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The role of predissociation states in the UV photooxidation of acetylene. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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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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Zhang Y, Yuan K, Yu S, Parker DH, Yang X. Photodissociation dynamics of acetylene via the C̃ Π1u electronic state. J Chem Phys 2010; 133:014307. [DOI: 10.1063/1.3456738] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Laruelle F, Boyé-Péronne S, Gauyacq D, Liévin J. Revisiting Mulliken’s Concepts about Rydberg States and Rydberg−Valence Interactions from Large-Scale Ab Initio Calculations on the Acetylene Molecule. J Phys Chem A 2009; 113:13210-20. [DOI: 10.1021/jp903948k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fabrice Laruelle
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
| | - Séverine Boyé-Péronne
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
| | - Dolores Gauyacq
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
| | - Jacques Liévin
- Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles, Cpi 160/09, 50 Av. F.D. Roosevelt, B-1050 Bruxelles, Belgium, and Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Université Paris-Sud 11, Bât. 210, F-91405 Orsay Cédex, France
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Hu YH, Zhen C, Dai JH, Zhou XG, Liu SL. High-resolution Absorption Spectra of Acetylene in 142.8152.3 nm. CHINESE J CHEM PHYS 2008. [DOI: 10.1088/1674-0068/21/05/415-420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Matthíasson K, Wang H, Kvaran Á. (2+n) REMPI of acetylene: Gerade Rydberg states and photorupture channels. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.04.104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Alnama K, Boyé-Péronne S, Douin S, Innocenti F, O'Reilly J, Roche AL, Shafizadeh N, Zuin L, Gauyacq D. Photolysis of allene and propyne in the 7–30eV region probed by the visible fluorescence of their fragments. J Chem Phys 2007; 126:044304. [PMID: 17286467 DOI: 10.1063/1.2430707] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The photolysis of allene and propyne, two isomers of C(3)H(4), has been investigated in the excitation energy range of 7-30 eV using vacuum ultraviolet synchrotron radiation. The visible fluorescence excitation spectra of the excited neutral photofragments of both isomers were recorded within the same experimental conditions. Below the first ionization potential (IP), this fluorescence was too weak to be dispersed and possibly originated from C(2)H or CH(2) radicals. Above IP, three excited photofragments have been characterized by their dispersed emission spectra: the CH radical (A (2)Delta-X (2)Pi), the C(2) radical (d (3)Pi(g)-a (3)Pi(u), "Swan's bands"), and the H atom (4-2 and 3-2 Balmer lines). A detailed analysis of the integrated emission intensities allowed us to determine several apparition thresholds for these fragments, all of them being interpreted as rapid and barrierless dissociation processes on the excited potential energy surfaces. In the low energy range explored in this work, both isomers exhibit different intensity distributions in their fragment emission as a function of the photolysis energy, indicating that mutual allene<-->propyne isomerization is not fully completed before dissociation occurs. The effect of isomerization on the dissociation into excited fragments is present in the whole excitation energy range albeit less important in the 7-16 eV region; it gradually increases with increasing excitation energy. Above 19 eV, the fragment distribution is very similar for the two isomers.
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Affiliation(s)
- Koutayba Alnama
- Laboratoire de Photophysique Moléculaire, CNRS UPR 3361, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cedex, France
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Arrowsmith AN, Chikan V, Leone SR. Dynamics of the CH(A2Delta) product from the reaction of C2H with O2 studied by Fourier transform visible spectroscopy. J Phys Chem A 2006; 110:7521-6. [PMID: 16774192 DOI: 10.1021/jp061246e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction C(2)H + O(2) --> CH(A(2)Delta) + CO(2) is investigated using Fourier transform visible emission spectroscopy. C(2)H radicals, produced by 193 nm photolysis of C(2)H(2), react with O(2) molecules at low total pressures to produce electronically excited CH(A(2)Delta). Observation of the CH(A(2)Delta-X(2)Pi) electronic emission to infer nascent rotational and vibrational CH(A(2)Delta) distributions provides information about energy partitioning in the CH(A(2)Delta) fragment during the reaction. The rotational and vibrational populations of the CH(A(2)Delta) product are determined by fitting the rotationally resolved experimental spectra with simulated spectra. The CH(A(2)Delta) product is found to be rotationally and vibrationally excited with T(rot) congruent with 1150 K and T(vib) congruent with 1900 K. The mechanism for this reaction proceeds through one of two five-atom intermediates and requires a crossing between electronic potential surfaces. The rotational excitation suggests a bent geometry for the final intermediate of this reaction before dissociation to products, and the vibrational excitation involves an elongation of the C-H bond from the compressed transition state to the final CH(A) state.
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Affiliation(s)
- Alan N Arrowsmith
- Department of Chemistry and Biochemistry, JILA, National Institute of Standards and Technology, University of Colorado, Boulder, Colorado 80309, USA
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Alnama K, Boyé S, Douin S, Innocenti F, O'Reilly J, Roche AL, Shafizadeh N, Zuin L, Gauyacq D. Neutral excited radicals formed by ethylene photodissociation in the 8–24 eV region. Phys Chem Chem Phys 2004. [DOI: 10.1039/b316056d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Zamith S, Blanchet V, Girard B, Andersson J, Sorensen SL, Hjelte I, Björneholm O, Gauyacq D, Norin J, Mauritsson J, L’Huillier A. The predissociation of highly excited states in acetylene by time-resolved photoelectron spectroscopy. J Chem Phys 2003. [DOI: 10.1063/1.1589479] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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O’Reilly J, Douin S, Boyé S, Shafizadeh N, Gauyacq D. Production of electronically excited CH via the vacuum ultraviolet photodissociation of ethylene and the possible role of the ethylidene isomer. J Chem Phys 2003. [DOI: 10.1063/1.1578995] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Kono M, Hoshina K, Yamanouchi K. Photofragment emission yield spectroscopy of acetylene in the D̃ 1Πu, Ẽ 1A, and F̃ 1Σu+ states by vacuum ultraviolet and infrared vacuum ultraviolet double-resonance laser excitations. J Chem Phys 2002. [DOI: 10.1063/1.1485064] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Boyé S, Campos A, Douin S, Fellows C, Gauyacq D, Shafizadeh N, Halvick P, Boggio-Pasqua M. Visible emission from the vibrationally hot C2H radical following vacuum-ultraviolet photolysis of acetylene: Experiment and theory. J Chem Phys 2002. [DOI: 10.1063/1.1471239] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Campos A, Boyé S, Douin S, Fellows C, Fillion JH, Shafizadeh N, Gauyacq D. The 5s−4d Rydberg States of C2H2 and C2D2 Studied by Resonant Multiphoton Ionization and Synchrotron Radiation: Structure and Stability. J Phys Chem A 2001. [DOI: 10.1021/jp0115392] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Campos
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
| | - S. Boyé
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
| | - S. Douin
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
| | - C. Fellows
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
| | - J. H. Fillion
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
| | - N. Shafizadeh
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
| | - D. Gauyacq
- Laboratoire de Photophysique Moléculaire, Bâtiment 210, Université de Paris-Sud, 91405 Orsay Cédex, France, Instituto de Fisica, Universidade Federal Fluminense, Niteroi, Rio de Janeiro, Brazil, and Université de Cergy-Pontoise, 95806 Cergy Cédex, France
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