1
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Frederiks NC, Johnson CJ. Photochemical Mechanisms in Atmospherically Relevant Iodine Oxide Clusters. J Phys Chem Lett 2024; 15:6306-6314. [PMID: 38856106 DOI: 10.1021/acs.jpclett.4c01324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Atmospheric new particle formation events can be driven by iodine oxides or oxoacids via both neutral and ionic mechanisms. Photolysis of new particles likely plays a significant role in their growth mechanisms, but their spectra and photolysis mechanisms remain difficult to characterize. We recorded ultraviolet (UV) photodissociation spectra of (I2O5)0-3(IO3-) clusters, observing loss of an O atom, I2O4, and (I2O5)1,2 in the atmospherically relevant range of 300-340 nm. With increasing cluster size, the intensity of absorption red shifts and generally increases, suggesting particles photolyze more frequently as they grow. Estimates of the rates indicate that even relatively small clusters are likely to undergo photolysis under high-UV conditions. Vibrational spectra identify the covalent moiety I3O8- as the likely chromophore, not IO3-. The I2O5 loss pathway competes with particle growth, while the slower O loss pathway likely produces 3O + 3(cluster) products that could drive subsequent intraparticle chemistry, particularly with co-adsorbed organic or amine species.
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Affiliation(s)
- Nicoline C Frederiks
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Christopher J Johnson
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
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2
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Chao W, Markus CR, Okumura M, Winiberg FAF, Percival CJ. Chemical Kinetic Study of the Reaction of CH 2OO with CH 3O 2. J Phys Chem Lett 2024; 15:3690-3697. [PMID: 38546268 DOI: 10.1021/acs.jpclett.4c00159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Criegee intermediates play an important role in the oxidizing capacity of the Earth's troposphere. Although extensive studies have been conducted on Criegee intermediates in the past decade, their kinetics with radical species remain underexplored. We investigated the kinetics of the simplest Criegee intermediate, CH2OO, with the methyl peroxy radical, CH3O2, as a model system to explore the reactivities of Criegee intermediates with peroxy radicals. Using a multipass UV-Vis spectrometer coupled to a pulsed-laser photolysis flow reactor, CH2OO and CH3O2 were generated simultaneously from the photolysis of CH2I2/CH3I/O2/N2 mixtures with CH2OO measured directly near 340 nm. We determined a reaction rate coefficient kCH2OO+CH3O2 = (1.7 ± 0.5) × 10-11 cm3 s-1 at 294 K and 10 Torr, where the influence of iodine adducts is reduced. This rate coefficient is faster than previous theoretical predictions, highlighting the challenges in accurately describing the interaction between zwitterionic and biradical characteristics of Criegee intermediates.
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Affiliation(s)
- Wen Chao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States
| | - Charles R Markus
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, United States
| | - Mitchio Okumura
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, California 91125, United States
| | - Frank A F Winiberg
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, United States
| | - Carl J Percival
- NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, United States
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3
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Cornwell Z, Enders JJ, Harrison AW, Murray C. Temperature-Dependent Kinetics of the Reactions of the Criegee Intermediate CH 2OO with Hydroxyketones. J Phys Chem A 2024; 128:1880-1891. [PMID: 38428028 PMCID: PMC10945482 DOI: 10.1021/acs.jpca.4c00156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/03/2024]
Abstract
Though there is a growing body of literature on the kinetics of CIs with simple carbonyls, CI reactions with functionalized carbonyls such as hydroxyketones remain unexplored. In this work, the temperature-dependent kinetics of the reactions of CH2OO with two hydroxyketones, hydroxyacetone (AcOH) and 4-hydroxy-2-butanone (4H2B), have been studied using a laser flash photolysis transient absorption spectroscopy technique and complementary quantum chemistry calculations. Bimolecular rate constants were determined from CH2OO loss rates observed under pseudo-first-order conditions across the temperature range 275-335 K. Arrhenius plots were linear and yielded T-dependent bimolecular rate constants: kAcOH(T) = (4.3 ± 1.7) × 10-15 exp[(1630 ± 120)/T] and k4H2B(T) = (3.5 ± 2.6) × 10-15 exp[(1700 ± 200)/T]. Both reactions show negative temperature dependences and overall very similar rate constants. Stationary points on the reaction energy surfaces were characterized using the composite CBS-QB3 method. Transition states were identified for both 1,3-dipolar cycloaddition reactions across the carbonyl and 1,2-insertion/addition at the hydroxyl group. The free-energy barriers for the latter reaction pathways are higher by ∼4-5 kcal mol-1, and their contributions are presumed to be negligible for both AcOH and 4H2B. The cycloaddition reactions are highly exothermic and form cyclic secondary ozonides that are the typical primary products of Criegee intermediate reactions with carbonyl compounds. The reactivity of the hydroxyketones toward CH2OO appears to be similar to that of acetaldehyde, which can be rationalized by consideration of the energies of the frontier molecular orbitals involved in the cycloaddition. The CH2OO + hydroxyketone reactions are likely too slow to be of significance in the atmosphere, except at very low temperatures.
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Affiliation(s)
- Zachary
A. Cornwell
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
| | - Jonas J. Enders
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
| | - Aaron W. Harrison
- Department
of Chemistry, Austin College, Sherman, Texas 75090, United States
| | - Craig Murray
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
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4
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Lin YH, Takahashi K, Lin JJM. Comment on "UV Absorption Spectroscopy of the Conformer-Dependent Reactivity of the Four Carbon Criegee Intermediate of Methyl Vinyl Ketone Oxide: An Ab initio Quantum Dynamics Study". J Phys Chem A 2024; 128:972-973. [PMID: 38291958 PMCID: PMC10860122 DOI: 10.1021/acs.jpca.4c00105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 01/25/2024] [Indexed: 02/01/2024]
Affiliation(s)
- Yen-Hsiu Lin
- Institute
of Atomic and Molecular Sciences, Academia
Sinica, Taipei 106319, Taiwan
- Department
of Chemistry, National Taiwan University, Taipei 106319, Taiwan
| | - Kaito Takahashi
- Institute
of Atomic and Molecular Sciences, Academia
Sinica, Taipei 106319, Taiwan
| | - Jim Jr-Min Lin
- Institute
of Atomic and Molecular Sciences, Academia
Sinica, Taipei 106319, Taiwan
- Department
of Chemistry, National Taiwan University, Taipei 106319, Taiwan
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5
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Winiberg FAF, Chao W, Caravan RL, Markus CR, Sander SP, Percival CJ. A white cell based broadband transient UV-vis absorption spectroscopy with pulsed laser photolysis reactors for chemical kinetics under variable temperatures and pressures. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:114103. [PMID: 37943165 DOI: 10.1063/5.0164733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/14/2023] [Indexed: 11/10/2023]
Abstract
UV-vis spectroscopy is widely used for kinetic studies in physical chemistry, as species' absolute cross-sections are usually less sensitive to experimental conditions (i.e., temperature and pressure). Here, we present the design and characterization of a multipass UV-vis absorption spectroscopy white cell coupled to a pulsed-laser photolysis flow reactor. The glass reactor was designed to facilitate studies of gas phase chemical reactions over a range of conditions (239-293 K and 10-550 Torr). Purged windows mitigate contamination from chemical precursors and photolysis products. We report the measured impact of this purging on temperature uniformity and the absorption length and present some supporting flow calculations. The combined optical setup is unique and enables the photolysis laser to be coaligned with a well-defined absorption pathlength probe beam. This alignment leverages the use of one long-pass filter to increase the spectrum flatness and increase the light intensity vs other systems that use two dichroic mirrors. The probe beam is analyzed with a dual exit spectrograph, customized to split the light between an intensified CCD and photomultiplier tube, enabling simultaneous spectrum and single wavelength detection. This multipass system yields a pathlength of ∼450 cm and minimum observable concentrations of ∼3.7 × 1011 molecule cm-3 (assuming cross-sections ∼1.2 × 10-17 cm2). The temperature profile across the reaction region is ±2 K, defined by the worst-case temperature of 239 K, validated by measurements of the N2O4 equilibrium constant. Finally, the system is implemented to study the simplest Criegee intermediate, demonstrating the instrument performance and advantages of simultaneous spectrum and temporal profile measurements.
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Affiliation(s)
- Frank A F Winiberg
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA
| | - Wen Chao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, California 91125, USA
| | - Rebecca L Caravan
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA
| | - Charles R Markus
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, California 91125, USA
| | - Stanley P Sander
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA
| | - Carl J Percival
- Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099, USA
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6
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Wu YJ, Takahashi K, Lin JJM. Kinetics of the Simplest Criegee Intermediate Reaction with Water Vapor: Revisit and Isotope Effect. J Phys Chem A 2023; 127:8059-8072. [PMID: 37734061 DOI: 10.1021/acs.jpca.3c03418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
The kinetics of the simplest Criegee intermediate (CH2OO) reaction with water vapor was revisited. By improving the signal-to-noise ratio and the precision of water concentration, we found that the kinetics of CH2OO involves not only two water molecules but also one and three water molecules. Our experimental results suggest that the decay of CH2OO can be described as d[CH2OO]/dt = -kobs[CH2OO]; kobs = k0 + k1[water] + k2[water]2 + k3[water]3; k1 = (4.22 ± 0.48) × 10-16 cm3 s-1, k2 = (10.66 ± 0.83) × 10-33 cm6 s-1, k3 = (1.48 ± 0.17) × 10-50 cm9 s-1 at 298 K and 300 Torr with the respective Arrhenius activation energies of Ea1 = 1.8 ± 1.1 kcal mol-1, Ea2 = -11.1 ± 2.1 kcal mol-1, Ea3 = -17.4 ± 3.9 kcal mol-1. The contribution of the k3[water]3 term becomes less significant at higher temperatures around 345 K, but it is not ignorable at 298 K and lower temperatures. By quantifying the concentrations of H2O and D2O with a Coriolis-type direct mass flow sensor, the kinetic isotope effect (KIE) was investigated at 298 K and 300 Torr and KIE(k1) = k1(H2O)/k1(D2O) = 1.30 ± 0.32; similarly, KIE(k2) = 2.25 ± 0.44 and KIE(k3) = 0.99 ± 0.13. These mild KIE values are consistent with theoretical calculations based on the variational transition state theory, confirming that the title reaction has a broad and low barrier, and the reaction coordinate involves not only the motion of a hydrogen atom but also that of an oxygen atom. Comparing the results recorded under 300 Torr (N2 buffer gas) with those under 600 Torr, a weak pressure effect of k3 was found. From quantum chemistry calculations, we found that the CH2OO + 3H2O reaction is dominated by the reaction pathways involving a ring structure consisting of two water molecules, which facilitate the hydrogen atom transfer, while the third water molecule is hydrogen-bonded outside the ring. Furthermore, analysis based on dipole capture rates showed that the CH2OO(H2O) + (H2O)2 and CH2OO(H2O)2 + H2O pathways will dominate in the three water reaction.
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Affiliation(s)
- Yen-Ju Wu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106923, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 106923, Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106923, Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106923, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 106923, Taiwan
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7
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Robinson C, Onel L, Newman J, Lade R, Au K, Sheps L, Heard DE, Seakins PW, Blitz MA, Stone D. Unimolecular Kinetics of Stabilized CH 3CHOO Criegee Intermediates: syn-CH 3CHOO Decomposition and anti-CH 3CHOO Isomerization. J Phys Chem A 2022; 126:6984-6994. [PMID: 36146923 PMCID: PMC9549458 DOI: 10.1021/acs.jpca.2c05461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/11/2022] [Indexed: 11/30/2022]
Abstract
The kinetics of the unimolecular decomposition of the stabilized Criegee intermediate syn-CH3CHOO has been investigated at temperatures between 297 and 331 K and pressures between 12 and 300 Torr using laser flash photolysis of CH3CHI2/O2/N2 gas mixtures coupled with time-resolved broadband UV absorption spectroscopy. Fits to experimental results using the Master Equation Solver for Multi-Energy well Reactions (MESMER) indicate that the barrier height to decomposition is 67.2 ± 1.3 kJ mol-1 and that there is a strong tunneling component to the decomposition reaction under atmospheric conditions. At 298 K and 760 Torr, MESMER simulations indicate a rate coefficient of 150-81+176 s-1 when tunneling effects are included but only 5-2+3 s-1 when tunneling is not considered in the model. MESMER simulations were also performed for the unimolecular isomerization of the stabilized Criegee intermediate anti-CH3CHOO to methyldioxirane, indicating a rate coefficient of 54-21+34 s-1 at 298 K and 760 Torr, which is not impacted by tunneling effects. Expressions to describe the unimolecular kinetics of syn- and anti-CH3CHOO are provided for use in atmospheric models, and atmospheric implications are discussed.
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Affiliation(s)
- Callum Robinson
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Lavinia Onel
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - James Newman
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Rachel Lade
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Kendrew Au
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Leonid Sheps
- Combustion
Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
| | - Dwayne E. Heard
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Paul W. Seakins
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Mark A. Blitz
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
- National
Centre for Atmospheric Science, School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Daniel Stone
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
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8
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Yang JN, Takahashi K, Lin JJM. Reaction Kinetics of Criegee Intermediates with Nitric Acid. J Phys Chem A 2022; 126:6160-6170. [PMID: 36044562 DOI: 10.1021/acs.jpca.2c04596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work investigated the reaction kinetics of HNO3 with four Criegee intermediates (CIs): CH2OO, (CH3)2COO, methyl vinyl ketone oxide (MVKO), and methacrolein oxide (MACRO). Our results show that these reactions are extremely fast with rate coefficients of (1.51 ± 0.45) × 10-10, (3.54 ± 1.06) × 10-10, (3.93 ± 1.18) × 10-10, and (3.0 ± 1.0) × 10-10 cm3 s-1 for reactions of HNO3 with CH2OO, (CH3)2COO, syn-MVKO, and anti-MACRO, respectively. This is consistent with previous results for the reactions between CIs and carboxylic acids, but the rate coefficient of CH2OO + HNO3 in the literature [Foreman Angew. Chem. 2016, 128, 10575] was found to be overestimated by a factor of 3.6. In addition, we did not observe any significant pressure dependence in the HNO3 reactions with CH2OO and (CH3)2COO under 100-400 Torr. Our results indicate that in a dry area with severe NOx pollution, the reactions of CIs with HNO3 and their products may be worthy of attention, but these reactions may be insignificant under high-humidity conditions. However, CI reactions with HNO3 may not play an important role in the atmospheric removal processes of HNO3 because of the low concentrations of CIs.
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Affiliation(s)
- Jie-Ning Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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9
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Gómez Martín JC, Lewis TR, James AD, Saiz-Lopez A, Plane JMC. Insights into the Chemistry of Iodine New Particle Formation: The Role of Iodine Oxides and the Source of Iodic Acid. J Am Chem Soc 2022; 144:9240-9253. [PMID: 35604404 PMCID: PMC9164234 DOI: 10.1021/jacs.1c12957] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
Iodine chemistry
is an important driver of new particle formation
in the marine and polar boundary layers. There are, however, conflicting
views about how iodine gas-to-particle conversion proceeds. Laboratory
studies indicate that the photooxidation of iodine produces iodine
oxides (IxOy), which are well-known particle precursors. By contrast, nitrate
anion chemical ionization mass spectrometry (CIMS) observations in
field and environmental chamber studies have been interpreted as evidence
of a dominant role of iodic acid (HIO3) in iodine-driven
particle formation. Here, we report flow tube laboratory experiments
that solve these discrepancies by showing that both IxOy and HIO3 are involved in atmospheric new particle formation. I2Oy molecules (y = 2,
3, and 4) react with nitrate core ions to generate mass spectra similar
to those obtained by CIMS, including the iodate anion. Iodine pentoxide
(I2O5) produced by photolysis of higher-order
IxOy is hydrolyzed,
likely by the water dimer, to yield HIO3, which also contributes
to the iodate anion signal. We estimate that ∼50% of the iodate
anion signals observed by nitrate CIMS under atmospheric water vapor
concentrations originate from I2Oy. Under such conditions, iodine-containing clusters and particles
are formed by aggregation of I2Oy and HIO3, while under dry laboratory conditions,
particle formation is driven exclusively by I2Oy. An updated mechanism for iodine gas-to-particle
conversion is provided. Furthermore, we propose that a key iodine
reservoir species such as iodine nitrate, which we observe as a product
of the reaction between iodine oxides and the nitrate anion, can also
be detected by CIMS in the atmosphere.
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Affiliation(s)
| | - Thomas R Lewis
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Serrano 119, Madrid 28006, Spain.,School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | | | - Alfonso Saiz-Lopez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, CSIC, Serrano 119, Madrid 28006, Spain
| | - John M C Plane
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
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10
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Lin YH, Takahashi K, Lin JJM. Absolute photodissociation cross sections of thermalized methyl vinyl ketone oxide and methacrolein oxide. Phys Chem Chem Phys 2022; 24:10439-10450. [PMID: 35441630 DOI: 10.1039/d2cp00476c] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methyl vinyl ketone oxide (MVKO) and methacrolein oxide (MACRO) are resonance-stabilized Criegee intermediates which are formed in the ozonolysis reaction of isoprene, the most abundant unsaturated hydrocarbon in the atmosphere. The absolute photodissociation cross sections of MVKO and MACRO were determined by measuring their laser depletion fraction at 352 nm, which was deduced from their time-resolved UV-visible absorption spectra. After calibrating the 352 nm laser fluence with the photodissociation of NO2, for which the absorption cross section and photodissociation quantum yield are well known, the photodissociation cross sections of thermalized (299 K) MVKO and MACRO at 352 nm were determined to be (3.02 ± 0.60) × 10-17 cm2 and (1.53 ± 0.29) × 10-17 cm2, respectively. Using their reported spectra and photodissociation quantum yields, their peak absorption cross sections were deduced to be (3.70 ± 0.74) × 10-17 cm2 (at 371 nm, MVKO) and (3.04 ± 0.58) × 10-17 cm2 (at 397 nm, MACRO). These values agree fairly with our theoretical predictions and are substantially larger than those of smaller, alkyl-substituted Criegee intermediates (CH2OO, syn-CH3CHOO, (CH3)2COO), revealing the effect of extended conjugation. With their cross sections, we also quantified the synthesis yields of MVKO and MACRO in the present experiment to be 0.22 ± 0.10 (at 299 K and 30-700 torr) and 0.043 ± 0.019 (at 299 K and 500 torr), respectively, relative to their photolyzed precursors. The lower yield of MACRO can be related to the high endothermicity of its formation channel.
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Affiliation(s)
- Yen-Hsiu Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan. .,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan. .,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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11
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Koenig TK, Volkamer R, Apel EC, Bresch JF, Cuevas CA, Dix B, Eloranta EW, Fernandez RP, Hall SR, Hornbrook RS, Pierce RB, Reeves JM, Saiz-Lopez A, Ullmann K. Ozone depletion due to dust release of iodine in the free troposphere. SCIENCE ADVANCES 2021; 7:eabj6544. [PMID: 34936464 PMCID: PMC8694599 DOI: 10.1126/sciadv.abj6544] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/03/2021] [Indexed: 06/03/2023]
Abstract
Iodine is an atmospheric trace element emitted from oceans that efficiently destroys ozone (O3). Low O3 in airborne dust layers is frequently observed but poorly understood. We show that dust is a source of gas-phase iodine, indicated by aircraft observations of iodine monoxide (IO) radicals inside lofted dust layers from the Atacama and Sechura Deserts that are up to a factor of 10 enhanced over background. Gas-phase iodine photochemistry, commensurate with observed IO, is needed to explain the low O3 inside these dust layers (below 15 ppbv; up to 75% depleted). The added dust iodine can explain decreases in O3 of 8% regionally and affects surface air quality. Our data suggest that iodate reduction to form volatile iodine species is a missing process in the geochemical iodine cycle and presents an unrecognized aeolian source of iodine. Atmospheric iodine has tripled since 1950 and affects ozone layer recovery and particle formation.
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Affiliation(s)
- Theodore K. Koenig
- Department of Chemistry, University of Colorado Boulder, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, CO, USA
| | - Rainer Volkamer
- Department of Chemistry, University of Colorado Boulder, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, CO, USA
| | - Eric C. Apel
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - James F. Bresch
- Mesoscale & Microscale Meteorology Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Carlos A. Cuevas
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Spanish National Research Council (CSIC), Madrid, Spain
| | - Barbara Dix
- Department of Chemistry, University of Colorado Boulder, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, Boulder, CO, USA
| | - Edwin W. Eloranta
- Space Science and Engineering Center, University of Wisconsin, Madison, WI, USA
| | - Rafael P. Fernandez
- Institute for Interdisciplinary Science, National Research Council (ICB-CONICET), FCEN-UNCuyo, Mendoza, Argentina
| | - Samuel R. Hall
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Rebecca S. Hornbrook
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - R. Bradley Pierce
- The National Environmental Satellite, Data, and Information Service (NESDIS), Madison, WI, USA
| | - J. Michael Reeves
- Earth Observing Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Alfonso Saiz-Lopez
- Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Spanish National Research Council (CSIC), Madrid, Spain
| | - Kirk Ullmann
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
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12
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Cornwell ZA, Harrison AW, Murray C. Kinetics of the Reactions of CH 2OO with Acetone, α-Diketones, and β-Diketones. J Phys Chem A 2021; 125:8557-8571. [PMID: 34554761 DOI: 10.1021/acs.jpca.1c05280] [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
Rate constants for the reactions between the simplest Criegee intermediate, CH2OO, with acetone, the α-diketones biacetyl and acetylpropionyl, and the β-diketones acetylacetone and 3,3-dimethyl-2,4-pentanedione have been measured at 295 K. CH2OO was produced photochemically in a flow reactor by 355 nm laser flash photolysis of diiodomethane in the presence of excess oxygen. Time-dependent concentrations were measured using broadband transient absorption spectroscopy, and the reaction kinetics was characterized under pseudo-first-order conditions. The bimolecular rate constant for the CH2OO + acetone reaction is measured to be (4.1 ± 0.4) × 10-13 cm3 s-1, consistent with previous measurements. The reactions of CH2OO with the β-diketones acetylacetone and 3,3-dimethyl-2,5-pentanedione are found to have broadly similar rate constants of (6.6 ± 0.7) × 10-13 and (3.5 ± 0.8) × 10-13 cm3 s-1, respectively; these values may be cautiously considered as upper limits. In contrast, α-diketones react significantly faster, with rate constants of (1.45 ± 0.18) × 10-11 and (1.29 ± 0.15) × 10-11 cm3 s-1 measured for biacetyl and acetylpropionyl. The potential energy surfaces for these 1,3-dipolar cycloaddition reactions are characterized at the M06-2X/aug-cc-pVTZ and CBS-QB3 levels of theory and provide additional support to the observed experimental trends. The reactivity of carbonyl compounds with CH2OO is also interpreted by application of frontier molecular orbital theory and predicted using Hammett substituent constants. Finally, the results are compared with other kinetic studies of Criegee intermediate reactions with carbonyl compounds and discussed within the context of their atmospheric relevance.
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Affiliation(s)
- Zachary A Cornwell
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Aaron W Harrison
- Department of Chemistry, Austin College, Sherman, Texas 75090, United States
| | - Craig Murray
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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13
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Onel L, Lade R, Mortiboy J, Blitz MA, Seakins PW, Heard DE, Stone D. Kinetics of the gas phase reaction of the Criegee intermediate CH 2OO with SO 2 as a function of temperature. Phys Chem Chem Phys 2021; 23:19415-19423. [PMID: 34494054 DOI: 10.1039/d1cp02932k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The kinetics of the gas phase reaction of the Criegee intermediate CH2OO with SO2 have been studied as a function of temperature in the range 223-344 K at 85 Torr using flash photolysis of CH2I2/O2/SO2/N2 mixtures at 248 nm coupled to time-resolved broadband UV absorption spectroscopy. Measurements were performed under pseudo-first-order conditions with respect to SO2, revealing a negative temperature dependence. Analysis of experimental results using the Master Equation Solver for Multi-Energy well Reactions (MESMER) indicates that the observed temperature dependence, combined with the reported lack of a pressure dependence in the range 1.5-760 Torr, can be described by a reaction mechanism consisting of the formation of a pre-reaction complex leading to a cyclic secondary ozonide which subsequently decomposes to produce HCHO + SO3. The temperature dependence can be characterised by kCH2OO+SO2 = (3.72 ± 0.13) × 10-11 (T/298)(-2.05±0.38) cm3 molecule-1 s-1. The observed negative temperature dependence for the title reaction in conjunction with the decrease in water dimer (the main competitor for the Criegee intermediate) concentration at lower temperatures means that Criegee intermediate chemistry can play an enhanced role in SO2 oxidation in the atmosphere at lower temperatures.
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Affiliation(s)
- Lavinia Onel
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Rachel Lade
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | | | - Mark A Blitz
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK. .,National Centre for Atmospheric Science, University of Leeds, Leeds, LS2 9JT, UK
| | - Paul W Seakins
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Dwayne E Heard
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Daniel Stone
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
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14
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Lin Y, Lin JJ. A new approach to determine the absolute photodissociation cross section of molecules in a cell. J CHIN CHEM SOC-TAIP 2021. [DOI: 10.1002/jccs.202100336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yen‐Hsiu Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei Taiwan
| | - Jim Jr‐Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei Taiwan
- Department of Chemistry National Taiwan University Taipei Taiwan
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15
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Kuo MT, Yang JN, Lin JJM, Takahashi K. Substituent Effect in the Reactions between Criegee Intermediates and 3-Aminopropanol. J Phys Chem A 2021; 125:6580-6590. [PMID: 34314585 DOI: 10.1021/acs.jpca.1c03737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Via intramolecular H atom transfer, 3-aminopropanol is more reactive toward Criegee intermediates, in comparison with amines or alcohols. Here we accessed the substituent effect of Criegee intermediates in their reactions with 3-aminopropanol. Through real-time monitoring the concentrations of two Criegee intermediates with their strong UV absorption at 340 nm, the experimental rate coefficients at 298 K (100-300 Torr) were determined to be (1.52 ± 0.08) × 10-11 and (1.44 ± 0.22) × 10-13 cm3 s-1 for the reactions of 3-aminopropanol with (CH3)2COO (acetone oxide) and CH2CHC(CH3)OO (methyl vinyl ketone oxide), respectively. Compared to our previous experimental value for the reaction with syn-CH3CHOO, (1.24 ± 0.13) × 10-11 cm3 s-1, we can see that the methyl substitution at the anti position has little effect on the reactivity while the vinyl substitution causes a drastic decrease in the reactivity. Our theoretical calculations based on CCSD(T)-F12 energies reproduce this 2-order-of-magnitude decrease in the rate coefficient caused by the vinyl substitution. Using the activation strain model, we found that the interaction of Criegee intermediates with 3-aminopropanol is weaker for the case of vinyl substitution. This effect can be further rationalized by the delocalization of the lowest unoccupied molecular orbital for the vinyl-substituted Criegee intermediates. These results would help us better estimate the impact of similar reactions like the reactions of Criegee intermediates with water vapor, some of which could be difficult to measure experimentally but can be important in the atmosphere. We also found that the B2PLYP-D3BJ/aug-cc-pVTZ calculation can reproduce the CCSD(T)-F12 reaction barrier energies within ca. 1 kcal mol-1, indicating that the use of the B2PLYP-D3BJ method is promising for future predictions of the reactions of larger Criegee intermediates.
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Affiliation(s)
- Mei-Tsan Kuo
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Jie-Ning Yang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.,Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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16
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Surprisingly long lifetime of methacrolein oxide, an isoprene derived Criegee intermediate, under humid conditions. Commun Chem 2021; 4:12. [PMID: 36697547 PMCID: PMC9814537 DOI: 10.1038/s42004-021-00451-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023] Open
Abstract
Ozonolysis of isoprene, the most abundant alkene, produces three distinct Criegee intermediates (CIs): CH2OO, methyl vinyl ketone oxide (MVKO) and methacrolein oxide (MACRO). The oxidation of SO2 by CIs is a potential source of H2SO4, an important precursor of aerosols. Here we investigated the UV-visible spectroscopy and reaction kinetics of thermalized MACRO. An extremely fast reaction of anti-MACRO with SO2 has been found, kSO2 = (1.5 ± 0.4) × 10-10 cm3 s-1 (±1σ, σ is the standard deviation of the data) at 298 K (150 - 500 Torr), which is ca. 4 times the value for syn-MVKO. However, the reaction of anti-MACRO with water vapor has been observed to be quite slow with an effective rate coefficient of (9 ± 5) × 10-17 cm3 s-1 (±1σ) at 298 K (300 to 500 Torr), which is smaller than current literature values by 1 or 2 orders of magnitude. Our results indicate that anti-MACRO has an atmospheric lifetime (best estimate ca. 18 ms at 298 K and RH = 70%) much longer than previously thought (ca. 0.3 or 3 ms), resulting in a much higher steady-state concentration. Owing to larger reaction rate coefficient, the impact of anti-MACRO on the oxidation of atmospheric SO2 would be substantial, even more than that of syn-MVKO.
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17
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Onel L, Blitz M, Seakins P, Heard D, Stone D. Kinetics of the Gas Phase Reactions of the Criegee Intermediate CH 2OO with O 3 and IO. J Phys Chem A 2020; 124:6287-6293. [PMID: 32667796 DOI: 10.1021/acs.jpca.0c04422] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The kinetics of the gas phase reactions of the Criegee intermediate CH2OO with O3 and IO have been studied at 296 K and 300 Torr through simultaneous measurements of CH2OO, the CH2OO precursor (CH2I2), O3, and IO using flash photolysis of CH2I2/O2/O3/N2 mixtures at 248 nm coupled to time-resolved broadband UV absorption spectroscopy. Experiments were performed under pseudo-first-order conditions with respect to O3, with the rate coefficients for reactions of CH2OO with O3 and IO obtained by fitting to the observed decays of CH2OO using a model constrained to the measured concentrations of IO. Fits were performed globally, with the ratio between the initial concentration of O3 and the average concentration of IO varying in the range 30-700, and gave kCH2OO+O3 = (3.6 ± 0.8) × 10-13 cm3 molecule-1 s-1 and kCH2OO+IO = (7.6 ± 1.4) × 10-11 cm3 molecule-1 s-1 (where the errors are at the 2σ level). The magnitude of kCH2OO+O3 has a significant effect on the steady state concentration of CH2OO in chamber studies. Atmospheric implications of the results are discussed.
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18
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Direct kinetic measurements and theoretical predictions of an isoprene-derived Criegee intermediate. Proc Natl Acad Sci U S A 2020; 117:9733-9740. [PMID: 32321826 DOI: 10.1073/pnas.1916711117] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Isoprene has the highest emission into Earth's atmosphere of any nonmethane hydrocarbon. Atmospheric processing of alkenes, including isoprene, via ozonolysis leads to the formation of zwitterionic reactive intermediates, known as Criegee intermediates (CIs). Direct studies have revealed that reactions involving simple CIs can significantly impact the tropospheric oxidizing capacity, enhance particulate formation, and degrade local air quality. Methyl vinyl ketone oxide (MVK-oxide) is a four-carbon, asymmetric, resonance-stabilized CI, produced with 21 to 23% yield from isoprene ozonolysis, yet its reactivity has not been directly studied. We present direct kinetic measurements of MVK-oxide reactions with key atmospheric species using absorption spectroscopy. Direct UV-Vis absorption spectra from two independent flow cell experiments overlap with the molecular beam UV-Vis-depletion spectra reported recently [M. F. Vansco, B. Marchetti, M. I. Lester, J. Chem. Phys. 149, 44309 (2018)] but suggest different conformer distributions under jet-cooled and thermal conditions. Comparison of the experimental lifetime herein with theory indicates only the syn-conformers are observed; anti-conformers are calculated to be removed much more rapidly via unimolecular decay. We observe experimentally and predict theoretically fast reaction of syn-MVK-oxide with SO2 and formic acid, similar to smaller alkyl-substituted CIs, and by contrast, slow removal in the presence of water. We determine products through complementary multiplexed photoionization mass spectrometry, observing SO3 and identifying organic hydroperoxide formation from reaction with SO2 and formic acid, respectively. The tropospheric implications of these reactions are evaluated using a global chemistry and transport model.
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19
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Lin YH, Li YL, Chao W, Takahashi K, Lin JJM. The role of the iodine-atom adduct in the synthesis and kinetics of methyl vinyl ketone oxide—a resonance-stabilized Criegee intermediate. Phys Chem Chem Phys 2020; 22:13603-13612. [DOI: 10.1039/d0cp02085k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The adduct decomposition is the major pathway that forms CH3(C2H3)COO (MVKO) + I via the reaction of CH3(C2H3)CI + O2 for P > 50 Torr. The related kinetics of the adduct and MVKO + SO2 reactions have been studied over 4–700 Torr and 278–319 K.
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Affiliation(s)
- Yen-Hsiu Lin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
- Department of Chemistry
| | - Yu-Lin Li
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
- Department of Chemistry
| | - Wen Chao
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
- Department of Chemistry
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20
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Chao W, Yin C, Takahashi K, Lin JJM. Effects of water vapor on the reaction of CH2OO with NH3. Phys Chem Chem Phys 2019; 21:22589-22597. [DOI: 10.1039/c9cp04682h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A strong synergic effect of water and ammonia molecules may enhance the formation of H2NCH2OOH.
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Affiliation(s)
- Wen Chao
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Cangtao Yin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
| | - Jim Jr-Min Lin
- Institute of Atomic and Molecular Sciences
- Academia Sinica
- Taipei 10617
- Taiwan
- Department of Chemistry
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21
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Tadayon SV, Foreman ES, Murray C. Kinetics of the Reactions between the Criegee Intermediate CH2OO and Alcohols. J Phys Chem A 2017; 122:258-268. [DOI: 10.1021/acs.jpca.7b09773] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sara V. Tadayon
- Department of Chemistry, University of California, Irvine, Irvine California 92697, United States
| | - Elizabeth S. Foreman
- Department of Chemistry, University of California, Irvine, Irvine California 92697, United States
| | - Craig Murray
- Department of Chemistry, University of California, Irvine, Irvine California 92697, United States
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22
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Foreman ES, Kapnas KM, Murray C. Reactions between Criegee Intermediates and the Inorganic Acids HCl and HNO3: Kinetics and Atmospheric Implications. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604662] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Kara M. Kapnas
- Department of Chemistry; University of California, Irvine; Irvine CA 92697 USA
| | - Craig Murray
- Department of Chemistry; University of California, Irvine; Irvine CA 92697 USA
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23
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Foreman ES, Kapnas KM, Murray C. Reactions between Criegee Intermediates and the Inorganic Acids HCl and HNO3: Kinetics and Atmospheric Implications. Angew Chem Int Ed Engl 2016; 55:10419-22. [DOI: 10.1002/anie.201604662] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/01/2016] [Indexed: 11/06/2022]
Affiliation(s)
| | - Kara M. Kapnas
- Department of Chemistry; University of California, Irvine; Irvine CA 92697 USA
| | - Craig Murray
- Department of Chemistry; University of California, Irvine; Irvine CA 92697 USA
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24
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Foreman ES, Murray C. Kinetics of IO Production in the CH2I + O2 Reaction Studied by Cavity Ring-Down Spectroscopy. J Phys Chem A 2015; 119:8981-90. [DOI: 10.1021/acs.jpca.5b05058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Elizabeth S. Foreman
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Craig Murray
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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25
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Foreman ES, Kapnas KM, Jou Y, Kalinowski J, Feng D, Gerber RB, Murray C. High resolution absolute absorption cross sections of the B̃1A′–X̃1A′ transition of the CH2OO biradical. Phys Chem Chem Phys 2015; 17:32539-46. [DOI: 10.1039/c5cp04977f] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbonyl oxides, or Criegee intermediates, are formed from the gas phase ozonolysis of alkenes and play a pivotal role in night-time and urban area atmospheric chemistry.
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Affiliation(s)
| | - Kara M. Kapnas
- Department of Chemistry
- University of California
- Irvine, USA
| | - YiTien Jou
- Department of Chemistry
- University of California
- Irvine, USA
| | | | - David Feng
- Department of Mechanical and Aerospace Engineering
- University of California
- Irvine, USA
| | - R. Benny Gerber
- Department of Chemistry
- University of California
- Irvine, USA
- Department of Chemistry
- University of Helsinki
| | - Craig Murray
- Department of Chemistry
- University of California
- Irvine, USA
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26
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Monahan C, Ashu-Ayem ER, Nitschke U, Darby SB, Smith PD, Stengel DB, Venables DS, O'Dowd CD. Coastal iodine emissions: part 2. Chamber experiments of particle formation from Laminaria digitata-derived and laboratory-generated I₂. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:10422-8. [PMID: 22934718 DOI: 10.1021/es3011805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Laboratory studies into particle formation from Laminaria digitata macroalgae were undertaken to elucidate aerosol formation for a range of I(2) (0.3-76 ppb(v)) and O(3) (<3-96 ppb(v)) mixing ratios and light levels (E(PAR) = 15, 100, and 235 μmol photons m(-2) s(-1)). No clear pattern was observed for I(2) or aerosol parameters as a function of light levels. Aerosol mass fluxes and particle number concentrations, were, however, correlated with I(2) mixing ratios for low O(3) mixing ratios of <3 ppb(v) (R(2) = 0.7 and 0.83, respectively for low light levels, and R(2) = 0.95 and 0.98, respectively for medium light levels). Additional experiments into particle production as a function of laboratory-generated I(2), over a mixing ratio range of 1-8 ppb(v), were conducted under moderate O(3) mixing ratios (∼24 ppb(v)) where a clear, 100-fold or greater, increase in the aerosol number concentrations and mass fluxes was observed compared to the low O(3) experiments. A linear relationship between particle concentration and I(2) was found, in reasonable agreement with previous studies. Scaling the laboratory relationship to aerosol concentrations typical of the coastal boundary layer suggests a I(2) mixing ratio range of 6-93 ppt(v) can account for the observed particle production events. Aerosol number concentration produced from I(2) is more than a factor of 10 higher than that produced from CH(2)I(2) for the same mixing ratios.
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Affiliation(s)
- Ciaran Monahan
- School of Physics and Centre for Climate & Air Pollution Studies, Ryan Institute, National University of Ireland Galway, University Road, Galway, Ireland
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27
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Ashu-Ayem ER, Nitschke U, Monahan C, Chen J, Darby SB, Smith PD, O'Dowd CD, Stengel DB, Venables DS. Coastal iodine emissions. 1. Release of I₂ by Laminaria digitata in chamber experiments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:10413-21. [PMID: 22934673 DOI: 10.1021/es204534v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Tidally exposed macroalgae emit large amounts of I(2) and iodocarbons that produce hotspots of iodine chemistry and intense particle nucleation events in the coastal marine boundary layer. Current emission rates are poorly characterized, however, with reported emission rates varying by 3 orders of magnitude. In this study, I(2) emissions from 25 Laminaria digitata samples were investigated in a simulation chamber using incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). The chamber design allowed gradual extraction of seawater to simulate tidal emersion of algae. Samples were exposed to air with or without O(3) and to varying irradiances. Emission of I(2) occurred in four distinct stages: (1) moderate emissions from partially submerged samples; (2) a strong release by fully emerged samples; (3) slowing or stopping of I(2) release; and (4) later pulses of I(2) evident in some samples. Emission rates were highly variable and ranged from 7 to 616 pmol min(-1) gFW(-1) in ozone-free air, with a median value of 55 pmol min(-1) gFW(-1) for 20 samples.
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Affiliation(s)
- Enowmbi R Ashu-Ayem
- Department of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland
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28
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Saiz-Lopez A, Plane JMC, Baker AR, Carpenter LJ, von Glasow R, Gómez Martín JC, McFiggans G, Saunders RW. Atmospheric Chemistry of Iodine. Chem Rev 2011; 112:1773-804. [DOI: 10.1021/cr200029u] [Citation(s) in RCA: 383] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Alfonso Saiz-Lopez
- Laboratory for Atmospheric and Climate Science (CIAC), CSIC, Toledo, Spain
| | - John M. C. Plane
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Alex R. Baker
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Lucy J. Carpenter
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Roland von Glasow
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | | | - Gordon McFiggans
- School of Earth, Atmospheric & Environmental Sciences, University of Manchester, Manchester, M13 9PL, United Kingdom
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29
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Gravestock TJ, Blitz MA, Heard DE. A laser induced fluorescence study relating to physical properties of the iodine monoxide radical. Phys Chem Chem Phys 2010; 12:823-34. [DOI: 10.1039/b910571a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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30
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Sakamoto Y, Yabushita A, Kawasaki M, Enami S. Direct Emission of I2 Molecule and IO Radical from the Heterogeneous Reactions of Gaseous Ozone with Aqueous Potassium Iodide Solution. J Phys Chem A 2009; 113:7707-13. [DOI: 10.1021/jp903486u] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Yosuke Sakamoto
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Akihiro Yabushita
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Masahiro Kawasaki
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Shinichi Enami
- W. M. Keck Laboratories, California Institute of Technology, Pasadena, California 91125
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31
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Gómez Martín JC, Plane JM. Determination of the O–IO bond dissociation energy by photofragment excitation spectroscopy. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.04.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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32
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Enami S, Sakamoto Y, Yamanaka T, Hashimoto S, Kawasaki M, Tonokura K, Tachikawa H. Reaction Mechanisms of IO Radical Formation from the Reaction of CH3I with Cl Atom in the Presence of O2. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2008. [DOI: 10.1246/bcsj.81.1250] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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33
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Ion imaging study of IO radical photodissociation: Accurate bond dissociation energy determination. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.04.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Dillon TJ, Tucceri ME, Sander R, Crowley JN. LIF studies of iodine oxide chemistry : Part 3. Reactions IO + NO3 → OIO + NO2, I + NO3 → IO + NO2, and CH2I + O2 → (products): implications for the chemistry of the marine atmosphere at night. Phys Chem Chem Phys 2008; 10:1540-54. [DOI: 10.1039/b717386e] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Vaughan S, Gherman T, Ruth AA, Orphal J. Incoherent broad-band cavity-enhanced absorption spectroscopy of the marine boundary layer species I2, IO and OIO. Phys Chem Chem Phys 2008; 10:4471-7. [PMID: 18654688 DOI: 10.1039/b802618a] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Stewart Vaughan
- Department of Physics, University College Cork, Cork, Ireland
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Formation of the iodine monoxide radical from gas-phase reactions of iodoalkyl radicals with molecular oxygen. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.08.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Saiz-Lopez A, Mahajan AS, Salmon RA, Bauguitte SJB, Jones AE, Roscoe HK, Plane JMC. Boundary Layer Halogens in Coastal Antarctica. Science 2007; 317:348-51. [PMID: 17641195 DOI: 10.1126/science.1141408] [Citation(s) in RCA: 250] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Halogens influence the oxidizing capacity of Earth's troposphere, and iodine oxides form ultrafine aerosols, which may have an impact on climate. We report year-round measurements of boundary layer iodine oxide and bromine oxide at the near-coastal site of Halley Station, Antarctica. Surprisingly, both species are present throughout the sunlit period and exhibit similar seasonal cycles and concentrations. The springtime peak of iodine oxide (20 parts per trillion) is the highest concentration recorded anywhere in the atmosphere. These levels of halogens cause substantial ozone depletion, as well as the rapid oxidation of dimethyl sulfide and mercury in the Antarctic boundary layer.
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Enami S, Hoshino Y, Kawasaki M. A kinetic study of the gas-phase reactions of OIO with NO, NO2, and Cl2. INT J CHEM KINET 2007. [DOI: 10.1002/kin.20283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Martín JCG, Spietz P, Burrows JP. Kinetic and Mechanistic Studies of the I2/O3 Photochemistry. J Phys Chem A 2006; 111:306-20. [PMID: 17214469 DOI: 10.1021/jp061186c] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The atmospherically relevant chemistry generated by photolysis of I2/O3 mixtures has been studied at 298 K in the pressure range from 10 to 400 hPa by using a laboratory flash photolysis setup combining atomic resonance and molecular absorption spectroscopy. The temporal behaviors of I, I(2), IO, and OIO have been retrieved. Conventional kinetic methods and numerical modeling have been applied to investigate the IO self-reaction and the secondary chemistry. A pressure independent value of k(IO + IO) = (7.6 +/- 1.1) x 10(-11) cm(3) molecule-1 s(-1) has been determined. The pressure dependence of the branching ratios for the I + OIO and IOIO product channels in the IO + IO reaction have been determined and have values of 0.45 +/- 0.10 and 0.44 +/- 0.13 at 400 hPa, respectively. The branching ratios for the 2I + O(2) and I(2) + O(2) product channels are pressure independent with values of 0.09 +/- 0.06 and 0.05 +/- 0.03, respectively. The sensitivity analysis indicates that the isomer IOIO is more thermally stable than predicted by theoretical calculations. A reaction scheme comprising OIO polymerization steps has been shown to be consistent with the temporal behaviors recorded in this study. For simplicity, the rate coefficient has been assumed to be the same for each reaction (OIO)(n) + IO --> (OIO)(n+1), n = 1, 2, 3, 4. The lower limit obtained for this rate coefficient is (1.2 +/- 0.3) x 10(-10) cm(3) molecule(-1) s(-1) at 400 hPa. Evidence for the participation of IO in the polymerization mechanism also has been found. The rate coefficient for IO attachment to OIO and to small polymers has been determined to be larger than (5 +/- 2) x 10(-11) cm(3) molecule(-1) s(-1) at 400 hPa. These results provide supporting evidence for atmospheric particle formation induced by polymerization of iodine oxides.
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Affiliation(s)
- Juan Carlos Gómez Martín
- Institute of Environmental Physics, University of Bremen, P. O. Box 330440, 28334 Bremen, Germany
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Enami S, Yamanaka T, Hashimoto S, Kawasaki M, Nakano Y, Ishiwata T. Kinetic Study of IO Radical with RO2 (R = CH3, C2H5, and CF3) Using Cavity Ring-Down Spectroscopy. J Phys Chem A 2006; 110:9861-6. [PMID: 16898687 DOI: 10.1021/jp0619336] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reactions of iodine monoxide radical, IO, with alkyl peroxide radicals, RO(2) (R = CH(3), C(2)H(5), and CF(3)), have been studied using cavity ring-down spectroscopy. The rate constant of the reaction of IO with CH(3)O(2) was determined to be (7.0 +/- 3.0) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K and 100 Torr of N(2) diluent. The quoted uncertainty is two standard deviations. No significant pressure dependence of the rate constant was observed at 30-130 Torr total pressure of N(2) diluent. The temperature dependence of the rate constants was also studied at 213-298 K. The upper limit of the branching ratio of OIO radical formation from IO + CH(3)O(2) was estimated to be <0.1. The reaction rate constants of IO + C(2)H(5)O(2) and IO + CF(3)O(2) were determined to be (14 +/- 6) x 10(-11) and (6.3 +/- 2.7) x 10(-11) cm(3) molecule(-1) s(-1) at 298 K, 100 Torr of N(2) diluent, respectively. The upper limit of the reaction rate constant of IO with CH(3)I was <4 x 10(-14) cm(3) molecule(-1) s(-1).
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Affiliation(s)
- Shinichi Enami
- Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan
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