1
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Demireva M, Au K, Hansen N, Sheps L. Time-resolved quantification of key species and mechanistic insights in low-temperature tetrahydrofuran oxidation. Phys Chem Chem Phys 2024; 26:10357-10368. [PMID: 38502092 DOI: 10.1039/d3cp06227a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
We investigate the kinetics and report the time-resolved concentrations of key chemical species in the oxidation of tetrahydrofuran (THF) at 7500 torr and 450-675 K. Experiments are carried out using high-pressure multiplexed photoionization mass spectrometry (MPIMS) combined with tunable vacuum ultraviolet radiation from the Berkely Lab Advanced Light Source. Intermediates and products are quantified using reference photoionization (PI) cross sections, when available, and constrained by a global carbon balance tracking approach at all experimental temperatures simultaneously for the species without reference cross sections. From carbon balancing, we determine time-resolved concentrations for the ROO˙ and ˙OOQOOH radical intermediates, butanedial, and the combined concentration of ketohydroperoxide (KHP) and unsaturated hydroperoxide (UHP) products stemming from the ˙QOOH + O2 reaction. Furthermore, we quantify a product that we tentatively assign as fumaraldehyde, which arises from UHP decomposition via H2O or ˙OH + H loss. The experimentally derived species concentrations are compared with model predictions using the most recent literature THF oxidation mechanism of Fenard et al., (Combust. Flame, 2018, 191, 252-269). Our results indicate that the literature mechanism significantly overestimates THF consumption and the UHP + KHP concentration at our conditions. The model predictions are sensitive to the rate coefficient for the ROO˙ isomerization to ˙QOOH, which is the gateway for radical chain propagating and branching pathways. Comparisons with our recent results for cyclopentane (Demireva et al., Combust. Flame, 2023, 257, 112506) provide insights into the effect of the ether group on reactivity and highlight the need to determine accurate rate coefficients of ROO˙ isomerization and subsequent reactions.
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Affiliation(s)
- Maria Demireva
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
| | - Kendrew Au
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
| | - Nils Hansen
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
| | - Leonid Sheps
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
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2
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Chao W, Jones GH, Okumura M, Percival CJ, Winiberg FAF. Spectroscopic and Kinetic Studies of the ClSO Radical from Cl 2SO Photolysis. J Am Chem Soc 2022; 144:20323-20331. [DOI: 10.1021/jacs.2c07912] [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]
Affiliation(s)
- Wen Chao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California91125United States
| | - Gregory H. Jones
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California91125United States
| | - Mitchio Okumura
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California91125United States
| | - Carl J. Percival
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California91109-8099, United States
| | - Frank A. F. Winiberg
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California91109-8099, United States
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3
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Gierczak T, Papanastasiou DK, Burkholder JB. Reaction of Cl Atom with c-C 5F 8 and c-C 5HF 7: Relative and Absolute Measurements of Rate Coefficients and Identification of Degradation Products. J Phys Chem A 2022; 126:7737-7749. [PMID: 36242563 DOI: 10.1021/acs.jpca.2c05041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Partially and fully fluorinated olefins are a class of compounds with relatively short atmospheric lifetimes and low 100-year global warming potentials, compared to their saturated predecessors, which are used or considered as refrigerants, propellants, solvents, and other end-uses. The cyclic unsaturated compounds c-C5F8 and c-C5HF7 are currently under consideration as etching agents for the semiconductor industry. In this study, we expand on our previous work on the reaction of the OH radical with c-C5F8 and c-C5HF7 and report the rate coefficients, k, for the gas-phase reaction of the Cl atom with c-C5F8 and c-C5HF7 over a range of temperature (245-367 K) and pressure (100-200 Torr of He or N2 and 0 to 4.8 Torr O2) using a pulsed laser photolysis-resonance fluorescence (PLP-RF) technique. In addition, a relative rate (RR) technique, employing multiple reference compounds, was used to study the Cl atom reactions at 296 K, 100 and 630 Torr (N2 or air) total pressure. Reaction rate coefficients, k1, of the Cl atom reaction with c-C5F8 were found to be independent of pressure, over the pressure range used in this work, with k1(296 K), derived as an average of results from the PLP-RF and RR techniques being (1.07 ± 0.02) × 10-12 cm3 molecule-1 s-1 and k1(T) = (7.76 ± 0.73) × 10-13 × (exp[(98 ± 26)/T]) cm3 molecule-1 s-1, where the quoted error limits represent the 2σ data precision. Rate coefficients, k2, for the Cl atom + c-C5HF7 reaction were measured to be k2(296 K) = (4.61 ± 0.10) × 10-12 cm3 molecule-1 s-1 and k2(T) = (7.42 ± 0.89) × 10-13 × (exp[(540 ± 32)/T]) cm3 molecule-1 s-1. The Cl atom temporal profiles, observed with the PLP-RF technique, indicate that the Cl atom with c-C5F8 and c-C5HF7 reactions lead to adduct formation. The equilibrium constants for adduct formation were derived in this work, and a second-law analysis was used to obtain ΔH and ΔS values of -18.5 ± 0.4 kcal mol-1, -30.9 ± 1.2 cal K-1 mol-1, and -13.9 ± 0.5 kcal mol-1, -27.6 ± 1.1 cal K-1 mol-1 for the c-C5F8 and c-C5HF7 reactions, respectively. The Cl-initiated degradation of c-C5F8 and c-C5HF7 in the presence of O2 was studied and stable products were identified via infrared spectroscopy using experimental or theoretically derived spectra from our previous OH reaction work. For c-C5F8, FC(O)CF2CF2CF2C(O)F and FC(O)C(O)F were observed with molar yields of 0.80 and 0.10, respectively. For c-C5HF7, we observed the formation of HC(O)CF2CF2CF2C(O)F and HC(O)C(O)F with a combined molar yield of 0.72. Carbonyl difluoride, F2CO, was also a major product in the decomposition of c-C5F8 and c-C5HF7. The oxidation mechanism of the Cl-initiated degradation of c-C5F8 and c-C5HF7 is discussed. Based on the combined findings from this and our previous work, the atmospheric implications from the use of c-C5F8 and c-C5HF7 are presented.
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Affiliation(s)
- Tomasz Gierczak
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305-3328, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
| | - Dimitrios K Papanastasiou
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305-3328, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
| | - James B Burkholder
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305-3328, United States
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4
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Collin DE, Kovacic K, Light ME, Linclau B. Synthesis of Ortho-Functionalized 1,4-Cubanedicarboxylate Derivatives through Photochemical Chlorocarbonylation. Org Lett 2021; 23:5164-5169. [PMID: 34133174 DOI: 10.1021/acs.orglett.1c01702] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The cubane ring has received intense attention as a 3D benzene isostere and scaffold. Mono- and 1,4-disubstituted cubanes are well-described. Here we report a practical procedure for a direct radical-mediated chlorocarbonylation process initially reported by Bashir-Hashemi, to access a range of 2-substituted 1,4-cubanedicarboxylic ester derivatives. A subsequent regioselective ester hydrolysis to give fully differentiated 1,2,4-trisubstituted cubanes is demonstrated.
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Affiliation(s)
- Diego E Collin
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Kristina Kovacic
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Mark E Light
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Bruno Linclau
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
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5
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Sheps L, Dewyer AL, Demireva M, Zádor J. Quantitative Detection of Products and Radical Intermediates in Low-Temperature Oxidation of Cyclopentane. J Phys Chem A 2021; 125:4467-4479. [PMID: 34006098 DOI: 10.1021/acs.jpca.1c02001] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a combined experimental and theoretical investigation of the autoignition chemistry of a prototypical cyclic hydrocarbon, cyclopentane. Experiments using a high-pressure photolysis reactor coupled to time-resolved synchrotron VUV photoionization mass spectrometry directly probe the short-lived radical intermediates and products in cyclopentane oxidation reactions. We detect key peroxy radical intermediates ROO and OOQOOH, as well as several hydroperoxides, formed by second O2 addition. Automated quantum chemical calculations map out the R + O2 + O2 reaction channels and demonstrate that the detected intermediates belong to the dominant radical chain-branching pathway: ROO (+ O2) → γ-QOOH + O2 → γ-OOQOOH → products. ROO, OOQOOH, and hydroperoxide products of second-O2 addition undergo extensive dissociative ionization, making their experimental assignment challenging. We use photoionization dynamics calculations to aid in their characterization and report the absolute photoionization spectra of isomerically pure ROO and γ-OOQOOH. A global statistical fit of the observed kinetics enables reliable quantification of the time-resolved concentrations of these elusive, yet critical species, paving the way for detailed comparisons with theoretical predictions from master-equation-based models.
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Affiliation(s)
- Leonid Sheps
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Amanda L Dewyer
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Maria Demireva
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Judit Zádor
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
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6
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Savee JD, Sztáray B, Welz O, Taatjes CA, Osborn DL. Valence Photoionization and Autoionization of the Formyl Radical. J Phys Chem A 2021; 125:3874-3884. [PMID: 33929204 DOI: 10.1021/acs.jpca.1c01775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have used 308 nm photolysis of acetaldehyde to measure a photoionization spectrum of the formyl (HCO) radical between 8 and 11.5 eV using an 11 meV FWHM photoionization energy resolution. We have confirmed that the formyl radical is the carrier of the spectrum by generating an identical spectrum of the HCO product in the Cl + H2CO reaction. The spectrum of HCO and its deuterated isotopologue (DCO) have several resolved autoionizing resonances above the Franck-Condon envelope, which we assign to autoionization after initial excitation into neutral 3sσ and 3p Rydberg states converging to the first triplet excited state of HCO+(ã 3A'). The quantum defects for these states are δ3sσ = 1.06 ± 0.02 and δ3p = 0.821 ± 0.019. We report absolute photoionization cross-section measurements of σHCOPI(9.907 eV) = 4.5 ± 0.9 Mb, σHCOPI(10.007 eV) = 4.8 ± 1.0 Mb, σHCOPI(10.107 eV) = 6.0 ± 1.2 Mb, σHCOPI(10.107 eV) = 5.7 ± 1.2 Mb, and σHCOPI(10.304 eV) = 10.6 ± 2.2 Mb relative to the photoionization cross section of the methyl radical. The absolute cross-section measurements are a factor of ∼1.5 larger than those determined in past studies, although the presence of strong autoionizing features supports a dependence on photoionization energy resolution. We propose that the semiempirical model of Xu and Pratt for estimation of free radical photoionization cross sections is more accurate when applied with a reference species containing the same atoms as the free radical rather than isoelectronic species with different atoms.
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Affiliation(s)
- John D Savee
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States
| | - Bálint Sztáray
- Department of Chemistry, University of the Pacific, Stockton, California 95211, United States
| | - Oliver Welz
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States
| | - Craig A Taatjes
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States.,Department of Chemical Engineering, University of California, Davis, Davis, California 95616, United States
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7
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Chattopadhyay A, Gierczak T, Marshall P, Papadimitriou VC, Burkholder JB. Kinetic fall-off behavior for the Cl + Furan-2,5-dione (C 4H 2O 3, maleic anhydride) reaction. Phys Chem Chem Phys 2021; 23:4901-4911. [PMID: 33616582 DOI: 10.1039/d0cp06402e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rate coefficients, k, for the gas-phase Cl + Furan-2,5-dione (C4H2O3, maleic anhydride) reaction were measured over the 15-500 torr (He and N2 bath gas) pressure range at temperatures between 283 and 323 K. Kinetic measurements were performed using pulsed laser photolysis (PLP) to produce Cl atoms and atomic resonance fluorescence (RF) to monitor the Cl atom temporal profile. Complementary relative rate (RR) measurements were performed at 296 K and 620 torr pressure (syn. air) and found to be in good agreement with the absolute measurements. A Troe-type fall-off fit of the temperature and pressure dependence yielded the following rate coefficient parameters: ko(T) = (9.4 ± 0.5) × 10-29 (T/298)-6.3 cm6 molecule-2 s-1, k∞(T) = (3.4 ± 0.5) × 10-11 (T/298)-1.4 cm3 molecule-1 s-1. The formation of a Cl·C4H2O3 adduct intermediate was deduced from the Cl atom temporal profiles and an equilibrium constant, KP(T), for the Cl + C4H2O3 ↔ Cl·C4H2O3 reaction was determined. A third-law analysis yielded ΔH = -15.7 ± 0.4 kcal mol-1 with ΔS = -25.1 cal K-1 mol-1, where ΔS was derived from theoretical calculations at the B3LYP/6-311G(2d,p,d) level. In addition, the rate coefficient for the Cl·C4H2O3 + O2 reaction at 296 K was measured to be (2.83 ± 0.16) × 10-12 cm3 molecule-1 s-1, where the quoted uncertainty is the 2σ fit precision. Stable end-product molar yields of (83 ± 7), (188 ± 10), and (65 ± 10)% were measured for CO, CO2, and HC(O)Cl, respectively, in an air bath gas. An atmospheric degradation mechanism for C4H2O3 is proposed based on the observed product yields and theoretical calculations of ring-opening pathways and activation barrier energies at the CBS-QB3 level of theory.
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Affiliation(s)
- Aparajeo Chattopadhyay
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305-3327, USA. and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
| | - Tomasz Gierczak
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305-3327, USA. and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
| | - Paul Marshall
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305-3327, USA. and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA and Department of Chemistry and Center for Advanced Scientific Computing and Modeling, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203, USA
| | - Vassileios C Papadimitriou
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305-3327, USA. and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
| | - James B Burkholder
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305-3327, USA.
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8
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Absorption cross-section measurements of ortho-xylyl radical in the 460.1–475.1 nm region and investigation of its temperature and pressure dependence using cavity ringdown spectroscopy. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2020.138314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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9
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Demireva M, Au K, Sheps L. Direct time-resolved detection and quantification of key reactive intermediates in diethyl ether oxidation at T = 450-600 K. Phys Chem Chem Phys 2020; 22:24649-24661. [PMID: 33099590 DOI: 10.1039/d0cp03861j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-pressure multiplexed photoionization mass spectrometry (MPIMS) with tunable vacuum ultraviolet (VUV) ionization radiation from the Lawrence Berkeley Labs Advanced Light Source is used to investigate the oxidation of diethyl ether (DEE). Kinetics and photoionization (PI) spectra are simultaneously measured for the species formed. Several stable products from DEE oxidation are identified and quantified using reference PI cross-sections. In addition, we directly detect and quantify three key chemical intermediates: peroxy (ROO˙), hydroperoxyalkyl peroxy (˙OOQOOH), and ketohydroperoxide (HOOP[double bond, length as m-dash]O, KHP). These intermediates undergo dissociative ionization (DI) into smaller fragments, making their identification by mass spectrometry challenging. With the aid of quantum chemical calculations, we identify the DI channels of these key chemical species and quantify their time-resolved concentrations from the overall carbon atom balance at T = 450 K and P = 7500 torr. This allows the determination of the absolute PI cross-sections of ROO˙, ˙OOQOOH, and KHP into each DI channel directly from experiment. The PI cross-sections in turn enable the quantification of ROO˙, ˙OOQOOH, and KHP from DEE oxidation over a range of experimental conditions that reveal the effects of pressure, O2 concentration, and temperature on the competition among radical decomposition and second O2 addition pathways.
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Affiliation(s)
- Maria Demireva
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
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10
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McGillen MR, Papadimitriou VC, Smith SC, Burkholder JB. FC(O)C(O)F, FC(O)CF 2C(O)F, and FC(O)CF 2CF 2C(O)F: Ultraviolet and Infrared Absorption Spectra and 248 nm Photolysis Products. J Phys Chem A 2020; 124:7123-7133. [PMID: 32786981 DOI: 10.1021/acs.jpca.0c04607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Perfluorodicarbonyl (PFDC) compounds may be emitted directly into the atmosphere or formed in the atmospheric degradation of trace fluorinated gases, such as unsaturated perfluoro cyclic compounds. A potential atmospheric removal process for PFDCs is UV photolysis, which is presently not well-characterized. In this work, UV and infrared absorption spectra of FC(O)C(O)F, FC(O)CF2C(O)F, and FC(O)CF2CF2C(O)F (three of the simplest PFDCs) and their 248 nm photolysis products are reported. UV spectra were measured at 296 K between 190 and 320 nm using single wavelength and broadband diode array spectroscopic measurement techniques. Infrared absorption spectra were measured at 296 K using Fourier transform infrared spectroscopy between 500 and 4000 cm-1. The PFDCs are shown to be potent greenhouse gases with radiative efficiencies (well-mixed) of 0.142, 0.218, and 0.293 W m-2 ppb-1 for FC(O)C(O)F, FC(O)CF2C(O)F, and FC(O)CF2CF2C(O)F, respectively. Photolysis product yields (248 nm) were measured using pulsed laser photolysis combined with infrared absorption detection of radical products scavenged to stable bromides by reaction with Br2. BrC(O)F was identified as a major stable end product in all systems with a yield greater than ∼90%. The infrared spectrum of BrC(O)F is reported as part of this study. FC(O)CBrF2 and FC(O)CF2CBrF2 were also identified as products in the photolysis of FC(O)CF2C(O)F and FC(O)CF2CF2C(O)F, respectively, by comparison with theoretically calculated infrared absorption spectra. A carbonyl difluoride (CF2O) primary photolysis yield of ∼10% was measured in the photolysis of FC(O)C(O)F.
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Affiliation(s)
- Max R McGillen
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
| | - Vassileios C Papadimitriou
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
| | - Shona C Smith
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305, United States.,Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309, United States
| | - James B Burkholder
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305, United States
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11
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Eskola AJ, Blitz MA, Pilling MJ, Seakins PW, Shannon RJ. Time-Resolved Measurements and Master Equation Modelling of the Unimolecular Decomposition of CH 3OCH 2. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2020-0007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The rate coefficient for the unimolecular decomposition of CH3OCH2, k
1, has been measured in time-resolved experiments by monitoring the HCHO product. CH3OCH2 was rapidly and cleanly generated by 248 nm excimer photolysis of oxalyl chloride, (ClCO)2, in an excess of CH3OCH3, and an excimer pumped dye laser tuned to 353.16 nm was used to probe HCHO via laser induced fluorescence. k
1(T,p) was measured over the ranges: 573–673 K and 0.1–4.3 × 1018 molecule cm−3 with a helium bath gas. In addition, some experiments were carried out with nitrogen as the bath gas. Ab initio calculations on CH3OCH2 decomposition were carried out and a transition-state for decomposition to CH3 and H2CO was identified. This information was used in a master equation rate calculation, using the MESMER code, where the zero-point-energy corrected barrier to reaction, ΔE
0,1, and the energy transfer parameters, ⟨ΔEdown⟩ × T
n, were the adjusted parameters to best fit the experimental data, with helium as the buffer gas. The data were combined with earlier measurements by Loucks and Laidler (Can J. Chem.
1967, 45, 2767), with dimethyl ether as the third body, reinterpreted using current literature for the rate coefficient for recombination of CH3OCH2. This analysis returned ΔE
0,1 = (112.3 ± 0.6) kJ mol−1, and leads to
k
1
∞
(
T
)
=
2.9
×
10
12
$k_{1}^{\infty}(T)=2.9\times{10^{12}}$
(T/300)2.5 exp(−106.8 kJ mol−1/RT). Using this model, limited experiments with nitrogen as the bath gas allowed N2 energy transfer parameters to be identified and then further MESMER simulations were carried out, where N2 was the buffer gas, to generate k
1(T,p) over a wide range of conditions: 300–1000 K and N2 = 1012–1025 molecule cm−3. The resulting k
1(T,p) has been parameterized using a Troe-expression, so that they can be readily be incorporated into combustion models. In addition, k
1(T,p) has been parametrized using PLOG for the buffer gases, He, CH3OCH3 and N2.
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Affiliation(s)
- Arrke J. Eskola
- School of Chemistry , University of Leeds , Leeds LS2 9JT , UK
- Department of Chemistry , University of Helsinki , P.O. Box 55 (A.I. Virtasen aukio 1), FI-00014 Helsinki , Finland
| | - Mark A. Blitz
- School of Chemistry , University of Leeds , Leeds LS2 9JT , UK
- National Centre for Atmospheric Science , University of Leeds , Leeds LS2 9JT, UK
| | | | - Paul W. Seakins
- School of Chemistry , University of Leeds , Leeds LS2 9JT , UK
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12
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Whelan CA, Blitz MA, Shannon R, Onel L, Lockhart JP, Seakins PW, Stone D. Temperature and Pressure Dependent Kinetics of QOOH Decomposition and Reaction with O2: Experimental and Theoretical Investigations of QOOH Radicals Derived from Cl + (CH3)3COOH. J Phys Chem A 2019; 123:10254-10262. [DOI: 10.1021/acs.jpca.9b08785] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Mark A. Blitz
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Robin Shannon
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Lavinia Onel
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | | | - Paul W. Seakins
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Daniel Stone
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
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13
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Davis JC, Koritzke AL, Caravan RL, Antonov IO, Christianson MG, Doner AC, Osborn DL, Sheps L, Taatjes CA, Rotavera B. Influence of the Ether Functional Group on Ketohydroperoxide Formation in Cyclic Hydrocarbons: Tetrahydropyran and Cyclohexane. J Phys Chem A 2019; 123:3634-3646. [PMID: 30865470 DOI: 10.1021/acs.jpca.8b12510] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photolytically initiated oxidation experiments were conducted on cyclohexane and tetrahydropyran using multiplexed photoionization mass spectrometry to assess the impact of the ether functional group in the latter species on reaction mechanisms relevant to autoignition. Pseudo-first-order conditions, with [O2]0:[R•]0 > 2000, were used to ensure that R• + O2 → products were the dominant reactions. Quasi-continuous, tunable vacuum ultraviolet light from a synchrotron was employed over the range 8.0-11.0 eV to measure photoionization spectra of the products at two pressures (10 and 1520 Torr) and three temperatures (500, 600, and 700 K). Photoionization spectra of ketohydroperoxides were measured in both species and were qualitatively identical, within the limit of experimental noise, to those of analogous species formed in n-butane oxidation. However, differences were noted in the temperature dependence of ketohydroperoxide formation between the two species. Whereas the yield from cyclohexane is evident up to 700 K, ketohydroperoxides in tetrahydropyran were not detected above 650 K. The difference indicates that reaction mechanisms change due to the ether group, likely affecting the requisite •QOOH + O2 addition step. Branching fractions of nine species from tetrahydropyran were quantified with the objective of determining the role of ring-opening reactions in diminishing ketohydroperoxide. The results indicate that products formed from unimolecular decomposition of R• and •QOOH radicals via concerted C-C and C-O β-scission are pronounced in tetrahydropyran and are insignificant in cyclohexane oxidation. The main conclusion drawn is that, under the conditions herein, ring-opening pathways reduce the already low steady-state concentration of •QOOH, which in the case of tetrahydropyran prevents •QOOH + O2 reactions necessary for ketohydroperoxide formation. Carbon balance calculations reveal that products from ring opening of both R• and •QOOH, at 700 K, account for >70% at 10 Torr and >55% at 1520 Torr. Three pathways are confirmed to contribute to the depletion of •QOOH in tetrahydropyran including (i) γ-•QOOH → pentanedial + •OH, (ii) γ-•QOOH → vinyl formate + ethene + •OH, and (iii) γ-•QOOH → 3-butenal + formaldehyde + •OH. Analogous mechanisms in cyclohexane oxidation leading to similar intermediates are compared and, on the basis of mass spectral results, confirm that no such ring-opening reactions occur. The implication from the comparison to cyclohexane is that the ether group in tetrahydropyran increases the propensity for ring-opening reactions and inhibits the formation of ketohydroperoxide isomers that precede chain-branching. On the contrary, the absence of such reactions in cyclohexane enables ketohydroperoxide formation up to 700 K and perhaps higher temperature.
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Affiliation(s)
| | | | - Rebecca L Caravan
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - Ivan O Antonov
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | | | | | - David L Osborn
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - Leonid Sheps
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - Craig A Taatjes
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
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14
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Schleier D, Constantinidis P, Faßheber N, Fischer I, Friedrichs G, Hemberger P, Reusch E, Sztáray B, Voronova K. Kinetics of the a-C 3H 5 + O 2 reaction, investigated by photoionization using synchrotron radiation. Phys Chem Chem Phys 2018; 20:10721-10731. [PMID: 29340384 DOI: 10.1039/c7cp07893e] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The kinetics of the combustion-relevant reaction of the allyl radical, a-C3H5, with molecular oxygen has been studied in a flow tube reactor at the vacuum ultraviolet (VUV) beamline of the Swiss Light Source storage ring, using the CRF-PEPICO (Combustion Reactions Followed by Photoelectron Photoion Coincidence Spectroscopy) setup. The ability to measure threshold photoelectron spectra enables a background-free detection of reactive species as well as an isomer-specific analysis of reaction products. Allyl was generated by direct photodissociation of allyl iodide at 266 nm and 213 nm and indirectly by the reaction of propene with Cl atoms, which were generated by photolysis from oxalyl chloride at 266 nm. Experiments were conducted at room temperature at low pressures between 0.8 and 3 mbar using Ar as the buffer gas and with excess O2 to maintain nearly pseudo-first-order reaction conditions. Whereas allyl was detected by photoionisation using synchrotron radiation, the main reaction product allyl peroxy was not observed due to dissociative ionisation of this weakly bound species. From the concentration-time profiles of the allyl signal, second-order rate constants between 1.35 × 1011 cm3 mol-1 s-1 at 0.8 mbar and 1.75 × 1011 cm3 mol-1 s-1 at 3 mbar were determined. The rates obtained for the different allyl radical generation schemes agree well with each other, but are about a factor of 2 higher than the ones reported previously using He as a buffer gas. The discrepancy is partly attributed to the higher collision efficiency of Ar causing a varying fall-off behavior. When allyl is produced by the reaction of propene with Cl atom, an unexpected product is observed at m/z = 68, which was identified as 1,3-butadienal in the threshold photoelectron spectrum. It is formed in a secondary reaction of allyl with the OCCl radical, which is generated in the 266 nm photolysis of oxalyl chloride.
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Affiliation(s)
- D Schleier
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany.
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15
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Huang TK, Chen BJ, Lin KC, Lin L, Sun BJ, Chang AHH. Cl2 Elimination in 248 nm Photolysis of (COCl)2 Probed with Cavity Ring-Down Absorption Spectroscopy. J Phys Chem A 2017; 121:2888-2895. [DOI: 10.1021/acs.jpca.6b12810] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ting-Kang Huang
- Department of Chemistry, National Taiwan University,
and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
| | - Bo-Jung Chen
- Department of Chemistry, National Taiwan University,
and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
| | - King-Chuen Lin
- Department of Chemistry, National Taiwan University,
and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
| | - Lin Lin
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - Bing-Jian Sun
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - A. H. H. Chang
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
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16
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Chen LW, Hung CM, Matsui H, Lee YP. New experimental evidence to support roaming in the reaction Cl + isobutene (i-C 4H 8). Sci Rep 2017; 7:40105. [PMID: 28079173 PMCID: PMC5228202 DOI: 10.1038/srep40105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 11/30/2016] [Indexed: 12/05/2022] Open
Abstract
The reaction Cl + isobutene (i-C4H8) was reported by Suits et al. to proceed via, in addition to abstraction, an addition-elimination path following a roaming excursion of Cl; a near-zero translational energy release and an isotropic angular distribution observed at a small collision energy characterized this mechanism. We employed a new experimental method to further characterize this roaming mechanism through observation of the internal distribution of HCl (v, J) and their temporal behavior upon irradiation of a mixture of Cl2C2O2 and i-C4H8 in He or Ar buffer gas. With 1–3 Torr buffer gas added to approach the condition of small collision energy, the intensities of emission of HCl (v = 1, 2) and the HCl production rates increased significantly; Ar shows a more significant effect than He because Ar quenches Cl more efficiently to reduce the collisional energy and facilitate the roaming path. According to kinetic modeling, the rate of addition-elimination (roaming) increased from kE ≈ 2 × 105 s−1 when little buffer gas was present to ~1.9 × 106 s−1 when 2–3 Torr of Ar was added, and the branching ratio for formation of [HCl (v = 2)]/[HCl (v = 1)] increased from 0.02 ± 0.01 for abstraction to 0.06 ± 0.01 for roaming.
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Affiliation(s)
- Li-Wei Chen
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - Ching-Ming Hung
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - Hiroyuki Matsui
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan.,Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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17
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Antonov IO, Zádor J, Rotavera B, Papajak E, Osborn DL, Taatjes CA, Sheps L. Pressure-Dependent Competition among Reaction Pathways from First- and Second-O2 Additions in the Low-Temperature Oxidation of Tetrahydrofuran. J Phys Chem A 2016; 120:6582-95. [DOI: 10.1021/acs.jpca.6b05411] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ivan O. Antonov
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Judit Zádor
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Brandon Rotavera
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Ewa Papajak
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - David L. Osborn
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Craig A. Taatjes
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Leonid Sheps
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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18
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McKee K, Blitz MA, Pilling MJ. Temperature and Pressure Studies of the Reactions of CH3O2, HO2, and 1,2-C4H9O2 with NO2. J Phys Chem A 2015; 120:1408-20. [DOI: 10.1021/acs.jpca.5b06306] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kenneth McKee
- School of Chemistry and ‡National Centre
for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Mark A. Blitz
- School of Chemistry and ‡National Centre
for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Michael J. Pilling
- School of Chemistry and ‡National Centre
for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, United Kingdom
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19
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McGillen MR, Burkholder JB. Gas-phase photodissociation of CF3C(O)Cl between 193 and 280 nm. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.09.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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Welz O, Burke MP, Antonov IO, Goldsmith CF, Savee JD, Osborn DL, Taatjes CA, Klippenstein SJ, Sheps L. New Insights into Low-Temperature Oxidation of Propane from Synchrotron Photoionization Mass Spectrometry and Multiscale Informatics Modeling. J Phys Chem A 2015; 119:7116-29. [DOI: 10.1021/acs.jpca.5b01008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Oliver Welz
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Michael P. Burke
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60493, United States
- Department
of Mechanical Engineering, Department of Chemical Engineering and
Data Sciences Institute, Columbia University, New York, New York 10027, United States
| | - Ivan O. Antonov
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - C. Franklin Goldsmith
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60493, United States
| | - John D. Savee
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - David L. Osborn
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Craig A. Taatjes
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Stephen J. Klippenstein
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60493, United States
| | - Leonid Sheps
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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21
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Burkholder JB, Cox RA, Ravishankara AR. Atmospheric degradation of ozone depleting substances, their substitutes, and related species. Chem Rev 2015; 115:3704-59. [PMID: 25893463 DOI: 10.1021/cr5006759] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- James B Burkholder
- †Chemical Sciences Division, Earth System Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado 80305, United States
| | - R A Cox
- ‡Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EP, United Kingdom
| | - A R Ravishankara
- §Departments of Chemistry and Atmospheric Science, Colorado State University, 1872 Campus Delivery, Fort Collins, Colorado 80523, United States
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22
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Fang Q, Shen L, Fang WH. Synchronous concerted multiple-body photodissociation of oxalyl chloride explored by ab initio-based dynamics simulations. J Chem Phys 2014; 139:024310. [PMID: 23862946 DOI: 10.1063/1.4812783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Photo-induced multiple body dissociation is of fundamental interest in chemistry and physics. A description of the mechanism associated with n-body (n ≥ 3) photodissociation has proven to be an intriguing and yet challenging issue in the field of chemical dynamics. Oxalyl chloride, (ClCO)2, is the sole molecule reported up to date that can undergo four-body dissociation following absorption of a single UV photon, with a rich history of mechanistic debate. In the present work, the combined electronic structure calculations and dynamics simulations have been performed at the advanced level, which provides convincing evidence for resolving the mechanistic debate. More importantly, synchronous and asynchronous concertedness were explored for the first time for the (ClCO)2 photodissociation, which is based on the simulated time constants for the C-C and C-Cl bond fissions. Upon photoexcitation of (ClCO)2 to the S1 state, the adiabatic C-C or C-Cl fission takes place with little possibility. The four-body dissociation to 2Cl((2)P) and 2CO((1)Σ) was determined to a dominant channel with its branch of ∼0.7, while the three-body dissociation to ClCO((2)A(')) + CO((1)Σ) + Cl((2)P) was predicted to play a minor role in the (ClCO)2 photodissociation at 193 nm. Both the four-body and three-body dissociations are non-adiabatic processes, which proceed in a synchronous concerted way as a result of the S1 → S0 internal conversion. There is a little possibility for two-body dissociation to occur in the S0 and S1 states.
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Affiliation(s)
- Qiu Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
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23
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Lockhart J, Blitz M, Heard D, Seakins P, Shannon R. Kinetic Study of the OH + Glyoxal Reaction: Experimental Evidence and Quantification of Direct OH Recycling. J Phys Chem A 2013; 117:11027-37. [DOI: 10.1021/jp4076806] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- James Lockhart
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | - Mark Blitz
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- National
Centre for Atmospheric Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Dwayne Heard
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- National
Centre for Atmospheric Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Paul Seakins
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- National
Centre for Atmospheric Science, University of Leeds, Leeds LS2 9JT, U.K
| | - Robin Shannon
- School
of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
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24
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Papadimitriou VC, McGillen MR, Smith SC, Jubb AM, Portmann RW, Hall BD, Fleming EL, Jackman CH, Burkholder JB. 1,2-Dichlorohexafluoro-cyclobutane (1,2-c-C4F6Cl2, R-316c) a Potent Ozone Depleting Substance and Greenhouse Gas: Atmospheric Loss Processes, Lifetimes, and Ozone Depletion and Global Warming Potentials for the (E) and (Z) Stereoisomers. J Phys Chem A 2013; 117:11049-65. [DOI: 10.1021/jp407823k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vassileios C. Papadimitriou
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
- Laboratory
of Photochemistry and Chemical Kinetics, Department of Chemistry, University of Crete, Vassilika Vouton, 71003 Heraklion, Crete, Greece
| | - Max R. McGillen
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
| | - Shona C. Smith
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
| | - Aaron M. Jubb
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, 80309 United States
| | - Robert W. Portmann
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
| | - Bradley D. Hall
- Earth
System Research Laboratory, Global Monitoring Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
| | - Eric L. Fleming
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 United States
- Science Systems and Applications, Inc., Lanham, Maryland, 20706 United States
| | - Charles H. Jackman
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771 United States
| | - James B. Burkholder
- Earth
System Research Laboratory, Chemical Sciences Division, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, Colorado, 80305 United States
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25
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Zádor J, Huang H, Welz O, Zetterberg J, Osborn DL, Taatjes CA. Directly measuring reaction kinetics of ˙QOOH – a crucial but elusive intermediate in hydrocarbon autoignition. Phys Chem Chem Phys 2013; 15:10753-60. [DOI: 10.1039/c3cp51185e] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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