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Yang M, Wang J. Comprehensive Multipath Variational Kinetics Study on Hydrogen Abstraction Reactions from Three Typical Dimethylcyclohexane Isomers by Hydroxyl Radicals: from the Electronic Structure to Model Applications. J Phys Chem A 2024; 128:4517-4531. [PMID: 38804972 DOI: 10.1021/acs.jpca.4c00480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Cycloalkanes serve as an important class of chemical components in both fossil and alternative transportation fuels and have attracted considerable attention from the combustion community. Hydrogen abstractions from cycloalkanes by hydroxyl radicals initiate the fuel decomposition process and trigger off the subsequent chain reactions and thus play an important role in both combustion and atmospheric chemistry. The target of this study is to fill the vacancy in kinetics data toward the H-abstraction reactions by hydroxyl radical from three typical dimethylcyclohexane isomers through first-principles and direct dynamics. The rate constants involving 18 elementary reactions in total were accurately determined by the multipath canonical variational transition state theory with the multidimensional small-curvature correction for tunneling (MP-CVT/SCT), over a broad temperature range of 200-2000 K. The significant roles of multistructural torsional anharmonicity and recrossing effects were stressed per abstraction site, while the quantum tunneling effect was found to be slight at temperatures of interest in combustion. The discrepancies observed among different reaction systems at a similar abstraction site highlight the fuel molecular effects on site-specific rate constants. The comparison results of total rate constants given by different dynamics approaches prove the importance of considering the torsional anharmonicity, recrossing, and tunneling effects, and the robust feature of the simplified MS-CVT/SCT. The calculated total constants for dimethylcyclohexane isomers by OH are consistent with those measured for methylcyclohexane and 1,4-dimethylcyclohexane at low temperatures. The branching ratio analysis confirms the predominant role of the tertiary abstraction at low-to-intermediate temperatures and its growing competition with distinct secondary abstractions as temperature increases. The calculated rate constants were eventually fitted into the analytical expressions and incorporated into the kinetic models to learn about the influences on modeling performance.
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Affiliation(s)
- Mo Yang
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing 100191, PR China
| | - Juan Wang
- National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics, School of Energy and Power Engineering, Beihang University, Beijing 100191, PR China
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2
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Tokuhashi K, Takizawa K, Kondo S. Reaction Rates of OH Radicals with CH 3OCF 2CHFCF 3 and CHF 2CF 2OCH 2CF 2CHF 2: Measurements and Estimation Using Neural Network Method. J Phys Chem A 2024; 128:1134-1141. [PMID: 38305227 DOI: 10.1021/acs.jpca.3c07376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
The reaction rates of OH radicals with CH3OCF2CHFCF3 (k1) and CHF2CF2OCH2CF2CHF2 (k2) were measured over a temperature range of 250-430 K. Kinetic measurements were performed using the flash and laser photolysis methods combined with a laser-induced fluorescence technique. The Arrhenius rate parameters were determined as k1 = (2.52 ± 0.25) × 10-12·exp[-(1390 ± 30)/T], k2 = (1.83 ± 0.20) × 10-12·exp[-(1420 ± 35)/T] cm3 molecule-1 s-1. The infrared absorption spectra of the two hydrofluoroethers were measured at approximately 298 K in 760 Torr of N2. The atmospheric lifetimes of CH3OCF2CHFCF3 and CHF2CF2OCH2CF2CHF2 have been estimated as 2.5 and 3.8 years, respectively, and their global warming potentials were determined as 245 and 405, respectively. Additionally, a method, using a three-layered feed-forward neural network, for estimating the rates of the reaction of the OH radicals with alkanes, ethers, and alcohols was investigated. The ratios of the calculated reaction rates to the observed ones agreed within a factor of 2. The ability of the neural network method to predict reaction rates was examined by using a leave-one-out test.
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Affiliation(s)
- Kazuaki Tokuhashi
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Kenji Takizawa
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Shigeo Kondo
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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3
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Meena KK, Sorty AM, Bitla U, Shinde AL, Kumar S, Wakchaure GC, Kumar S, Kanwat M, Singh DP. Stress-responsive gene regulation conferring salinity tolerance in wheat inoculated with ACC deaminase producing facultative methylotrophic actinobacterium. FRONTIERS IN PLANT SCIENCE 2023; 14:1249600. [PMID: 37780501 PMCID: PMC10534068 DOI: 10.3389/fpls.2023.1249600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/21/2023] [Indexed: 10/03/2023]
Abstract
Microbes enhance crop resilience to abiotic stresses, aiding agricultural sustainability amid rising global land salinity. While microbes have proven effective via seed priming, soil amendments, and foliar sprays in diverse crops, their mechanisms remain less explored. This study explores the utilization of ACC deaminase-producing Nocardioides sp. to enhance wheat growth in saline environments and the molecular mechanisms underlying Nocardioides sp.-mediated salinity tolerance in wheat. The Nocardioides sp. inoculated seeds were grown under four salinity regimes viz., 0 dS m-1, 5 dS m-1, 10 dS m-1, and 15 dS m-1, and vegetative growth parameters including shoot-root length, germination percentage, seedling vigor index, total biomass, and shoot-root ratio were recorded. The Nocardioides inoculated wheat plants performed well under saline conditions compared to uninoculated plants and exhibited lower shoot:root (S:R) ratio (1.52 ± 0.14 for treated plants against 1.84 ± 0.08 for untreated plants) at salinity level of 15 dS m-1 and also showed improved biomass at 5 dS m-1 and 10 dS m-1. Furthermore, the inoculated plants also exhibited higher protein content viz., 22.13 mg g-1, 22.10 mg g-1, 22.63 mg g-1, and 23.62 mg g-1 fresh weight, respectively, at 0 dS m-1, 5 dS m-1, 10 dS m-1, and 15 dS m-1. The mechanisms were studied in terms of catalase, peroxidase, superoxide dismutase, and ascorbate peroxidase activity, free radical scavenging potential, in-situ localization of H2O2 and superoxide ions, and DNA damage. The inoculated seedlings maintained higher enzymatic and non-enzymatic antioxidant potential, which corroborated with reduced H2O2 and superoxide localization within the tissue. The gene expression profiles of 18 stress-related genes involving abscisic acid signaling, salt overly sensitive (SOS response), ion transporters, stress-related transcription factors, and antioxidant enzymes were also analyzed. Higher levels of stress-responsive gene transcripts, for instance, TaABARE (~+7- and +10-fold at 10 dS m-1 and 15 dS m-1); TaHAk1 and hkt1 (~+4- and +8-fold at 15 dS m-1); antioxidant enzymes CAT, MnSOD, POD, APX, GPX, and GR (~+4, +3, +5, +4, +9, and +8 folds and), indicated actively elevated combat mechanisms in inoculated seedlings. Our findings emphasize Nocardioides sp.-mediated wheat salinity tolerance via ABA-dependent cascade and salt-responsive ion transport system. This urges additional study of methylotrophic microbes to enhance crop abiotic stress resilience.
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Affiliation(s)
- Kamlesh K. Meena
- Division of Integrated Farming System, Indian Council of Agricultural Research (ICAR)-Central Arid Zone Research Institute, Jodhpur, India
| | - Ajay M. Sorty
- School of Soil Stress Management, Indian Council of Agricultural Research (ICAR)-National Institute of Abiotic Stress Management, Baramati, India
- Department of Environmental Science–Environmental Microbiology, Aarhus University, Roskilde, Denmark
| | - Utkarsh Bitla
- School of Soil Stress Management, Indian Council of Agricultural Research (ICAR)-National Institute of Abiotic Stress Management, Baramati, India
| | - Akash L. Shinde
- School of Soil Stress Management, Indian Council of Agricultural Research (ICAR)-National Institute of Abiotic Stress Management, Baramati, India
| | - Satish Kumar
- School of Soil Stress Management, Indian Council of Agricultural Research (ICAR)-National Institute of Abiotic Stress Management, Baramati, India
- Department of Biochemistry, Indian Council of Agricultural Research (ICAR)-Directorate of Onion and Garlic Research, Pune, India
| | - Goraksha C. Wakchaure
- School of Soil Stress Management, Indian Council of Agricultural Research (ICAR)-National Institute of Abiotic Stress Management, Baramati, India
| | - Shrvan Kumar
- Division of Integrated Farming System, Indian Council of Agricultural Research (ICAR)-Central Arid Zone Research Institute, Jodhpur, India
| | - Manish Kanwat
- Division of Integrated Farming System, Indian Council of Agricultural Research (ICAR)-Central Arid Zone Research Institute, Jodhpur, India
| | - Dhananjaya P. Singh
- Indian Council of Agricultural Research (ICAR)-Crop Improvement Division, Indian Institute of Vegetable Research, Varanasi, India
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4
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Orkin VL, Khamaganov VG, Kurylo MJ. Experimental kinetic study of the reactions between OH radicals and three 2‐butenes over the temperature range 220–370 K and pressure range 0.67–40 kPa (5–300 Torr). INT J CHEM KINET 2023. [DOI: 10.1002/kin.21630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Vladimir L. Orkin
- National Institute of Standards and Technology Gaithersburg Maryland USA
| | | | - Michael J. Kurylo
- Goddard Earth Sciences, Technology, and Research (GESTAR) Universities Space Research Association Greenbelt Maryland USA
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5
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Arsene C, Bejan IG, Roman C, Olariu RI, Minella M, Passananti M, Carena L, Vione D. Evaluation of the Environmental Fate of a Semivolatile Transformation Product of Ibuprofen Based on a Simple Two-Media Fate Model. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15650-15660. [PMID: 36240489 PMCID: PMC9670848 DOI: 10.1021/acs.est.2c04867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Partitioning between surface waters and the atmosphere is an important process, influencing the fate and transport of semi-volatile contaminants. In this work, a simple methodology that combines experimental data and modeling was used to investigate the degradation of a semi-volatile pollutant in a two-phase system (surface water + atmosphere). 4-Isobutylacetophenone (IBAP) was chosen as a model contaminant; IBAP is a toxic transformation product of the non-steroidal, anti-inflammatory drug ibuprofen. Here, we show that the atmospheric behavior of IBAP would mainly be characterized by reaction with •OH radicals, while degradation initiated by •NO3 or direct photolysis would be negligible. The present study underlines that the gas-phase reactivity of IBAP with •OH is faster, compared to the likely kinetics of volatilization from aqueous systems. Therefore, it might prove very difficult to detect gas-phase IBAP. Nevertheless, up to 60% of IBAP occurring in a deep and dissolved organic carbon-rich water body might be eliminated via volatilization and subsequent reaction with gas-phase •OH. The present study suggests that the gas-phase chemistry of semi-volatile organic compounds which, like IBAP, initially occur in natural water bodies in contact with the atmosphere is potentially very important in some environmental conditions.
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Affiliation(s)
- Cecilia Arsene
- Department
of Chemistry, Faculty of Chemistry, “Alexandru
Ioan Cuza” University of Iasi, 11 Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(CERNESIM), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(RECENT AIR), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
| | - Iustinian G. Bejan
- Department
of Chemistry, Faculty of Chemistry, “Alexandru
Ioan Cuza” University of Iasi, 11 Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(CERNESIM), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(RECENT AIR), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
| | - Claudiu Roman
- Department
of Chemistry, Faculty of Chemistry, “Alexandru
Ioan Cuza” University of Iasi, 11 Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(CERNESIM), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(RECENT AIR), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
| | - Romeo I. Olariu
- Department
of Chemistry, Faculty of Chemistry, “Alexandru
Ioan Cuza” University of Iasi, 11 Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(CERNESIM), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
- Integrated
Centre of Environmental Science Studies in the North Eastern Region
(RECENT AIR), “Alexandru Ioan Cuza”
University of Iasi, 11
Carol I, 700506Iasi, Romania
| | - Marco Minella
- Dipartimento
di Chimica, Università degli Studi
di Torino, Via Pietro Giuria 5, 10125Torino, Italy
| | - Monica Passananti
- Dipartimento
di Chimica, Università degli Studi
di Torino, Via Pietro Giuria 5, 10125Torino, Italy
- Institute
for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, FI-00014Helsinki, Finland
| | - Luca Carena
- Dipartimento
di Chimica, Università degli Studi
di Torino, Via Pietro Giuria 5, 10125Torino, Italy
| | - Davide Vione
- Dipartimento
di Chimica, Università degli Studi
di Torino, Via Pietro Giuria 5, 10125Torino, Italy
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Wu J, Ning H, Ren W. A CGA-ONIOM-DFT framework for accurate and efficient determination of thermodynamics and Kinetics: Case study of cyclopentane reaction with hydroxyl radical. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Aguirre F, Lobos MLN, Basto MAL, Teruel MA, Moyano EL, Blanco MB. Volatile Organic Compounds Released During the Fast Pyrolysis of Peanut Shells and Environmental Implications. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2022; 108:1139-1146. [PMID: 35303142 DOI: 10.1007/s00128-022-03481-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
The biomass conversion technologies, especially different types of pyrolysis, have been intensively studied to improve biomass energy transformation suggesting a low impact on the environment. In particular, fast pyrolysis of biomass is considered to be a thermal process in which the starting material is converted to bio-oil, char and gas products. In this work, volatile organic compounds (VOCs) of the gaseous fraction of peanut shells fast pyrolysis were collected and identified at atmospheric pressure. Aromatic compounds, hydrocarbons, furans and other oxygenated compounds were identified using solid phase microextraction (SPME) and gas chromatography coupled to mass spectrometry (CG-MS) as a detection system. The composition of volatiles was analyzed and compared with the constituents of liquid fraction for comparative purposes. Atmospheric implications of the main compounds identified in the gases fraction were assessed by determining tropospheric lifetimes of the VOCs identified and its impact on environment at the local, regional or global scale.
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Affiliation(s)
- Fabricio Aguirre
- Departamento de Fisicoquímica, LUQCA, INFIQC-CCT Córdoba, Facultad Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina
| | - María L Nieva Lobos
- Departamento de Química Orgánica, INFIQC-CCT Córdoba, Facultad Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina
| | - María A López Basto
- Departamento de Fisicoquímica, LUQCA, INFIQC-CCT Córdoba, Facultad Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina
| | - Mariano A Teruel
- Departamento de Fisicoquímica, LUQCA, INFIQC-CCT Córdoba, Facultad Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina
| | - Elizabeth L Moyano
- Departamento de Química Orgánica, INFIQC-CCT Córdoba, Facultad Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina.
| | - María B Blanco
- Departamento de Fisicoquímica, LUQCA, INFIQC-CCT Córdoba, Facultad Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina.
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8
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Chen W, Guo X, Chen L, Zhang R, Li Y, Feng H, Xu X, Zhang X. A kinetics study on hydrogen abstraction reactions of cyclopentane by hydrogen, methyl, and ethyl radicals. Phys Chem Chem Phys 2021; 23:7333-7342. [PMID: 33876093 DOI: 10.1039/d1cp00386k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrogen abstraction reactions of (cyclo)alkanes by radicals play a fundamental role in both combustion and atmospheric chemistry. In this work, we select three common radicals in the pyrolysis of hydrocarbon fuels: hydrogen radical (H[combining dot above]), methyl radical (ĊH3), and ethyl radical (ĊH2CH3) to investigate the kinetics of their hydrogen abstraction reactions with cyclopentane. The rate constants over a broad temperature range of 150-3000 K are calculated by using the multi-structural variational transition state theory in the small-curvature tunneling approximation (MS-CVT/SCT), by which the multi-structural torsional (MS-T) anharmonicity of partition functions, variational effects, and corner-cutting tunneling are all included in dynamics calculations. We stress the particular importance of considering the MS-T anharmonicity in the rate constant calculation for the reaction with the ethyl radical compared to those with hydrogen and methyl radicals. The MS-T anharmonicity significantly accelerates the reaction with the ethyl radical in the whole temperature range, and in particular, it increases the rate constant by a factor of >-9 at 1000 K. We also found that the tunneling effect drastically increases the rate constants at low-temperatures by up to 3-5 orders of magnitudes. The calculated reaction rate constants have an order of .
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Affiliation(s)
- Wenqi Chen
- Center for Combustion Energy, Department of Energy and Power Engineering, and Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China.
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9
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Characterization of Total OH Reactivity in a Rapeseed Field: Results from the COV3ER Experiment in April 2017. ATMOSPHERE 2020. [DOI: 10.3390/atmos11030261] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Croplands remain poorly studied ecosystems in terms of total hydroxyl radical (OH) reactivity, especially when compared to forests. As part of the COV3ER project, total OH reactivity (ROH), defined as the total loss rate of OH due to its reaction with reactive species in the atmosphere, was characterized in a rapeseed field (Grignon, France) during the blooming season in April 2017. Measurements were performed in a dynamic chamber as well as in ambient air using the Comparative Reactivity Method (CRM). Complementary measurements of organic (including a proton transfer reaction quadrupole ion–time of flight mass spectrometry, PTRQi-ToFMS) and inorganic compounds were also performed in order to calculate the expected OH reactivity and evaluate the missing fraction. Measured ROH varied diurnally in the dynamic chamber (mROHchamber) with maxima around 20 to 30 s−1 at midday and minima during dark hours, following the variability of the enclosed branch VOCsrapeseed, which is light- and temperature-dependent. Oxygenated VOCs were the major compounds emitted by the rapeseed crop. However, in terms of contribution to OH reactivity, isoprene accounted for 40% during the daytime, followed by acetaldehyde (21%) and monoterpenes (18%). The comparison between mROHchamber and calculated ROH (cROHchamber) exhibited little or no difference during dark hours, whereas a maximum difference appeared around midday, highlighting a significant missing fraction (46% on average during daytime) mainly related to biogenic temperature- and/or light-dependent emissions.
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10
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Wu J, Gao LG, Ren W, Truhlar DG. Anharmonic kinetics of the cyclopentane reaction with hydroxyl radical. Chem Sci 2020; 11:2511-2523. [PMID: 34084417 PMCID: PMC8157450 DOI: 10.1039/c9sc05632g] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/14/2020] [Indexed: 12/02/2022] Open
Abstract
Cyclopentane is one of the major constituents of transportation fuels, especially jet fuel and diesel, and also is a volatile organic compound with a significant presence in the atmosphere. Hydrogen abstraction from cyclopentane by hydroxyl radical plays a significant role in combustion and atmospheric chemistry. In this work we study the kinetics of this reaction at 200-2000 K using direct dynamics calculations in which the potential energy surface is obtained by quantum mechanical electronic structure calculations. The forward and reverse barrier heights and reaction energies obtained by the CCSD(T)-F12a/jun-cc-pVTZ coupled cluster calculations are used as a benchmark to select an accurate electronic structure method among 36 combinations of exchange-correlation functional and basis set. The selected M06-2X/MG3S method shows the best performance with a mean unsigned deviation from the benchmark of only 0.22 kcal mol-1 for reaction energies and barrier heights. A quadratic-quartic function is adopted to describe the ring bending potential of cyclopentane, and the quartic anharmonicity in the bending mode is treated by a one-dimensional Schrödinger equation using both Wentzel-Kramers-Brillouin (WKB) and Fourier Grid Hamiltonian (FGH) methods. The torsional anharmonicity in the transition state is treated in turn by the free rotor approximation, the one-dimensional hindered rotor approximation, and the multi-structural torsional anharmonicity method. Rate constants of the title reaction are computed by canonical variational transition state theory including tunneling by the multi-dimensional small-curvature tunneling approximation (CVT/SCT). The final rate constants include the quasiharmonic, quadratic-quartic, and torsional anharmonicity. Our calculations are in excellent agreement with all the experimental data available at both combustion and atmospheric temperatures with a deviation of less than 30%.
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Affiliation(s)
- Junjun Wu
- Department of Mechanical and Automation Engineering, Shenzhen Research Institute, The Chinese University of Hong Kong New Territories Hong Kong SAR China
- Department of Chemistry, Chemical Theory Center and Supercomputing Institute, University of Minnesota Minneapolis USA
| | - Lu Gem Gao
- Department of Chemistry, Chemical Theory Center and Supercomputing Institute, University of Minnesota Minneapolis USA
- Center for Combustion Energy, Department of Energy and Power Engineering, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Tsinghua University Beijing China
| | - Wei Ren
- Department of Mechanical and Automation Engineering, Shenzhen Research Institute, The Chinese University of Hong Kong New Territories Hong Kong SAR China
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center and Supercomputing Institute, University of Minnesota Minneapolis USA
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11
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Sharma K, Kalita S, Sarma NS, Devi A. Treatment of crude oil contaminated wastewater via an electrochemical reaction. RSC Adv 2020; 10:1925-1936. [PMID: 35494585 PMCID: PMC9047067 DOI: 10.1039/c9ra09202a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 12/23/2019] [Indexed: 12/23/2022] Open
Abstract
A cost-effective and catalyst-free approach for the treatment of oil field formation water has been extensively explored in this work. ZnO NPs were synthesized via an electrochemical reaction using hydrogen peroxide as the electrolyte. The XRD and TEM analysis depicted the high purity and wurtzite hexagonal structure of ZnO NPs with an average size of 35 ± 5 nm. TGA data showed the thermal stability of the synthesized material up to 750 °C. The efficiency of the removal of hydrocarbons from formation water by the combination of electrochemical reaction and synthesized ZnO NPs was monitored by GC-MS and FTIR. GC-MS analysis revealed that out of 214 compounds (present in the untreated sample), a total of 131 compounds were adsorbed by ZnO NPs. Further, the absence of any compound in the chromatogram of the treated sample attests that the rest of the compounds were completely or partially degraded by electrochemical degradation reaction. Moreover, this technique overcomes some of the important drawbacks of the existing techniques in the area of electrochemical research, such as the generation of toxic byproducts, unwanted side reactions, and involvement of hazardous chemicals. A novel electrochemical reaction was developed for the treatment of formation water and subsequently ZnO nanoparticles were synthesised in the in situ condition and further used as an adsorbing material for petroleum hydrocarbons.![]()
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Affiliation(s)
- Khanindra Sharma
- Environmental Chemistry Laboratory
- Resource Management and Environment Section
- Life Sciences Division
- Institute of Advanced Study in Science and Technology
- Guwahati 781035
| | - Suravi Kalita
- Environmental Chemistry Laboratory
- Resource Management and Environment Section
- Life Sciences Division
- Institute of Advanced Study in Science and Technology
- Guwahati 781035
| | - Neelotpal Sen Sarma
- Advanced Materials Laboratory
- Physical Sciences Division
- Institute of Advanced Study in Science and Technology
- Guwahati 781035
- India
| | - Arundhuti Devi
- Environmental Chemistry Laboratory
- Resource Management and Environment Section
- Life Sciences Division
- Institute of Advanced Study in Science and Technology
- Guwahati 781035
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12
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Ma Z, Liu C, Zhang C, Liu P, Ye C, Xue C, Zhao D, Sun J, Du Y, Chai F, Mu Y. The levels, sources and reactivity of volatile organic compounds in a typical urban area of Northeast China. J Environ Sci (China) 2019; 79:121-134. [PMID: 30784438 DOI: 10.1016/j.jes.2018.11.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 05/22/2023]
Abstract
Air concentrations of volatile organic compounds (VOCs) were continually measured at a monitoring site in Shenyang from 20 August to 16 September 2017. The average concentrations of alkanes, alkenes, aromatics and carbonyls were 28.54, 6.30, 5.59 and 9.78 ppbv, respectively. Seven sources were identified by the Positive Matrix Factorization model based on the measurement data of VOCs and CO. Vehicle exhaust contributed the most (36.15%) to the total propene-equivalent concentration of the measured VOCs, followed by combustion emission (16.92%), vegetation emission and secondary formation (14.33%), solvent usage (10.59%), petrochemical industry emission (9.89%), petrol evaporation (6.28%), and liquefied petroleum gas (LPG) usage (5.84%). Vehicle exhaust, solvent usage and combustion emission were found to be the top three VOC sources for O3 formation potential, accounting for 34.52%, 16.55% and 11.94%, respectively. The diurnal variation of the total VOCs from each source could be well explained by their emission characteristics, e.g., the two peaks of VOC concentrations from LPG usage were in line with the cooking times for breakfast and lunch. Wind rose plots of the VOCs from each source could reveal the possible distribution of the sources around the monitoring site. The O3 pollution episodes during the measurement period were found to be coincident with the elevation of VOCs, which was mainly due to the air parcel from the southeast direction where petrochemical industry emission was found to be dominant, suggesting that the petrochemical industry emission from the southeast was probably a significant cause of O3 pollution in Shenyang.
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Affiliation(s)
- Zhuobiao Ma
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chengtang Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chenglong Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Pengfei Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Can Ye
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chaoyang Xue
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Di Zhao
- Shenyang Academy of Environmental Sciences, Shenyang 110167, China
| | - Jichen Sun
- Shenyang Academy of Environmental Sciences, Shenyang 110167, China
| | - Yiming Du
- Shenyang Environmental Monitoring Centre, Shenyang 110000, China
| | - Fahe Chai
- Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yujing Mu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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13
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Rate Constants for the Reaction of OH Radicals with Hydrocarbons in a Smog Chamber at Low Atmospheric Temperatures. ATMOSPHERE 2018. [DOI: 10.3390/atmos9080320] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The photochemical reaction of OH radicals with the 17 hydrocarbons n-butane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, cyclooctane, 2,2-dimethylbutane, 2,2-dimethylpentane, 2,2-dimethylhexane, 2,2,4-trimethylpentane, 2,2,3,3-tetramethylbutane, benzene, toluene, ethylbenzene, p-xylene, and o-xylene was investigated at 288 and 248 K in a temperature controlled smog chamber. The rate constants were determined from relative rate calculations with toluene and n-pentane as reference compounds, respectively. The results from this work at 288 K show good agreement with previous literature data for the straight-chain hydrocarbons, as well as for cyclooctane, 2,2-dimethylbutane, 2,2,4-trimethylpentane, 2,2,3,3-tetramethylbutane, benzene, and toluene, indicating a convenient method to study the reaction of OH radicals with many hydrocarbons simultaneously. The data at 248 K (k in units of 10−12 cm3 s−1) for 2,2-dimethylpentane (2.97 ± 0.08), 2,2-dimethylhexane (4.30 ± 0.12), 2,2,4-trimethylpentane (3.20 ± 0.11), and ethylbenzene (7.51 ± 0.53) extend the available data range of experiments. Results from this work are useful to evaluate the atmospheric lifetime of the hydrocarbons and are essential for modeling the photochemical reactions of hydrocarbons in the real troposphere.
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14
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Lin CC, Chen WY, Matsui H, Wang NS. Direct measurement of site-specific rates of reactions of H with C 3H 8, i-C 4H 10, and n-C 4H 10. J Chem Phys 2017; 147:064304. [PMID: 28810788 DOI: 10.1063/1.4997739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We measured the rates of abstraction of a hydrogen atom from specific sites in propane C3H8, 2-methyl propane (i-C4H10), and butane (n-C4H10); the sites are a primary hydrogen of C3H8 and i-C4H10 and a secondary hydrogen of n-C4H10. The excellent reproducibility of conditions of a diaphragm-less shock tube enabled us to conduct comparative measurements of the evolution of H atoms in three mixtures-(i) 0.5 ppm C2H5I + Ar, (ii) 0.5 ppm C2H5I + 50-100 ppm alkane as C3H8 or i-C4H10 or n-C4H10 + Ar, and (iii) the same concentrations of alkane + Ar without C2H5I-in the temperature range 1000-1200 K and at a pressure of 2.0 bars. The net profile of rise and decay of H atoms in the C2H5I + alkane mixture was derived on subtracting the absorbance of (iii) from that of (ii). Measurements of the mixture (iii) are important because the absorption of alkanes at 121.6 nm is not negligible. In the temperature range 1000-1100 K, the rate of decomposition of C2H5I was evaluated directly on analyzing the exponential growth of H atoms in the mixture (i). The rate of decomposition of C2H5I is summarized as ln(k/s-1) = (33.12 ± 1.4) - (25.23 ± 1.5) 103/T (T = 1000-1100 K, P = 2.0 bars); the broadening factor F(T) in the Lindemann-Hinshelwood formula was evaluated in the fall-off region. The site-specific rates of H + (C3-C4) alkanes are summarized as follows: H + C3H8 → H2 + 1-C3H7, ln(k1a) = -(21.34 ± 0.86) - (5.39 ± 0.93)103/T, H + i-C4H10 → H2 + i-C4H9, ln(k2a) = -(20.50 ± 1.36) - (6.14 ± 0.13)103/T, H + n-C4H10 → H2 + 2-C4H9, ln(k3b) = -(21.37 ± 1.15) - (4.83 ± 1.26)103/T. The present experimental results are compared with published results from quantum-chemical calculations of potential-energy surfaces and transition-state theory. The present experiments are consistent with those calculations for the reaction rates for the attack at the primary site for H + C3H8 and H + i-C4H10, but for the attack at the secondary site of n-C4H10, our results are substantially smaller than the computational prediction, which might indicate a hindrance by the C-H bonds of the primary sites that serves to decrease the rate of abstraction from the secondary site of n-C4H10. The influence on the total rates of reactions H + alkane and the group additivity rule are discussed.
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Affiliation(s)
- Chia-Chieh Lin
- Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan
| | - Wei-Yu Chen
- Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan
| | - Hiroyuki Matsui
- Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan
| | - Niann-Shiah Wang
- Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 30010, Taiwan
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15
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Kovacevic G, Sabljic A. Atmospheric oxidation of halogenated aromatics: comparative analysis of reaction mechanisms and reaction kinetics. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2017; 19:357-369. [PMID: 28002503 DOI: 10.1039/c6em00577b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atmospheric transport is the major route for global distribution of semi-volatile compounds such as halogenated aromatics as well as their major exposure route for humans. Their major atmospheric removal process is oxidation by hydroxyl radicals. There is very little information on the reaction mechanism or reaction-path dynamics of atmospheric degradation of halogenated benzenes. Furthermore, the measured reaction rate constants are missing for the range of environmentally relevant temperatures, i.e. 230-330 K. A series of recent theoretical studies have provided those valuable missing information for fluorobenzene, chlorobenzene, hexafluorobenzene and hexachlorobenzene. Their comparative analysis has provided additional and more general insight into the mechanism of those important tropospheric degradation processes as well as into the mobility, transport and atmospheric fate of halogenated aromatic systems. It was demonstrated for the first time that the addition of hydroxyl radicals to monohalogenated as well as to perhalogenated benzenes proceeds indirectly, via a prereaction complex and its formation and dynamics have been characterized including the respective transition-state. However, in fluorobenzene and chlorobenzene reactions hydroxyl radical hydrogen is pointing approximately to the center of the aromatic ring while in the case of hexafluorobenzene and hexachlorobenzene, unexpectedly, the oxygen is directed towards the center of the aromatic ring. The reliable rate constants are now available for all environmentally relevant temperatures for the tropospheric oxidation of fluorobenzene, chlorobenzene, hexafluorobenzene and hexachlorobenzene while pentachlorophenol, a well-known organic micropollutant, seems to be a major stable product of tropospheric oxidation of hexachlorobenzene. Their calculated tropospheric lifetimes show that fluorobenzene and chlorobenzene are easily removed from the atmosphere and do not have long-range transport potential while hexafluorobenzene seems to be a potential POP chemical and hexachlorobenzene is clearly a typical persistent organic pollutant.
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Affiliation(s)
- Goran Kovacevic
- Rudjer Boskovic Institute, Division of Physical Chemistry, POB 180, HR-10002 Zagreb, Republic of Croatia.
| | - Aleksandar Sabljic
- Rudjer Boskovic Institute, Division of Physical Chemistry, POB 180, HR-10002 Zagreb, Republic of Croatia.
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16
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Liu D, Khaled F, Giri BR, Assaf E, Fittschen C, Farooq A. H-Abstraction by OH from Large Branched Alkanes: Overall Rate Measurements and Site-Specific Tertiary Rate Calculations. J Phys Chem A 2017; 121:927-937. [PMID: 28071058 DOI: 10.1021/acs.jpca.6b10576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction rate coefficients for the reaction of hydroxyl (OH) radicals with nine large branched alkanes (i.e., 2-methyl-3-ethyl-pentane, 2,3-dimethyl-pentane, 2,2,3-trimethylbutane, 2,2,3-trimethyl-pentane, 2,3,4-trimethyl-pentane, 3-ethyl-pentane, 2,2,3,4-tetramethyl-pentane, 2,2-dimethyl-3-ethyl-pentane, and 2,4-dimethyl-3-ethyl-pentane) are measured at high temperatures (900-1300 K) using a shock tube and narrow-line-width OH absorption diagnostic in the UV region. In addition, room-temperature measurements of six out of these nine rate coefficients are performed in a photolysis cell using high repetition laser-induced fluorescence of OH radicals. Our experimental results are combined with previous literature measurements to obtain three-parameter Arrhenius expressions valid over a wide temperature range (300-1300 K). The rate coefficients are analyzed using the next-nearest-neighbor (N-N-N) methodology to derive nine tertiary (T003, T012, T013, T022, T023, T111, T112, T113, and T122) site-specific rate coefficients for the abstraction of H atoms by OH radicals from branched alkanes. Derived Arrhenius expressions, valid over 950-1300 K, are given as (the subscripts denote the number of carbon atoms connected to the next-nearest-neighbor carbon): T003 = 1.80 × 10-10 exp(-2971 K/T) cm3 molecule-1 s-1; T012 = 9.36 × 10-11 exp(-3024 K/T) cm3 molecule-1 s-1; T013 = 4.40 × 10-10 exp(-4162 K/T) cm3 molecule-1 s-1; T022 = 1.47 × 10-10 exp(-3587 K/T) cm3 molecule-1 s-1; T023 = 6.06 × 10-11 exp(-3010 K/T) cm3 molecule-1 s-1; T111 = 3.98 × 10-11 exp(-1617 K/T) cm3 molecule-1 s-1; T112 = 9.08 × 10-12 exp(-3661 K/T) cm3 molecule-1 s-1; T113 = 6.74 × 10-9 exp(-7547 K/T) cm3 molecule-1 s-1; T122 = 3.47 × 10-11 exp(-1802 K/T) cm3 molecule-1 s-1.
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Affiliation(s)
- Dapeng Liu
- Clean Combustion Research Center, King Abdullah University of Science and Technology , Thuwal 23955, Kingdom of Saudi Arabia
| | - Fethi Khaled
- Clean Combustion Research Center, King Abdullah University of Science and Technology , Thuwal 23955, Kingdom of Saudi Arabia
| | - Binod R Giri
- Clean Combustion Research Center, King Abdullah University of Science and Technology , Thuwal 23955, Kingdom of Saudi Arabia
| | - Emmanuel Assaf
- Université Lille , CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France
| | - Christa Fittschen
- Université Lille , CNRS, UMR 8522 - PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000 Lille, France
| | - Aamir Farooq
- Clean Combustion Research Center, King Abdullah University of Science and Technology , Thuwal 23955, Kingdom of Saudi Arabia
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17
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Diamanti A, Adjiman CS, Piccione PM, Rea AM, Galindo A. Development of Predictive Models of the Kinetics of a Hydrogen Abstraction Reaction Combining Quantum-Mechanical Calculations and Experimental Data. Ind Eng Chem Res 2017. [DOI: 10.1021/acs.iecr.6b03443] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aikaterini Diamanti
- Centre
for Process Systems Engineering, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Claire S. Adjiman
- Centre
for Process Systems Engineering, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Patrick M. Piccione
- Process
Studies Group, Technology and Engineering, Syngenta, Breitenloh
5, 4333 Münchwilen, Switzerland
| | - Anita M. Rea
- Process
Studies Group, Technology and Engineering, Syngenta, Jealotts Hill International Research Center, Bracknell, Berkshire RG42
6EY, United Kingdom
| | - Amparo Galindo
- Centre
for Process Systems Engineering, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
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18
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Porada E, Szyszkowicz M. UNMIX Methods Applied to Characterize Sources of Volatile Organic Compounds in Toronto, Ontario. TOXICS 2016; 4:E11. [PMID: 29051416 PMCID: PMC5606629 DOI: 10.3390/toxics4020011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/17/2016] [Accepted: 06/07/2016] [Indexed: 11/30/2022]
Abstract
UNMIX, a sensor modeling routine from the U.S. Environmental Protection Agency (EPA), was used to model volatile organic compound (VOC) receptors in four urban sites in Toronto, Ontario. VOC ambient concentration data acquired in 2000-2009 for 175 VOC species in four air quality monitoring stations were analyzed. UNMIX, by performing multiple modeling attempts upon varying VOC menus-while rejecting the results that were not reliable-allowed for discriminating sources by their most consistent chemical characteristics. The method assessed occurrences of VOCs in sources typical of the urban environment (traffic, evaporative emissions of fuels, banks of fugitive inert gases), industrial point sources (plastic-, polymer-, and metalworking manufactures), and in secondary sources (releases from water, sediments, and contaminated urban soil). The remote sensing and robust modeling used here produces chemical profiles of putative VOC sources that, if combined with known environmental fates of VOCs, can be used to assign physical sources' shares of VOCs emissions into the atmosphere. This in turn provides a means of assessing the impact of environmental policies on one hand, and industrial activities on the other hand, on VOC air pollution.
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Affiliation(s)
- Eugeniusz Porada
- Department of Computer Science, University of Québec at Outaouais, Gatineau, QB J8X 3X7, Canada.
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19
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Tesa-Serrate MA, Smoll EJ, Minton TK, McKendrick KG. Atomic and Molecular Collisions at Liquid Surfaces. Annu Rev Phys Chem 2016; 67:515-40. [PMID: 27090845 DOI: 10.1146/annurev-physchem-040215-112355] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The gas-liquid interface remains one of the least explored, but nevertheless most practically important, environments in which molecular collisions take place. These molecular-level processes underlie many bulk phenomena of fundamental and applied interest, spanning evaporation, respiration, multiphase catalysis, and atmospheric chemistry. We review here the research that has, during the past decade or so, been unraveling the molecular-level mechanisms of inelastic and reactive collisions at the gas-liquid interface. Armed with the knowledge that such collisions with the outer layers of the interfacial region can be unambiguously distinguished, we show that the scattering of gas-phase projectiles is a promising new tool for the interrogation of liquid surfaces with extreme surface sensitivity. Especially for reactive scattering, this method also offers absolute chemical selectivity for the groups that react to produce a specific observed product.
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Affiliation(s)
- Maria A Tesa-Serrate
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom;
| | - Eric J Smoll
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717;
| | - Timothy K Minton
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717;
| | - Kenneth G McKendrick
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom;
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20
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Allison TC. Application of an Artificial Neural Network to the Prediction of OH Radical Reaction Rate Constants for Evaluating Global Warming Potential. J Phys Chem B 2015; 120:1854-63. [PMID: 26684219 DOI: 10.1021/acs.jpcb.5b09558] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rate constants for reactions of chemical compounds with hydroxyl radical are a key quantity used in evaluating the global warming potential of a substance. Experimental determination of these rate constants is essential, but it can also be difficult and time-consuming to produce. High-level quantum chemistry predictions of the rate constant can suffer from the same issues. Therefore, it is valuable to devise estimation schemes that can give reasonable results on a variety of chemical compounds. In this article, the construction and training of an artificial neural network (ANN) for the prediction of rate constants at 298 K for reactions of hydroxyl radical with a diverse set of molecules is described. Input to the ANN consists of counts of the chemical bonds and bends present in the target molecule. The ANN is trained using 792 (•)OH reaction rate constants taken from the NIST Chemical Kinetics Database. The mean unsigned percent error (MUPE) for the training set is 12%, and the MUPE of the testing set is 51%. It is shown that the present methodology yields rate constants of reasonable accuracy for a diverse set of inputs. The results are compared to high-quality literature values and to another estimation scheme. This ANN methodology is expected to be of use in a wide range of applications for which (•)OH reaction rate constants are required. The model uses only information that can be gathered from a 2D representation of the molecule, making the present approach particularly appealing, especially for screening applications.
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Affiliation(s)
- Thomas C Allison
- Chemical Informatics Research Group, Material Measurement Laboratory, National Institute of Standards and Technology , 100 Bureau Drive, Stop 8320, Gaithersburg, Maryland 20899-8320, United States
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21
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Morin J, Romanias MN, Bedjanian Y. Experimental Study of the Reactions of OH Radicals with Propane, n
-Pentane, and n
-Heptane over a Wide Temperature Range. INT J CHEM KINET 2015. [DOI: 10.1002/kin.20936] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Julien Morin
- Institut de Combustion; Aérothermique; Réactivité et Environnement (ICARE); CNRS and Université d'Orléans; 45071 Orléans Cedex 2 France
| | - Manolis N. Romanias
- Institut de Combustion; Aérothermique; Réactivité et Environnement (ICARE); CNRS and Université d'Orléans; 45071 Orléans Cedex 2 France
| | - Yuri Bedjanian
- Institut de Combustion; Aérothermique; Réactivité et Environnement (ICARE); CNRS and Université d'Orléans; 45071 Orléans Cedex 2 France
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22
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Ballesteros B, Ceacero-Vega AA, Jiménez E, Albaladejo J. Atmospheric reactions of methylcyclohexanes with Cl atoms and OH radicals: determination of rate coefficients and degradation products. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:4806-4819. [PMID: 24788931 DOI: 10.1007/s11356-014-2901-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/07/2014] [Indexed: 06/03/2023]
Abstract
As the result of biogenic and anthropogenic activities, large quantities of chemical compounds are emitted into the troposphere. Alkanes, in general, and cycloalkanes are an important chemical class of hydrocarbons found in diesel, jet and gasoline, vehicle exhaust emissions, and ambient air in urban areas. In general, the primary atmospheric fate of organic compounds in the gas phase is the reaction with hydroxyl radicals (OH). The oxidation by Cl atoms has gained importance in the study of atmospheric reactions because they may exert some influence in the boundary layer, particularly in marine and coastal environments, and in the Arctic troposphere. The aim of this paper is to study of the atmospheric reactivity of methylcylohexanes with Cl atoms and OH radicals under atmospheric conditions (in air at room temperature and pressure). Relative kinetic techniques have been used to determine the rate coefficients for the reaction of Cl atoms and OH radicals with methylcyclohexane, cis-1,4-dimethylcyclohexane, trans-1,4-dimethylcyclohexane, and 1,3,5-trimethylcyclohexane at 298 ± 2 K and 720 ± 5 Torr of air by Fourier transform infrared) spectroscopy and gas chromatography-mass spectrometry (GC-MS) in two atmospheric simulation chambers. The products formed in the reaction under atmospheric conditions were investigated using a 200-L Teflon bag and employing the technique of solid-phase microextraction coupled to a GC-MS. The rate coefficients obtained for the reaction of Cl atoms with the studied compounds are the following ones (in units of 10(-10) cm(3) molecule(-1) s(-1)): (3.11 ± 0.16), (2.89 ± 0.16), (2.89 ± 0.26), and (2.61 ± 0.42), respectively. For the reactions with OH radicals the determined rate coefficients are (in units of 10(-11) cm(3) molecule(-1) s(-1)): (1.18 ± 0.12), (1.49 ± 0.16), (1.41 ± 0.15), and (1.77 ± 0.23), respectively. The reported error is twice the standard deviation. A detailed mechanism for ring-retaining product channels is proposed to justify the observed reaction products. The global tropospheric lifetimes estimated from the reported OH- and Cl-rate coefficients show that the main removal path for the investigated methylcyclohexanes is the reaction with OH radicals. But in marine environments, after sunrise, Cl reactions become more important in the tropospheric degradation. Thus, the estimated lifetimes range from 16 to 24 h for the reactions of the OH radical (calculated with [OH] = 10(6) atoms cm(-3)) and around 7-8 h in the reactions with Cl atoms in marine environments (calculated with [Cl] = 1.3 × 10(5) atoms cm(-3)). The reaction of Cl atoms and OH radicals and methylcylohexanes can proceed by H abstraction from the different positions.
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Affiliation(s)
- Bernabé Ballesteros
- Department of Physical Chemistry, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain
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23
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Priya AM, El Dib G, Senthilkumar L, Sleiman C, Tomas A, Canosa A, Chakir A. An experimental and theoretical study of the kinetics of the reaction between 3-hydroxy-3-methyl-2-butanone and OH radicals. RSC Adv 2015. [DOI: 10.1039/c4ra15664a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Absolute experimental and theoretical rate constants are determined for the first time for the reaction of 3-hydroxy-3-methyl-2-butanone with OH as a function of temperature. The atmospheric implications are discussed.
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Affiliation(s)
| | - Gisèle El Dib
- Institut de Physique de Rennes, (IPR)
- UMR 6251 du CNRS - Université de Rennes 1
- 35042 Rennes Cedex
- France
| | | | - Chantal Sleiman
- Institut de Physique de Rennes, (IPR)
- UMR 6251 du CNRS - Université de Rennes 1
- 35042 Rennes Cedex
- France
| | - Alexandre Tomas
- Mines Douai
- Département Sciences de l'Atmosphère et Génie de l'Environnement
- F-59508 Douai
- France
| | - André Canosa
- Institut de Physique de Rennes, (IPR)
- UMR 6251 du CNRS - Université de Rennes 1
- 35042 Rennes Cedex
- France
| | - Abdelkhaleq Chakir
- Université de Reims
- Laboratoire GSMA-UMR 6089 CNRS
- Campus Moulin de la Housse
- 51687 Reims Cedex 02
- France
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24
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Singh S, de Leon MF, Li Z. Kinetics study of the reaction of OH radicals with C5-C8 cycloalkanes at 240-340 K using the relative rate/discharge flow/mass spectrometry technique. J Phys Chem A 2013; 117:10863-72. [PMID: 24053620 DOI: 10.1021/jp406923d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Rate constants of reactions of hydroxyl radical with cyclopentane (k1), cyclohexane (k2), cycloheptane (k3), and cyclooctane (k4) have been acquired at 240-340 K and a total pressure of about 1 Torr using the technique of relative rate combined with discharge flow and mass spectrometry (RR/DF/MS). At 298 K, the rate constants are determined using two reference compounds, which are averaged to be k1 = (4.81 ± 0.88) × 10(-12), k2 = (6.41 ± 0.85) × 10(-12), k3 = (10.30 ± 1.44) × 10(-12), and k4 = (1.42 ± 0.27) × 10(-11) cm(3) molecule(-1) s(-1). The Arrhenius expressions at 240-340 K for these reactions are determined to be k1(T) = (2.43 ± 0.50) × 10(-11)exp[-(481 ± 58)/T], k2(T) = (3.96 ± 0.60) × 10(-11)exp[-554 ± 42)/T], k3(T) = (5.74 ± 0.66) × 10(-11)exp[-527 ± 33)/T], and k4(T) = (1.12 ± 0.21) × 10(-10)exp[-626 ± 53)/T]. Using the kcycloalkane+OH(277 K) values measured in the present work, the atmospheric lifetime for cyclopentane, cyclohexane, cycloheptane, and cyclooctane is estimated to be about 78, 64, 38, and 29 h, respectively.
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Affiliation(s)
- Sumitpal Singh
- Department of Chemistry and Biochemistry, California State University Fullerton , Fullerton, California 92834, United States
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25
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Kovacevic G, Sabljic A. Mechanisms and reaction-path dynamics of hydroxyl radical reactions with aromatic hydrocarbons: the case of chlorobenzene. CHEMOSPHERE 2013; 92:851-856. [PMID: 23694732 DOI: 10.1016/j.chemosphere.2013.04.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 02/22/2013] [Accepted: 04/15/2013] [Indexed: 06/02/2023]
Abstract
All geometries and energies significant for the first step of tropospheric degradation of chlorobenzene were characterized using the MP2/6-31+G(d,p) and G3 methods. A pre-reaction complex for the addition of OH radical to chlorobenzene was found and the associated transition state was determined for the first time. The reaction path for the association of OH radical and chlorobenzene into the pre-reaction complex was extrapolated from the selected low frequency normal mode of pre-reaction complex. The reaction rate constant for addition of OH radical to chlorobenzene was determined for the temperature range 230-330K, using RRKM theory and G3 energies. The calculated rate constants are in agreement with the experimental results. Regioselectivity was also determined for the title reaction from the ratio of respective reaction rates and our results are in very good agreement with the experimental results, which show the dominance of the ortho and para channels as well as a negligible contribution by the ipso channel.
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Affiliation(s)
- Goran Kovacevic
- Institute Rudjer Boskovic, POB 180, HR-10002 Zagreb, Croatia
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26
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Yu AY, Zhang HX. Theoretical studies of the reaction of hydroxyl radical with cyclopentane (C5H10). Mol Phys 2013. [DOI: 10.1080/00268976.2013.817622] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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27
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Poutsma ML. Evolution of Structure–Reactivity Correlations for the Hydrogen Abstraction Reaction by Hydroxyl Radical and Comparison with That by Chlorine Atom. J Phys Chem A 2013; 117:6433-49. [DOI: 10.1021/jp404749z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marvin L. Poutsma
- Chemical Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee
37831-6197, United States
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28
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Blanco MB, Rivela C, Teruel MA. Tropospheric degradation of 2,2,2 trifluoroethyl butyrate: Kinetic study of their reactions with OH radicals and Cl atoms at 298K. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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29
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King KL, Paterson G, Rossi GE, Iljina M, Westacott RE, Costen ML, McKendrick KG. Inelastic scattering of OH radicals from organic liquids: isolating the thermal desorption channel. Phys Chem Chem Phys 2013; 15:12852-63. [DOI: 10.1039/c3cp51708j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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30
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El Dib G, Sleiman C, Canosa A, Travers D, Courbe J, Sawaya T, Mokbel I, Chakir A. First Experimental Determination of the Absolute Gas-Phase Rate Coefficient for the Reaction of OH with 4-Hydroxy-2-Butanone (4H2B) at 294 K by Vapor Pressure Measurements of 4H2B. J Phys Chem A 2012; 117:117-25. [DOI: 10.1021/jp3074909] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Gisèle El Dib
- Département de
Physique Moléculaire, Institut de Physique de
Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11 C, Campus de Beaulieu, 35042 Rennes Cedex,
France
| | - Chantal Sleiman
- Département de
Physique Moléculaire, Institut de Physique de
Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11 C, Campus de Beaulieu, 35042 Rennes Cedex,
France
| | - André Canosa
- Département de
Physique Moléculaire, Institut de Physique de
Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11 C, Campus de Beaulieu, 35042 Rennes Cedex,
France
| | - Daniel Travers
- Département de
Physique Moléculaire, Institut de Physique de
Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11 C, Campus de Beaulieu, 35042 Rennes Cedex,
France
| | - Jonathan Courbe
- Département de
Physique Moléculaire, Institut de Physique de
Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11 C, Campus de Beaulieu, 35042 Rennes Cedex,
France
| | - Terufat Sawaya
- UMR 5280, Université de Lyon-UCB Lyon 1, 43 bd du
11 Novembre 1918, 69622 Villeurbanne, France
| | - Ilham Mokbel
- UMR 5280, Université de Lyon-UCB Lyon 1, 43 bd du
11 Novembre 1918, 69622 Villeurbanne, France
| | - Abdelkhaleq Chakir
- Laboratoire GSMA, Campus Moulin de la Housse, Université de Reims, BP 1039, 51687 Reims cedex
02, France
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31
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Gennaco MA, Huang YW, Hannun RA, Dransfield TJ. Absolute Rate Constants for the Reaction of OH with Cyclopentane and Cycloheptane from 233 to 351 K. J Phys Chem A 2012. [PMID: 23194446 DOI: 10.1021/jp3048482] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Michael A. Gennaco
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard,
Boston, Massachusetts 02125, United States
| | - Yi-wen Huang
- Department of Earth, Atmospheric
and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United
States
| | - Reem A. Hannun
- Department of Chemistry
and Chemical
Biology, Harvard University, 12 Oxford
Street, Cambridge, Massachusetts 02139, United States
| | - Timothy J. Dransfield
- Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard,
Boston, Massachusetts 02125, United States
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32
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Miller JB, Lehman SJ, Montzka SA, Sweeney C, Miller BR, Karion A, Wolak C, Dlugokencky EJ, Southon J, Turnbull JC, Tans PP. Linking emissions of fossil fuel CO2and other anthropogenic trace gases using atmospheric14CO2. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd017048] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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33
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Paterson G, Relf A, Costen ML, McKendrick KG, Alexander MH, Dagdigian PJ. Rotationally elastic and inelastic dynamics of NO(X2Π, v = 0) in collisions with Ar. J Chem Phys 2011; 135:234304. [PMID: 22191872 DOI: 10.1063/1.3665135] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A combined theoretical and experimental study of the depolarization of selected NO(X(2)Π, v = 0, j, F, ɛ) levels in collisions with a thermal bath of Ar has been carried out. Rate constants for elastic depolarization of rank K = 1 (orientation) and K = 2 (alignment) were extracted from collision-energy-dependent quantum scattering calculations, along with those for inelastic population transfer to discrete product levels. The rate constants for total loss of polarization of selected initial levels, which are the sum of elastic depolarization and population transfer contributions, were measured using a two-color polarization spectroscopy technique. Theory and experiment agree qualitatively that the rate constants for total loss of polarization decline modestly with j, but the absolute values differ by significantly more than the statistical uncertainties in the measurements. The reasons for this discrepancy are as yet unclear. The lack of a significant K dependence in the experimental data is, however, consistent with the theoretical prediction that elastic depolarization makes only a modest contribution to the total loss of polarization. This supports a previous conclusion that elastic depolarization for NO(X(2)Π) + Ar is significantly less efficient than for the electronically closely related system OH(X(2)Π) + Ar [P. J. Dagdigian and M. H. Alexander, J. Chem. Phys. 130, 204304 (2009)].
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Affiliation(s)
- G Paterson
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
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Aschmann SM, Arey J, Atkinson R. Reactions of OH Radicals with C6–C10 Cycloalkanes in the Presence of NO: Isomerization of C7–C10 Cycloalkoxy Radicals. J Phys Chem A 2011; 115:14452-61. [DOI: 10.1021/jp209654h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sara M. Aschmann
- Air Pollution Research Center, ‡Department of Environmental Sciences, and §Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Janet Arey
- Air Pollution Research Center, ‡Department of Environmental Sciences, and §Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Roger Atkinson
- Air Pollution Research Center, ‡Department of Environmental Sciences, and §Department of Chemistry, University of California, Riverside, California 92521, United States
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Pang GA, Hanson RK, Golden DM, Bowman CT. High-Temperature Measurements of the Rate Constants for Reactions of OH with a Series of Large Normal Alkanes: n-Pentane, n-Heptane, and n-Nonane. ACTA ACUST UNITED AC 2011. [DOI: 10.1524/zpch.2011.0156] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Rate constants for the overall reactions of OH with n-pentane, n-heptane, and n-nonane were measured in shock tube experiments behind reflected shock waves. Narrow-linewidth laser absorption by OH at 306.7 nm was used in pseudo first-order experiments with temperatures between 869 to 1364 K. tert-Butyl hydroperoxide (TBHP) was used as the OH precursor. Experiments were also performed to study the kinetics of the TBHP decomposition and resulting product chemistry, and an accurate mechanism describing OH precursor chemistry effects was developed to model OH concentration time-history in the n-alkane + OH experiments. The experimental results for the n-alkane + OH rate constant measurements can be expressed as rate constants in Arrhenius form as
k
n-pentane + OH = 2.10 × 10-10 exp(-2038/T[K]) (869–1364 K),
k
n-heptane + OH = 2.43 × 10-10 exp(-1804/T[K]) (869–1364 K),
k
n-nonane + OH = 3.17 × 10-10 exp(-1801/T[K]) (884–1352 K),
each in units of cm3 molecule-1 s-1. The present rate constants measured for OH with n-pentane and n-heptane show agreement within 20% with recent work by Sivaramakrishnan and Michael [J. Phys. Chem. A, 113 (2009) 5047]. The measurements of the rate constant for n-nonane + OH presented here represent the first in the literature to depict the temperature dependence of the rate constant above 800 K. The measurements of each n-alkane + OH rate constant studied were compared with two models in the literature used to estimate the rate constants of n-alkane + OH reactions. The Structure-Activity Relationship of Kwok and Atkinson [Atmos. Environ., 29 (1995) 1685] shows the best agreement with the current data for all three n-alkanes over the entire temperature range studied, demonstrating that this model is capable of predicting the overall rate constants for reactions of OH with n-pentane, n-heptane, and n-nonane for temperatures up to 1364 K.
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Affiliation(s)
| | - Ronald K. Hanson
- Stanford University, Mechanical Engineering Department, Stanford, CA 94305, U.S.A
| | - David M. Golden
- Stanford University, Department of Mechanical Engineering, Stanford CA 94305, U.S.A
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36
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Cardozo M, Ordoñez R, Alberto M, Zampini I, Isla M. Antioxidant and anti-inflammatory activity characterization and genotoxicity evaluation of Ziziphus mistol ripe berries, exotic Argentinean fruit. Food Res Int 2011. [DOI: 10.1016/j.foodres.2011.02.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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37
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Crawford MA, Dang B, Hoang J, Li Z. Kinetic study of OH radical reaction with n
-heptane and n
-hexane at 240-340K using the relative rate/discharge flow/mass spectrometry (RR/DF/MS) technique. INT J CHEM KINET 2011. [DOI: 10.1002/kin.20574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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38
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Ceacero-Vega AA, Ballesteros B, Bejan I, Barnes I, Albaladejo J. Daytime Reactions of 1,8-Cineole in the Troposphere. Chemphyschem 2011; 12:2145-54. [DOI: 10.1002/cphc.201100077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 05/03/2011] [Indexed: 11/07/2022]
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39
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Waring C, King KL, Bagot PAJ, Costen ML, McKendrick KG. Collision dynamics and reactive uptake of OH radicals at liquid surfaces of atmospheric interest. Phys Chem Chem Phys 2011; 13:8457-69. [DOI: 10.1039/c0cp02734k] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Waring C, Bagot PAJ, Slattery JM, Costen ML, McKendrick KG. O(3P) Atoms as a Chemical Probe of Surface Ordering in Ionic Liquids. J Phys Chem A 2010; 114:4896-904. [DOI: 10.1021/jp912045j] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carla Waring
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Paul A. J. Bagot
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - John M. Slattery
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Matthew L. Costen
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
| | - Kenneth G. McKendrick
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K
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41
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Chobot V. Simultaneous detection of pro- and antioxidative effects in the variants of the deoxyribose degradation assay. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:2088-94. [PMID: 20108920 PMCID: PMC2823302 DOI: 10.1021/jf902395k] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Interest in the redox properties of natural products has led to the development of various assays for the detection of antioxidant activities and ROS-scavenging properties. Here, additional modifications of the 2-deoxy-d-ribose degradation assay are introduced that specifically allow the determination of interactions of the test compound with the autoxidation of ascorbic acid and the autoxidation of the test compound itself. To illustrate this, juglone and quercetin were used as examples. The modified assay systems provide insights into their specific antioxidative and pro-oxidative properties. In additional, an extensive characterization of the redox properties of their complex with iron is possible, if iron ions are added in the free form or complexed with EDTA. The juglone-iron complex proved to be pro-oxidative in a wider range of milieus than the quercetin-iron complex.
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Affiliation(s)
- Vladimir Chobot
- Department of Chemical Ecology and Ecosystem Research, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
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42
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Hoyermann K, Maarfeld S, Nacke F, Nothdurft J, Olzmann M, Wehmeyer J, Welz O, Zeuch T. Rate coefficients for cycloalkyl + O reactions and product branching in the decomposition of chemically activated cycloalkoxy radicals: an experimental and theoretical study. Phys Chem Chem Phys 2010; 12:8953-67. [DOI: 10.1039/b925920a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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43
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Sivaramakrishnan R, Michael JV. Rate Constants for OH with Selected Large Alkanes: Shock-Tube Measurements and an Improved Group Scheme. J Phys Chem A 2009; 113:5047-60. [DOI: 10.1021/jp810987u] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- R. Sivaramakrishnan
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - J. V. Michael
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439
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44
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Sprengnether MM, Demerjian KL, Dransfield TJ, Clarke JS, Anderson JG, Donahue NM. Rate Constants of Nine C6−C9 Alkanes with OH from 230 to 379 K: Chemical Tracers for [OH]. J Phys Chem A 2009; 113:5030-8. [DOI: 10.1021/jp810412m] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Timothy J. Dransfield
- Department of Chemistry, University of Massachusetts, 100 Morrissey Blvd., Boston, Massachusetts, 02125
| | | | | | - Neil M. Donahue
- Center for Atmospheric Particle Studies, Doherty Hall B204, Carnegie Mellon University, Pittsburgh, Pennsylvania, 15213
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45
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Li Z, Singh S, Woodward W, Dang L. Kinetics study of OH radical reactions with n-octane, n-nonane, and n-decane at 240-340 K using the relative rate/discharge flow/mass spectrometry technique. J Phys Chem A 2007; 110:12150-7. [PMID: 17078610 DOI: 10.1021/jp0638134] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The kinetics of the reactions of hydroxyl radical with n-octane (k1), n-nonane (k2), and n-decane (k3) at 240-340 K and a total pressure of approximately 1 Torr has been studied using relative rate combined with discharge flow and mass spectrometer (RR/DF/MS) technique. The rate constant for these reactions was found to be positively dependent on temperature, with an Arrhenius expression of k1 = (2.27 +/- 0.21) x 10(-11)exp[(-296 +/- 27)/T], k2 = (4.35 +/- 0.49) x 10(-11)exp[(-411 +/- 32)/T], and k3 = (2.26 +/- 0.28) x 10(-11)exp[(-160 +/- 36)/T] cm3 molecule(-1) s(-1) (uncertainties taken as 2sigma), respectively. Our results are in good agreement with previous studies at and above room temperature using different techniques. Assuming that the reaction of alkane with hydroxyl radical is the predominant form for loss of these alkanes in the troposphere, the atmospheric lifetime for n-octane, n-nonane, and n-decane is estimated to be about 43, 35, and 28 h, respectively.
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Affiliation(s)
- Zhuangjie Li
- Department of Chemistry and Biochemistry, California State University Fullerton, Fullerton, California 92834, USA.
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46
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Yu HG. Ab initio molecular dynamics simulation of photodetachment reaction of cyclopentoxide. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.04.079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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47
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Wilson EW, Hamilton WA, Mount HR, DeMore WB. Rate Constants for the Reactions of Hydroxyl Radical with Several Fluoroethers by the Relative Rate Method. J Phys Chem A 2007; 111:1610-7. [PMID: 17295462 DOI: 10.1021/jp068355d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Relative rate experiments were used to measure ratios of chemical kinetics rate constants as a function of temperature for the reactions of OH with eight fluoroethers, including CF3OCF2CHF2, CF3OCF2CHFCF3, CHF2CF2OCHF2, CF3CHFCF2OCH2CF3, (CF3)2CHOCHF2, CF2HCF2OCH2CF3, CHF2CF2OCHFCF3, and CF3CH2OCH2CF3. The temperature ranges were about 270-400 K. Each compound was measured against at least two references. Results are compared with previous data where available. An approach using model compounds for the approximate estimation of rate constants for the fluoroethers is discussed. Observed temperature dependences for fluoroethers from the present work and some literature work are shown to be accurately predictable, based on a previously determined correlation of k298K with the pre-exponential factor, A, in the Arrhenius equation k = Ae(-E/RT).
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Affiliation(s)
- Edmond W Wilson
- Department of Physical Science, Harding University, Mail Stop 10849, 915 East Market Avenue, Searcy, AR 72149, USA.
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