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Khomenko E. Spin-Orbit Coupling Effects in BrO- and HOBr Photodissociation Reactions. CHEMISTRY & CHEMICAL TECHNOLOGY 2014. [DOI: 10.23939/chcht08.02.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Gross CBM, Dillon TJ, Schuster G, Lelieveld J, Crowley JN. Direct kinetic study of OH and O3 formation in the reaction of CH3C(O)O2 with HO2. J Phys Chem A 2014; 118:974-85. [PMID: 24491030 DOI: 10.1021/jp412380z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction between HO2 and CH3C(O)O2 has three exothermic product channels, forming OH (R3a), peracetic acid (R3b), and acetic acid plus O3 (R3c). The branching ratios of the OH- and ozone-forming reaction channels were determined using a combination of laser-induced fluorescence (LIF, for time-resolved OH concentration measurement) and transient absorption spectroscopy (TAS, for time-resolved O3 concentration measurement) following pulsed laser generation of HO2 and CH3C(O)O2 from suitable precursors. TAS was also used to determine the initial concentration of the reactant peroxy radicals. The data were evaluated by numerical simulation using kinetic models of the measured concentration profiles; a Monte Carlo approach was used to estimate the uncertainties of the rate constants (k3) and branching ratios (α) thus obtained. The reaction channel forming OH (R3a) was found to be the most important with α3a = 0.61 ± 0.09 and α3c = 0.16 ± 0.08. The overall rate coefficient of the title reaction was found to be k3 = (2.1 ± 0.4) × 10(-11) cm(3) molecule(-1) s(-1) for both HO2 and DO2. Use of DO2 resulted in an increase in α3a to 0.80 ± 0.14. Comparison with former studies shows that OH formation via (R3) has been underestimated significantly to date. Possible reasons for these discrepancies and atmospheric implications are discussed.
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Affiliation(s)
- C B M Gross
- Division of Atmospheric Chemistry, Max-Planck-Institut für Chemie , 55128 Mainz, Germany
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Tellinghuisen J. Least-squares analysis of overlapped bound-free absorption spectra and predissociation data in diatomics: the C(1Πu) state of I2. J Chem Phys 2011; 135:054301. [PMID: 21823694 DOI: 10.1063/1.3616039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Absorption spectra are recorded at low resolution but high quantitative precision for I(2) vapor at 35 °C and 64 °C. These and literature spectra are analyzed by least-squares quantum spectral simulation of the overlapped A ← X, B ← X, and C((1)Π(u)) ← X transitions, with the aid of a pseudocontinuum model for the discrete regions of the A ← X and B ← X spectra. The analysis yields improved descriptions of the small-R regions of the A- and B-state potentials, which are known precisely at larger R from discrete spectroscopy. The C potential is determined at small R from its C ← X absorption, at intermediate R from literature data for B → C predissociation, and at large R from its known van der Waals well. The estimates of the electronic transition moment function ∣μ(e)(R)∣ for the B-X transition expand upon precise results from a recent determination by a different method. For the C-X and A-X transitions, the R-dependence of the transition moment functions resembles that found previously for these systems in Br(2). Of the spectroscopic properties, the C ← X spectrum is most altered from the previous analysis, being now ∼20% weaker. For B → C predissociation, no derived C potential has yielded computed rates in adequate statistical agreement with the analyzed experimental data.
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Affiliation(s)
- Joel Tellinghuisen
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.
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Khamaganov V, Karunanandan R, Rodriguez A, Crowley JN. Photolysis of CH3C(O)CH3 (248 nm, 266 nm), CH3C(O)C2H5 (248 nm) and CH3C(O)Br (248 nm): pressure dependent quantum yields of CH3 formation. Phys Chem Chem Phys 2007; 9:4098-113. [PMID: 17687461 DOI: 10.1039/b701382e] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of CH(3) in the 248 or 266 nm photolysis of acetone (CH(3)C(O)CH(3)), 2-butanone (methylethylketone, MEK, CH(3)C(O)C(2)H(5)) and acetyl bromide (CH(3)C(O)Br) was examined using the pulsed photolytic generation of the radical and its detection by transient absorption spectroscopy at 216.4 nm. Experiments were carried out at room temperature (298 +/- 3 K) and at pressures between approximately 5 and 1500 Torr N(2). Quantum yields for CH(3) formation were derived relative to CH(3)I photolysis at the same wavelength in back-to-back experiments. For acetone at 248 nm, the yield of CH(3) was greater than unity at low pressures (1.42 +/- 0.15 extrapolated to zero pressure) confirming that a substantial fraction of the CH(3)CO co-product can dissociate to CH(3) + CO under these conditions. At pressures close to atmospheric the quantum yield approached unity, indicative of almost complete collisional relaxation of the CH(3)CO radical. Measurements of increasing CH(3)CO yield with pressure confirmed this. Contrasting results were obtained at 266 nm, where the yields of CH(3) (and CH(3)CO) were close to unity (0.93 +/- 0.1) and independent of pressure, strongly suggesting that nascent CH(3)CO is insufficiently activated to decompose on the time scales of these experiments at 298 K. In the 248 nm photolysis of CH(3)C(O)Br, CH(3) was observed with a pressure independent quantum yield of 0.92 +/- 0.1 and CH(3)CO remained below the detection limit, suggesting that CH(3)CO generated from CH(3)COBr photolysis at 248 nm is too highly activated to be quenched by collision. Similar to CH(3)C(O)CH(3), the photolysis of CH(3)C(O)C(2)H(5) at 248 nm revealed pressure dependent yields of CH(3), decreasing from 0.45 at zero pressure to 0.19 at pressures greater than 1000 Torr with a concomitant increase in the CH(3)CO yield. As part of this study, the absorption cross section of CH(3) at 216.4 nm (instrumental resolution of 0.5 nm) was measured to be (4.27 +/- 0.2) x 10(-17) cm(2) molecule(-1) and that of C(2)H(5) at 222 nm was (2.5 +/- 0.6) x 10(-18) cm(2) molecule(-1). An absorption spectrum of gas-phase CH(3)C(O)Br (210-305 nm) is also reported for the first time.
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Affiliation(s)
- V Khamaganov
- Division of Atmospheric Chemistry, Max-Planck-Institut für Chemie, 55020 Mainz, Germany
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Braban CF, Adams JW, Rodriguez D, Cox RA, Crowley JN, Schuster G. Heterogeneous reactions of HOI, ICl and IBr on sea salt and sea salt proxies. Phys Chem Chem Phys 2007; 9:3136-48. [PMID: 17612737 DOI: 10.1039/b700829e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The heterogeneous chemistry of HOI, ICl and IBr on sea salt and sea salt proxies has been studied at 274 K using two experimental approaches: a wetted wall flow tube coupled to an electron impact mass spectrometer (WWFT-MS) and an aerosol flow tube (AFT) coupled to a differential mobility analyser (DMA) and a chemical ionisation mass spectrometer (CIMS). Uptake of all three title molecules into bulk aqueous halide salt films was rapid and controlled by gas phase diffusion. Uptake of HOI gave rise to gas-phase ICl and IBr, with the latter being the predominant product whenever Br(-) was present. Only partial release of IBr was observed due to high solubility of dihalogens in the film. ICl uptake gave the same yield of IBr as HOI uptake. Uptake of ICl on NaBr aerosol was accommodation limited with alpha = 0.018 +/- 0.004 and gas phase IBr product has a yield of 0.6 +/- 0.3. The results show that HOI can act as a catalyst for activation of bromine from sea-salt aerosols in the marine boundary layer, via the reactions: HOI(aq) + Cl + H--> ICl(aq) + H(2)O(l) and ICl(aq) + Br--> IBr(aq) + Cl.
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Affiliation(s)
- C F Braban
- Department of Chemistry, University of Cambridge, Lensfield Rd, Cambridge, UK
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Tucceri ME, Hölscher D, Rodriguez A, Dillon TJ, Crowley JN. Absorption cross section and photolysis of OIO. Phys Chem Chem Phys 2006; 8:834-46. [PMID: 16482325 DOI: 10.1039/b512702e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Pulsed laser photolysis combined with transient absorption spectroscopy and resonance fluorescence was used to examine the photolysis of OIO at a number of wavelengths corresponding to absorption bands in its visible spectrum between approximately 530 and 570 nm. Photolysis at 532 nm was found to result in substantial depopulation of the absorbing ground state, enabling an estimate for the absorption cross section of OIO at 610.2 nm of (6 +/- 2) x 10(-18) cm2 molecule(-1) to be obtained. No evidence was found for I atom formation following photolysis of OIO at 532, 562.3, 567.9 and 573.8 nm, enabling an upper limit to the I atom quantum yield of < 0.05 (560-580 nm) and < 0.24 (532 nm) to be established.
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Affiliation(s)
- M E Tucceri
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Germany
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Riffault V, Bedjanian Y, Poulet G. Kinetic and mechanistic study of the reactions of OH with IBr and HOI. J Photochem Photobiol A Chem 2005. [DOI: 10.1016/j.jphotochem.2005.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nakano Y, Enami S, Nakamichi S, Aloisio S, Hashimoto S, Kawasaki M. Temperature and Pressure Dependence Study of the Reaction of IO Radicals with Dimethyl Sulfide by Cavity Ring-Down Laser Spectroscopy. J Phys Chem A 2003. [DOI: 10.1021/jp0345147] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Yukio Nakano
- Department of Molecular Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Shinichi Enami
- Department of Molecular Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Shinji Nakamichi
- Department of Molecular Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Simone Aloisio
- Department of Molecular Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Satoshi Hashimoto
- Department of Molecular Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Masahiro Kawasaki
- Department of Molecular Engineering, Kyoto University, Kyoto 606-8501, Japan
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Minaev B, Loboda O, Vahtras O, Agren H, Bilan E. Physical properties and spectra of IO, IO- and HOI studied by ab initio methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2002; 58:1039-1053. [PMID: 11942391 DOI: 10.1016/s1386-1425(01)00580-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Structure and properties of the IO, IO- and HOI species, which are of potential importance for the ozone destruction catalytic cycle in the troposphere, have been calculated together with the EPR, NMR and UV-visible spectra by ab initio methodology with account of spin-orbit coupling (SOC) effects. Multi-configuration self-consistent field calculations with linear and quadratic response techniques and the multi-reference configuration interaction method have been employed. Photodissociation of these species, crucial for the catalytic ozone-destruction cycle, is critically reviewed and analyzed. Calculations predict that the singlet-triplet (S-T) transition to the lowest triplet state (X1 A' --> 3A'') should be responsible for the weak long-wavelength tail absorption (approximately 450-560 nm) and photodissociation of the HOI molecule. The second, more intense, band around 400 nm is produced by two overlapping S-S and S-T transitions. In order to check this assignment of the HOI photodissociation the isoelectronic IO- anion and IO radical have been studied by the same methods. Comparison with the EPR spectrum of the IO radical indicates that the methods are reliable which gives credit to the accuracy of the HOI spectral interpretation. NMR spectra of HOI and IO- molecules and some other properties are calculated for the first time.
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Affiliation(s)
- Boris Minaev
- Laboratory of Theoretical Chemistry, Royal Institute of Technology, Stockholm, Sweden
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McFiggans G. Active chlorine release from marine aerosols: Roles for reactive iodine and nitrogen species. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jd000383] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Carl SA, Ingham T, Moortgat GK, Crowley JN. OH kinetics and photochemistry of HNO3 in the presence of water vapor. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00468-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Affiliation(s)
- Juliane C. Mössinger
- Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U. K
| | - R. Anthony Cox
- Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, U. K
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Ingham T, Cameron M, Crowley JN. Photodissociation of IO (355 nm) and OIO (532 nm): Quantum Yields for O(3P) and I(2PJ) Production. J Phys Chem A 2000. [DOI: 10.1021/jp001166p] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Trevor Ingham
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - Melanie Cameron
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - John N. Crowley
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
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Ingham T, Bauer D, Sander R, Crutzen PJ, Crowley JN. Kinetics and Products of the Reactions BrO + DMS and Br + DMS at 298 K. J Phys Chem A 1999. [DOI: 10.1021/jp9905979] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Trevor Ingham
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - Dieter Bauer
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - Rolf Sander
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - Paul J. Crutzen
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - John N. Crowley
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
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Allanic A, Rossi MJ. Heterogeneous reactions of HOI on substrates of atmospheric importance. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jd900285] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Campuzano-Jost P, Crowley JN. Kinetics of the Reaction of OH with HI between 246 and 353 K. J Phys Chem A 1999. [DOI: 10.1021/jp984321x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- P. Campuzano-Jost
- Max-Planck-Institut für Chemie Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
| | - J. N. Crowley
- Max-Planck-Institut für Chemie Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany
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Ingham T, Bauer D, Landgraf J, Crowley JN. Ultraviolet−Visible Absorption Cross Sections of Gaseous HOBr. J Phys Chem A 1998. [DOI: 10.1021/jp980272c] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Trevor Ingham
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, P.O. Box 3060, 55020 Mainz, Germany
| | - Dieter Bauer
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, P.O. Box 3060, 55020 Mainz, Germany
| | - Jochen Landgraf
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, P.O. Box 3060, 55020 Mainz, Germany
| | - John N. Crowley
- Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, P.O. Box 3060, 55020 Mainz, Germany
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