the C2H+SO2 reaction over the range T=295–800K. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.07.098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Orr BJ. Spectroscopy and energetics of the acetylene molecule: dynamical complexity alongside structural simplicity. INT REV PHYS CHEM 2010. [DOI: 10.1080/01442350600892577] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Brian J. Orr
- a Department of Physics and Centre for Lasers and Applications , Macquarie University , Sydney , NSW 2109 , Australia
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16
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Ashfold MNR, King GA, Murdock D, Nix MGD, Oliver TAA, Sage AG. πσ* excited states in molecular photochemistry. Phys Chem Chem Phys 2010; 12:1218-38. [DOI: 10.1039/b921706a] [Citation(s) in RCA: 274] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Fárník M, Poterya V, Votava O, Ončák M, Slavíček P, Dauster I, Buck U. Solvent-Induced Photostability of Acetylene Molecules in Clusters Probed by Multiphoton Dissociation. J Phys Chem A 2009; 113:7322-30. [DOI: 10.1021/jp811073j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | - Ingo Dauster
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany
| | - Udo Buck
- Max-Planck Institut für Dynamik and Selbstorganisation, Bunsenstrasse 10, D-37073 Göttingen, Germany
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18
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Steeves AH, Merer AJ, Bechtel HA, Beck AR, Field RW. Direct observation of the symmetric stretching modes ofÃ1Auacetylene by pulsed supersonic jet laser induced fluorescence. Mol Phys 2008. [DOI: 10.1080/00268970802353327] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Hockett P, King AK, Powis I, Reid KL. Complete determination of the photoionization dynamics of a polyatomic molecule. I. Experimental photoelectron angular distributions from ÃAu1 acetylene. J Chem Phys 2007; 127:154307. [DOI: 10.1063/1.2790442] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Carl SA, Vereecken L, Peeters J. Kinetic parameters for gas-phase reactions: experimental and theoretical challenges. Phys Chem Chem Phys 2007; 9:4071-84. [PMID: 17687459 DOI: 10.1039/b705505f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article aims to illustrate the added value provided to experimental kinetics investigations by complementary theoretical kinetics studies, using as examples (i) reactions of two major hydrocarbon flame radicals, HCCO and C(2)H, and (ii) reactions of several oxygenated organic compounds with hydroxyl radicals of interest to atmospheric chemistry. The first part, on HCCO and C(2)H kinetics, does not attempt to give an extensive literature review, but rather addresses some major experimental techniques, mainly specific ones, that have allowed a great part of the available reactivity databases on these two species to be established. For several key reactions, it is shown how potential energy surfaces and statistical rate predictions based thereon have provided insight into the molecular mechanisms and have allowed estimates of product distributions as well as reliable extrapolations of experimental rate coefficients and branching ratios to higher temperatures. The second part addresses current issues in atmospheric chemistry relating mainly to hydroxyl radical reactions with oxygenated organics, and focuses on the experimental characterization of the often unusual temperature dependence of their rate coefficients and on the theoretical rationalization thereof, through the formation of hydrogen-bonded pre-reactive complexes and resulting tunnelling-enhanced H-abstraction. Finally, the development of general structure-activity relationships for OH reactions with organics, H-abstractions as well as OH-additions for unsaturated compounds, is briefly discussed.
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Affiliation(s)
- S A Carl
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
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Hébrard E, Dobrijevic M, Bénilan Y, Raulin F. Photochemical kinetics uncertainties in modeling Titan’s atmosphere: A review. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2006. [DOI: 10.1016/j.jphotochemrev.2006.12.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Lau KC, Ng CY. Accurate ab initio predictions of ionization energies of hydrocarbon radicals: CH2, CH3, C2H, C2H3, C2H5, C3H3, and C3H5. J Chem Phys 2005; 122:224310. [PMID: 15974671 DOI: 10.1063/1.1926274] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ionization energies for methylene (CH2), methyl (CH3), ethynyl (C2H), vinyl (C2H3), ethyl (C2H5), propargyl (C3H3), and allyl (C3H5) radicals have been calculated by the wave-function-based ab initio CCSD(T)/CBS approach, which involves the approximation to the complete basis set (CBS) limit at the coupled-cluster level with single and double excitations plus a quasiperturbative triple excitation [CCSD(T)]. When it is appropriate, the zero-point vibrational energy correction, the core-valence electronic correction, the scalar relativistic effect correction, the diagonal Born-Oppenheimer correction, and the high-order correlation correction have also been made in these calculations. The comparison between the computed ionization energy (IE) values and the highly precise experimental IE values determined in previous pulsed field ionization-photoelectron (PFI-PE) studies indicates that the CCSD(T)/CBS method is capable of providing accurate IE predictions for these hydrocarbon radicals achieving error limits well within +/-10 meV. The benchmarking of the CCSD(T)/CBS IE predictions by the PFI-PE experimental results also lends strong support for the conclusion that the CCSD(T)/CBS approach with high-level energy corrections can serve as a valuable alternative for reliable IE determination of radicals, particularly for those radicals with very unfavorable Franck-Condon factors for photoionization transitions near their ionization thresholds.
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Affiliation(s)
- K-C Lau
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
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Carl SA, Nguyen HMT, Elsamra RMI, Nguyen MT, Peeters J. Pulsed laser photolysis and quantum chemical-statistical rate study of the reaction of the ethynyl radical with water vapor. J Chem Phys 2005; 122:114307. [PMID: 15836215 DOI: 10.1063/1.1861887] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The rate coefficient of the gas-phase reaction C(2)H + H(2)O-->products has been experimentally determined over the temperature range 500-825 K using a pulsed laser photolysis-chemiluminescence (PLP-CL) technique. Ethynyl radicals (C(2)H) were generated by pulsed 193 nm photolysis of C(2)H(2) in the presence of H(2)O vapor and buffer gas N(2) at 15 Torr. The relative concentration of C(2)H radicals was monitored as a function of time using a CH* chemiluminescence method. The rate constant determinations for C(2)H + H(2)O were k(1)(550 K) = (2.3 +/- 1.3) x 10(-13) cm(3) s(-1), k(1)(770 K) =(7.2 +/- 1.4) x 10(-13) cm(3) s(-1), and k(1)(825 K) = (7.7 +/- 1.5) x 10(-13) cm(3) s(-1). The error in the only other measurement of this rate constant is also discussed. We have also characterized the reaction theoretically using quantum chemical computations. The relevant portion of the potential energy surface of C(2)H(3)O in its doublet electronic ground state has been investigated using density functional theory B3LYP6-311 + + G(3df,2p) and molecular orbital computations at the unrestricted coupled-cluster level of theory that incorporates all single and double excitations plus perturbative corrections for the triple excitations, along with the 6-311 + + G(3df,2p) basis set [(U)CCSD(T)6-311 + + G(3df,2p)] and using UCCSD(T)6-31G(d,p) optimized geometries. Five isomers, six dissociation products, and sixteen transition structures were characterized. The results confirm that the hydrogen abstraction producing C(2)H(2)+OH is the most facile reaction channel. For this channel, refined computations using (U)CCSD(T)6-311 + + G(3df,2p)(U)CCSD(T)6-311 + + G(d,p) and complete-active-space second-order perturbation theory/complete-active-space self-consistent-field theory (CASPT2/CASSCF) [B. O. Roos, Adv. Chem. Phys. 69, 399 (1987)] using the contracted atomic natural orbitals basis set (ANO-L) [J. Almlof and P. R. Taylor, J. Chem. Phys.86, 4070 (1987)] were performed, yielding zero-point energy-corrected potential energy barriers of 17 kJ mol(-1) and 15 kJ mol(-1), respectively. Transition-state theory rate constant calculations, based on the UCCSD(T) and CASPT2/CASSCF computations that also include H-atom tunneling and a hindered internal rotation, are in perfect agreement with the experimental values. Considering both our experimental and theoretical determinations, the rate constant can best be expressed, in modified Arrhenius form as k(1)(T) = (2.2 +/- 0.1) x 10(-21)T(3.05) exp[-(376 +/- 100)T] cm(3) s(-1) for the range 300-2000 K. Thus, at temperatures above 1500 K, reaction of C(2)H with H(2)O is predicted to be one of the dominant C(2)H reactions in hydrocarbon combustion.
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Affiliation(s)
- Shaun A Carl
- Department of Chemistry, University of Leuven, Belgium.
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Carl SA, Elsamra RMI, Kulkarni RM, Nguyen HMT, Peeters J. No Barrier for the Gas-Phase C2H + NH3 Reaction. J Phys Chem A 2004. [DOI: 10.1021/jp0377580] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shaun A. Carl
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Rehab M. I. Elsamra
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Raviraj M. Kulkarni
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Hue M. T. Nguyen
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Jozef Peeters
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
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25
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Carl SA, Nguyen HMT, Nguyen MT, Peeters J. An experimental and theoretical study of the reaction of ethynyl radicals with nitrogen dioxide (HC≡C+NO2). J Chem Phys 2003. [DOI: 10.1063/1.1573192] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Yamakita N, Iwamoto S, Tsuchiya S. Predissociation of Excited Acetylene in the ÃAu State around the Adiabatic Dissociation Threshold as Studied by LIF and H-Atom Action Spectroscopy. J Phys Chem A 2003. [DOI: 10.1021/jp0217785] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Nami Yamakita
- Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
| | - Sayoko Iwamoto
- Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
| | - Soji Tsuchiya
- Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan
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Läuter A, Lee K, Jung K, Vatsa R, Mittal J, Volpp HR. Absolute primary H atom quantum yield measurements in the 193.3 and 121.6 nm photodissociation of acetylene. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)00625-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Qadiri RH, Feltham EJ, Cottrill EEH, Taniguchi N, Ashfold MNR. Near ultraviolet photodissociation of allene and propyne. J Chem Phys 2002. [DOI: 10.1063/1.1425834] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Bar I, Rosenwaks S. Controlling bond cleavage and probing intramolecular dynamics via photodissociation of rovibrationally excited molecules. INT REV PHYS CHEM 2001. [DOI: 10.1080/01442350110076484] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Affiliation(s)
- H Sato
- Laser Photochemistry Research Group, Department of Chemistry for Materials, Faculty of Engineering, Mi'e University, 1515 Kamihamacho, Tsu 514-8507, Japan.
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Mizoguchi M, Yamakita N, Tsuchiya S, Iwasaki A, Hoshina K, Yamanouchi K. IR−UV Double Resonance Spectroscopy of Acetylene in the ÃAu nν3‘+ν4‘ and nν3‘+ν6‘ (n = 2, 3) Ungerade Vibrational States. J Phys Chem A 2000. [DOI: 10.1021/jp001215y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chiang WY, Hsu YC. Fluorescence lifetimes and predissociation processes in the B̃ 2A′ state of CCH. J Chem Phys 2000. [DOI: 10.1063/1.481339] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tsuji K, Terauchi C, Shibuya K, Tsuchiya S. Trans–cis isomerization of acetylene in the Ã1Au state as studied by dispersed fluorescence spectroscopy. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00413-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Suzuki T, Hashimoto N. Predissociation of acetylene from the à 1Au state studied by absorption, laser-induced fluorescence, and H-atom action spectroscopies. J Chem Phys 1999. [DOI: 10.1063/1.477868] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Löffler P, Wrede E, Schnieder L, Halpern JB, Jackson WM, Welge KH. Dissociation dynamics of acetylene Rydberg states as a function of excited state lifetime. J Chem Phys 1998. [DOI: 10.1063/1.477140] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Shi Y, Suzuki T. Formation of Metastable Triplet Acetylene from the Ã(1Au) State Near the Dissociation Threshold. J Phys Chem A 1998. [DOI: 10.1021/jp982275v] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yang Shi
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Toshinori Suzuki
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
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Taylor TR, Xu C, Neumark DM. Photoelectron spectra of the C2nH− (n=1–4) and C2nD− (n=1–3) anions. J Chem Phys 1998. [DOI: 10.1063/1.476462] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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