1
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High-pressure limit rate rules for intramolecular H-migration reactions of α,β-hydroxyalkylperoxy radicals. Theor Chem Acc 2021. [DOI: 10.1007/s00214-021-02849-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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2
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Rösch D, Caravan RL, Taatjes CA, Au K, Almeida R, Osborn DL. Absolute Photoionization Cross Section of the Simplest Enol, Vinyl Alcohol. J Phys Chem A 2021; 125:7920-7928. [PMID: 34468152 DOI: 10.1021/acs.jpca.1c05825] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The absolute photoionization cross section of vinyl alcohol was determined by multiplexed photoionization mass spectrometry of the Norrish type II photodissociation of butanal at 308 nm. The measured cross sections at 10.005 and 10.205 eV are 7.5 ± 1.9 and 8.1 ± 1.9 MB, respectively. A higher signal-to-noise ratio photoionization spectrum of vinyl alcohol was recorded via the pyrolysis of 2-chloroethanol and scaled to the absolute cross sections measured using the Norrish type II method. From a comparison of our spectrum with previously reported photoelectron spectra we conclude that vinyl alcohol is mainly ionized by direct ionization in the energy range of 9-9.6 eV, whereas autoionization is responsible for the steady rise in the photoionization spectrum above the end of the Franck-Condon envelope at 9.9 eV.
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Affiliation(s)
- Daniel Rösch
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States
| | - Rebecca L Caravan
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Craig A Taatjes
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States
| | - Kendrew Au
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551-0969, United States
| | - Raybel Almeida
- 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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3
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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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4
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Li Y, Zhao Q, Zhang Y, Huang Z, Sarathy SM. A Systematic Theoretical Kinetics Analysis for the Waddington Mechanism in the Low-Temperature Oxidation of Butene and Butanol Isomers. J Phys Chem A 2020; 124:5646-5656. [PMID: 32574048 PMCID: PMC7467721 DOI: 10.1021/acs.jpca.0c03515] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
The
Waddington mechanism, or the Waddington-type reaction pathway,
is crucial for low-temperature oxidation of both alkenes and alcohols.
In this study, the Waddington mechanism in the oxidation chemistry
of butene and butanol isomers was systematically investigated. Fundamental
quantum chemical calculations were conducted for the rate constants
and thermodynamic properties of the reactions and species in this
mechanism. Calculations were performed using two different ab initio solvers: Gaussian 09 and Orca 4.0.0, and two different
kinetic solvers: PAPR and MultiWell, comprehensively. Temperature-
and pressure-dependent rate constants were performed based on the
transition state theory, associated with the Rice Ramsperger Kassel
Marcus and master equation theories. Temperature-dependent thermochemistry
(enthalpies of formation, entropy, and heat capacity) of all major
species was also conducted, based on the statistical thermodynamics.
Of the two types of reaction, dissociation reactions were significantly
faster than isomerization reactions, while the rate constants of both
reactions converged toward higher temperatures. In comparison, between
two ab initio solvers, the barrier height difference
among all isomerization and dissociation reactions was about 2 and
0.5 kcal/mol, respectively, resulting in less than 50%, and a factor
of 2–10 differences for the predicted rate coefficients of
the two reaction types, respectively. Comparing the two kinetic solvers,
the rate constants of the isomerization reactions showed less than
a 32% difference, while the rate of one dissociation reaction (P1
↔ WDT12) exhibited 1–2 orders of magnitude discrepancy.
Compared with results from the literature, both reaction rate coefficients
(R4 and R5 reaction systems) and species’ thermochemistry (all
closed shell molecules and open shell radicals R4 and R5) showed good
agreement with the corresponding values obtained from the literature.
All calculated results can be directly used for the chemical kinetic
model development of butene and butanol isomer oxidation.
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Affiliation(s)
- Yang Li
- King Abdullah University of Science and Technology, Clean Combustion Research Centre, Thuwal 23955, Saudi Arabia
| | - Qian Zhao
- State Key Laboratory of Multiphase Flows in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Yingjia Zhang
- State Key Laboratory of Multiphase Flows in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Zuohua Huang
- State Key Laboratory of Multiphase Flows in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - S Mani Sarathy
- King Abdullah University of Science and Technology, Clean Combustion Research Centre, Thuwal 23955, Saudi Arabia
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5
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Antonov I, Voronova K, Chen MW, Sztáray B, Hemberger P, Bodi A, Osborn DL, Sheps L. To Boldly Look Where No One Has Looked Before: Identifying the Primary Photoproducts of Acetylacetone. J Phys Chem A 2019; 123:5472-5490. [DOI: 10.1021/acs.jpca.9b04640] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Ivan Antonov
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Krisztina Voronova
- Department of Chemistry, University of the Pacific, Stockton, California 95211, United States
| | - Ming-Wei Chen
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Bálint Sztáray
- Department of Chemistry, University of the Pacific, Stockton, California 95211, United States
| | | | - Andras Bodi
- Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - 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
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6
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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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7
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Prendergast MB, Kirk BB, Savee JD, Osborn DL, Taatjes CA, Hemberger P, Blanksby SJ, da Silva G, Trevitt AJ. Product detection study of the gas-phase oxidation of methylphenyl radicals using synchrotron photoionisation mass spectrometry. Phys Chem Chem Phys 2019; 21:17939-17949. [DOI: 10.1039/c9cp01935a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reactions of ortho and meta-methylphenyl radicals with oxygen form products that depend acutely on the position of the methyl group.
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Affiliation(s)
| | | | - John D. Savee
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - David L. Osborn
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - Craig A. Taatjes
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - Patrick Hemberger
- Laboratory for Femtochemistry and Synchrotron Radiation
- Paul Scherrer Institut
- CH-5232 Villigen PSI
- Switzerland
| | - Stephen J. Blanksby
- Central Analytical Research Facility
- Queensland University of Technology
- Brisbane QLD 4001
- Australia
| | - Gabriel da Silva
- Department of Chemical Engineering
- The University of Melbourne
- Melbourne
- Australia
| | - Adam J. Trevitt
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
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8
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Lei X, Chen D, Wang W, Liu F, Wang W. Quantum chemical studies of the OH-initiated oxidation reactions of propenols in the presence of O2. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1537527] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Xiaoyang Lei
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Dongping Chen
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Weina Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Fengyi Liu
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Wenliang Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
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9
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Sheps L, Rotavera B, Eskola AJ, Osborn DL, Taatjes CA, Au K, Shallcross DE, Khan MAH, Percival CJ. The reaction of Criegee intermediate CH 2OO with water dimer: primary products and atmospheric impact. Phys Chem Chem Phys 2018; 19:21970-21979. [PMID: 28805226 DOI: 10.1039/c7cp03265j] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rapid reaction of the smallest Criegee intermediate, CH2OO, with water dimers is the dominant removal mechanism for CH2OO in the Earth's atmosphere, but its products are not well understood. This reaction was recently suggested as a significant source of the most abundant tropospheric organic acid, formic acid (HCOOH), which is consistently underpredicted by atmospheric models. However, using time-resolved measurements of reaction kinetics by UV absorption and product analysis by photoionization mass spectrometry, we show that the primary products of this reaction are formaldehyde and hydroxymethyl hydroperoxide (HMHP), with direct HCOOH yields of less than 10%. Incorporating our results into a global chemistry-transport model further reduces HCOOH levels by 10-90%, relative to previous modeling assumptions, which indicates that the reaction CH2OO + water dimer by itself cannot resolve the discrepancy between the measured and predicted HCOOH levels.
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Affiliation(s)
- Leonid Sheps
- Combustion Research Facility, Sandia National Laboratories, 7011 East Ave., MS 9055, Livermore, California 94551, USA.
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10
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Bu L, Ciesielski PN, Robichaud DJ, Kim S, McCormick RL, Foust TD, Nimlos MR. Understanding Trends in Autoignition of Biofuels: Homologous Series of Oxygenated C5 Molecules. J Phys Chem A 2017; 121:5475-5486. [PMID: 28678503 DOI: 10.1021/acs.jpca.7b04000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lintao Bu
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Peter N. Ciesielski
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - David J. Robichaud
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Seonah Kim
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Robert L. McCormick
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Thomas D. Foust
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mark R. Nimlos
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
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11
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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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12
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Prendergast MB, Kirk BB, Savee JD, Osborn DL, Taatjes CA, Masters KS, Blanksby SJ, da Silva G, Trevitt AJ. Formation and stability of gas-phase o-benzoquinone from oxidation of ortho-hydroxyphenyl: a combined neutral and distonic radical study. Phys Chem Chem Phys 2016; 18:4320-32. [DOI: 10.1039/c5cp02953h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The o-hydroxyphenyl radical reacts with O2 to form o-benzoquinone + OH and cyclopentadienone is assigned as a secondary product.
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Affiliation(s)
| | | | - John D. Savee
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - David L. Osborn
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - Craig A. Taatjes
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - Kye-Simeon Masters
- School of Chemistry, Physics and Mechanical Engineering
- Faculty of Science and Engineering
- Queensland University of Technology
- Brisbane
- Australia
| | - Stephen J. Blanksby
- Central Analytical Research Facility
- Queensland University of Technology
- Brisbane
- Australia
| | - Gabriel da Silva
- Department of Chemical and Biomolecular Engineering
- The University of Melbourne
- Melbourne
- Australia
| | - Adam J. Trevitt
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
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13
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Gozem S, Gunina AO, Ichino T, Osborn DL, Stanton JF, Krylov AI. Photoelectron wave function in photoionization: plane wave or Coulomb wave? J Phys Chem Lett 2015; 6:4532-4540. [PMID: 26509428 DOI: 10.1021/acs.jpclett.5b01891] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The calculation of absolute total cross sections requires accurate wave functions of the photoelectron and of the initial and final states of the system. The essential information contained in the latter two can be condensed into a Dyson orbital. We employ correlated Dyson orbitals and test approximate treatments of the photoelectron wave function, that is, plane and Coulomb waves, by comparing computed and experimental photoionization and photodetachment spectra. We find that in anions, a plane wave treatment of the photoelectron provides a good description of photodetachment spectra. For photoionization of neutral atoms or molecules with one heavy atom, the photoelectron wave function must be treated as a Coulomb wave to account for the interaction of the photoelectron with the +1 charge of the ionized core. For larger molecules, the best agreement with experiment is often achieved by using a Coulomb wave with a partial (effective) charge smaller than unity. This likely derives from the fact that the effective charge at the centroid of the Dyson orbital, which serves as the origin of the spherical wave expansion, is smaller than the total charge of a polyatomic cation. The results suggest that accurate molecular photoionization cross sections can be computed with a modified central potential model that accounts for the nonspherical charge distribution of the core by adjusting the charge in the center of the expansion.
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Affiliation(s)
- Samer Gozem
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Anastasia O Gunina
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Takatoshi Ichino
- Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories , Livermore, California 94551, United States
| | - John F Stanton
- Institute for Theoretical Chemistry, Department of Chemistry, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Anna I Krylov
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
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14
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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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15
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Antonov IO, Kwok J, Zádor J, Sheps L. A Combined Experimental and Theoretical Study of the Reaction OH + 2-Butene in the 400–800 K Temperature Range. J Phys Chem A 2015; 119:7742-52. [DOI: 10.1021/acs.jpca.5b01012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ivan O. Antonov
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
| | - Justin Kwok
- 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
| | - Leonid Sheps
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551-0969, United States
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16
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Zhang W, Du B. Theoretical Investigation on the Reaction between OH Radical and 4,4-Dimethyl-1-pentene in the Presence of O2. J Phys Chem A 2015; 119:4065-72. [PMID: 25849042 DOI: 10.1021/acs.jpca.5b02274] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The atmospheric oxidation mechanism of 4,4-dimethyl-1-pentene (DMP441) initiated by OH radical has been theoretically investigated at the BH&HLYP/6-311++G(d,p) and CCSD(T)/6-31+G(d,p) levels of theory. HC(O)H and 3,3-dimethylbutanal [(CH3)3CCH2C(O)H] are identified in our calculations as major products in the OH-radical-initiated degradation of DMP441 in the presence of O2. However, the epoxide conformers and enols are expected to be minor products because of the high isomerization barriers involved. The calculated results are in qualitative accordance with experimental evidence. Conventional transition state theory has been used to calculate the rate constants of the initial addition channels of the OH + DMP441 reaction over the temperature range 220-500 K. The computed total rate constant at 298 K is 2.20 × 10(-11) cm(3) molecule(-1) s(-1), which is in very good agreement with the experimental value. Furthermore, it has been found that the calculated rate constant exhibits a weak non-Arrhenius behavior over the temperature range 220-500 K. The computed expression for the rate constant is k(OH+DMP441) = 1.22 × 10(-12) exp[(880 K)/T] cm(3) molecule(-1) s(-1).
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Affiliation(s)
- Weichao Zhang
- College of Chemistry and Chemical Engineering and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, People's Republic of China
| | - Benni Du
- College of Chemistry and Chemical Engineering and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, People's Republic of China
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Karwat DMA, Wooldridge MS, Klippenstein SJ, Davis MJ. Effects of new Ab initio rate coefficients on predictions of species formed during n-butanol ignition and pyrolysis. J Phys Chem A 2015; 119:543-51. [PMID: 25560388 DOI: 10.1021/jp509279d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Experimental, time-resolved species profiles provide critical tests in developing accurate combustion models for biofuels such as n-butanol. A number of such species profiles measured by Karwat et al. [ Karwat, D. M. A.; et al. J. Phys. Chem. A 2011 , 115 , 4909 ] were discordant with predictions from a well-tested chemical kinetic mechanism developed by Black et al. [ Black, G.; et al. Combust. Flame 2010 , 157 , 363 ]. Since then, significant theoretical and experimental efforts have focused on determining the rate coefficients of primary n-butanol consumption pathways in combustion environments, including H atom abstraction reactions from n-butanol by key radicals such as HO2 and OH, as well as the decomposition of the radicals formed by these H atom abstractions. These reactions not only determine the overall reactivity of n-butanol, but also significantly affect the concentrations of intermediate species formed during n-butanol ignition. In this paper we explore the effect of incorporating new ab initio predictions into the Black et al. mechanism on predictions of ignition delay time and species time histories for the experimental conditions studied by Karwat et al. The revised predictions for the intermediate species time histories are in much improved agreement with the measurements, but some discrepancies persist. A rate of production analysis comparing the effects of various modifications to the Black et al. mechanism shows significant changes in the predicted consumption pathways of n-butanol, and of the hydroxybutyl and butoxy radicals formed by H atom abstraction from n-butanol. The predictions from the newly revised mechanism are in very good agreement with the low-pressure n-butanol pyrolysis product species measurements of Stranic et al. [ Stranic, I.; et al. Combust. Flame 2012 , 159 , 3242 ] for all but one species. Importantly, the changes to the Black et al. mechanism show that concentrations of small products from n-butanol pyrolysis are sensitive to different reactions than those presented by Stranic et al.
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Affiliation(s)
- Darshan M A Karwat
- Department of Mechanical Engineering and ‡Department of Aerospace Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States
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