1
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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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2
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Nikoobakht B. 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 2023; 127:10091-10103. [PMID: 38012831 DOI: 10.1021/acs.jpca.3c05323] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
An extended theoretical analysis of the photodissociation dynamics of the four-carbon Criegee intermediate (CH2═CH(CH3)COO) or methyl vinyl ketone oxide, which has four conformers, following excitation to the B state, is presented. Our analysis relies on multireference electronic wave functions combined with a wavepacket propagation treatment for the two coupled B1A' and C1A' electronic states and two nuclear degrees of freedom. For each conformer, the 2D model depends on potential energy surfaces (PESs) along the O-O and C-O-O bending modes for the two lowest excited states, B1A' and C1A', and is sufficiently accurate to reproduce the experimental B1A' ← X1A' absorption spectrum with unprecedented accuracy. It is found that the roles of each conformer are essential in producing a cumulative spectrum, which is close to the recent experimental spectrum. The anti-trans and anti-cis conformers make contributions at the longer and shorter wavelengths of the cumulative spectrum, respectively, while the syn-cis and syn-trans conformers have contributions in the middle wavelength range of the cumulative spectrum of MVK-oxide. The existence of a deep well for each conformer on the PESs of the (diabatic) B state causes a considerable amount of the wavepacket to be reflected by the B state wells, which can explain the oscillatory structures appearing in the long wavelength range of 360-480 nm of the spectrum. The weakly avoided crossings between the B-state and C-state PESs of each conformer appearing within the range of 2.80-3.08 eV excitation energy cause considerable disturbance in the vibronic fine structure of the bands. The results give novel insight into the complex interactions governing this intriguing process.
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Affiliation(s)
- Behnam Nikoobakht
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, INF 229, D-69120 Heidelberg, Germany
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3
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Poirier CA, Guidry LM, Ratliff JM, Esposito VJ, Marchetti B, Karsili TNV. Modeling the Ground- and Excited-State Unimolecular Decay of the Simplest Fluorinated Criegee Intermediate, HFCOO, Formed from the Ozonolysis of Hydrofluoroolefin Refrigerants. J Phys Chem A 2023; 127:6377-6384. [PMID: 37523496 DOI: 10.1021/acs.jpca.3c01530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Hydrofluoroolefins (HFO) are fourth-generation refrigerants designed to function as efficient refrigerants with no ozone depletion potential and zero global warming potential. Despite extensive studies on their chemical and physical properties, the ground- and excited-state chemistry of their atmospheric oxidation products is less well understood. This study focuses on the ground- and excited-state chemistry of the simplest fluorinated Criegee intermediate (CI), fluoroformaldehyde oxide (HFCOO), which is the simplest fluorinated CI formed from the ozonolysis of HFOs. HFCOO contains syn- and anti-conformers, which have Boltzmann populations of, respectively, 87 and 13% at 298 K. For both conformers, the calculated ground-state reaction energy profiles associated with cyclization to form fluorodioxirane is lower than the equivalent unimolecular decay path in the simplest CI, H2COO, with anti-HFCOO returning a barrier height more than half of that of H2COO. The excited-state dynamics reveal that photoexcitation to the bright S2 state of syn-HFCOO and anti-HFCOO is expected to undergo a prompt O-O fission─with the former conformer expected to dissociate with an almost unity quantum yield and to form both O (1D) + HFCO (S0) and O (3P) + HFCO (T1) products. In contrast, photoexcitation of anti-HFCOO is expected to undergo an O-O bond fission with a non-unity quantum yield. The fraction of photoexcited anti-HFCOO that dissociates is predicted to exclusively form O (1D) + HFCO (S0) products, which is in sharp contrast to H2COO. The wider implications of our results are discussed from both physical and atmospheric chemistry perspectives.
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Affiliation(s)
- Courtney A Poirier
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
- Regional Application Center, NASA/University of Louisiana at Lafayette, Lafayette, Louisiana 70506, United States
| | - Lily M Guidry
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
| | - Jordyn M Ratliff
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
| | - Vincent J Esposito
- NASA Postdoctoral Program Fellow, NASA Ames Research Center, Moffett Field, California 94035-1000, United States
| | - Barbara Marchetti
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
| | - Tolga N V Karsili
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
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4
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Wang G, Liu T, Zou M, Karsili TNV, Lester MI. UV photodissociation dynamics of the acetone oxide Criegee intermediate: experiment and theory. Phys Chem Chem Phys 2023; 25:7453-7465. [PMID: 36848133 DOI: 10.1039/d3cp00207a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The photodissociation dynamics of the dimethyl-substituted acetone oxide Criegee intermediate [(CH3)2COO] is characterized following electronic excitation to the bright 1ππ* state, which leads to O (1D) + acetone [(CH3)2CO, S0] products. The UV action spectrum of (CH3)2COO recorded with O (1D) detection under jet-cooled conditions is broad, unstructured, and essentially unchanged from the corresponding electronic absorption spectrum obtained using a UV-induced depletion method. This indicates that UV excitation of (CH3)2COO leads predominantly to the O (1D) product channel. A higher energy O (3P) + (CH3)2CO (T1) product channel is not observed, although it is energetically accessible. In addition, complementary MS-CASPT2 trajectory surface-hopping (TSH) simulations indicate minimal population leading to the O (3P) channel and non-unity overall probability for dissociation (within 100 fs). Velocity map imaging of the O (1D) products is utilized to reveal the total kinetic energy release (TKER) distribution upon photodissociation of (CH3)2COO at various UV excitation energies. Simulation of the TKER distributions is performed using a hybrid model that combines an impulsive model with a statistical component, the latter reflecting the longer-lived (>100 fs) trajectories identified in the TSH calculations. The impulsive model accounts for vibrational activation of (CH3)2CO arising from geometrical changes between the Criegee intermediate and the carbonyl product, indicating the importance of CO stretch, CCO bend, and CC stretch along with activation of hindered rotation and rock of the methyl groups in the (CH3)2CO product. Detailed comparison is also made with the TKER distribution arising from photodissociation dynamics of CH2OO upon UV excitation.
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Affiliation(s)
- Guanghan Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
| | - Tianlin Liu
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
| | - Meijun Zou
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
| | - Tolga N V Karsili
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
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5
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Karsili TNV, Marchetti B, Lester MI, Ashfold MNR. Electronic Absorption Spectroscopy and Photochemistry of Criegee Intermediates. Photochem Photobiol 2023; 99:4-18. [PMID: 35713380 DOI: 10.1111/php.13665] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/14/2022] [Indexed: 01/26/2023]
Abstract
Interest in Criegee intermediates (CIs), often termed carbonyl oxides, and their role in tropospheric chemistry has grown massively since the demonstration of laboratory-based routes to their formation and characterization in the gas phase. This article reviews current knowledge regarding the electronic spectroscopy of atmospherically relevant CIs like CH2 OO, CH3 CHOO, (CH3 )2 COO and larger CIs like methyl vinyl ketone oxide and methacrolein oxide that are formed in the ozonolysis of isoprene, and of selected conjugated carbene-derived CIs of interest in the synthetic chemistry community. Of the aforementioned atmospherically relevant CIs, all except CH2 OO and (CH3 )2 COO exist in different conformers which, under tropospheric conditions, can display strikingly different thermal loss rates via unimolecular and bimolecular processes. Calculated photolysis rates based on their absorption properties suggest that solar photolysis will rarely be a significant contributor to the total loss rate for any CI under tropospheric conditions. Nonetheless, there is ever-growing interest in the absorption cross sections and primary photochemistry of CIs following excitation to the strongly absorbing 1 ππ* state, and how this varies with CI, with conformer and with excitation wavelength. The later part of this review surveys the photochemical data reported to date, including a range of studies that demonstrate prompt photo-induced fission of the terminal O-O bond, and speculates about possible alternate decay processes that could occur following non-adiabatic coupling to, and dissociation from, highly internally excited levels of the electronic ground state of a CI.
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Affiliation(s)
| | | | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA
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6
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Antwi E, Ratliff JM, Ashfold MNR, Karsili TNV. Comparing the Excited State Dynamics of CH 2OO, the Simplest Criegee Intermediate, Following Vertical versus Adiabatic Excitation. J Phys Chem A 2022; 126:6236-6243. [PMID: 36067494 DOI: 10.1021/acs.jpca.2c05118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio molecular dynamics studies of CH2OO molecules following excitation to the minimum-energy geometry of the strongly absorbing S2 (1ππ*) state reveal a much richer range of behaviors than just the prompt O-O bond fission, with unity quantum yield and retention of overall planarity, identified in previous vertical excitation studies from the ground (S0) state. Trajectories propagated for 100 fs from the minimum-energy region of the S2 state show a high surface hopping (nonadiabatic coupling) probability between the near-degenerate S2 and S1 (1nπ*) states at geometries close to the S2 minimum, which enables population transfer to the optically dark S1 state. Greater than 80% of the excited population undergoes O-O bond fission on the S2 or S1 potential energy surfaces (PESs) within the analysis period, mostly from nonplanar geometries wherein the CH2 moiety is twisted relative to the COO plane. Trajectory analysis also reveals recurrences in the O-O stretch coordinate, consistent with the resonance structure observed at the red end of the parent S2-S0 absorption spectrum, and a small propensity for out-of-plane motion after nonadiabatic coupling to the S1 PES that enables access to a conical intersection between the S1 and S0 states and cyclization to dioxirane products.
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Affiliation(s)
- Ernest Antwi
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70503, United States
| | - Jordyn M Ratliff
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70503, United States
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Tolga N V Karsili
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70503, United States
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7
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Takahashi K. Wave Packet Calculation of Absolute UV Cross Section of Criegee Intermediates. J Phys Chem A 2022; 126:6080-6090. [PMID: 36041057 DOI: 10.1021/acs.jpca.2c04141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Criegee intermediates, R1R2COO, are reactive species formed in the atmosphere through the ozonolysis of alkenes. They have an intense ultraviolet (UV) adsorption between 300 to 400 nm. However, experimentally determining the absolute cross sections is not easy. We used wave packet propagation on an one-dimensional adiabatic potential energy curve (PEC) along the OO bond to simulate the UV spectra for various Criegee intermediates. Our results showed a very fast, ∼20 fs, decay out of the Franck-Condon region. This gives justification for using the semiclassical approach which was utilized in previous studies. From the comparison of various quantum chemistry methods, we found that multireference methods can give spectra with a width and cross section reproducing the experimental results, while single reference methods tend to give narrower skewed peaks with a larger cross section. From the test using wave packet propagation on various approximated PECs and transition moment functions, we show that the Gaussian approximation within the reflection method is valid. In addition, we found that we can obtain peak positions that reproduce the experimental results by shifting those obtained by MRCI+Q, CASSCF, EOMCCSD, and TDCAMB3LYP by -0.2, -1.0, -0.3, and -0.5 eV, respectively. The Gaussian approximation using peak position, oscillator strength, and peak width from MRCI+Q is a cost-effective way to simulate the UV spectra of Crigee intermediates for which experimental determination may be hard.
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Affiliation(s)
- Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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8
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Antwi E, Bush RE, Marchetti B, Karsili TNV. A direct dynamics study of the exotic photochemistry of the simplest Criegee intermediate, CH 2OO. Phys Chem Chem Phys 2022; 24:16724-16731. [PMID: 35770704 DOI: 10.1039/d2cp01860h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Criegee intermediates are amongst the most fascinating molecules in modern-day chemistry. They are highly reactive intermediates that find vital roles that range from atmospheric chemistry to organic synthesis. Their excited state chemistry is exotic and complicated, and a myriad of electronic states can contribute to their photodissociation dynamics. This article reports a multi-state direct dynamics (full-dimensional) study of the photoinduced fragmentation of the simplest Criegee intermediate, CH2OO, using state-of-the-art MS-CASPT2 trajectory surface hopping. Following vertical excitation to the strongly absorbing S2(1ππ*) state, internal conversion, and thus changes in the electronic state character of the separating O + CH2O fragments, is observed between parent electronic states at separations that, traditionally, might be viewed as the classically asymptotic region of the potential energy surface. We suggest that such long-range internal conversion may account for the unusual and non-intuitive total kinetic energy distribution in the O(1D) + CH2O(S0) products observed following photoexcitation of CH2OO. The present results also reveal the interplay between seven singlet electronic states and dissociation to yield the experimentally observed O(1D) + CH2O(S0) and O(3P) + CH2O(T1) products. The former (singlet) products are favored, with a branching ratio of ca. 80%, quantifying the hitherto unknown product branching ratios observed in velocity map imaging experiments. To the best of our knowledge, such long-range internal conversions that lead to changes in the electronic state character of the fragment pairs originating from a common parent - at classically asymptotic separations - have not been recognized hitherto in the case of a molecular photodissociation.
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Affiliation(s)
- Ernest Antwi
- University of Louisiana at Lafayette, Lafayette, LA 70503, USA.
| | - Rachel E Bush
- University of Louisiana at Lafayette, Lafayette, LA 70503, USA.
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9
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Nikoobakht B. An ab initio quantum dynamics simulation of UV Absorption Spectrum of Methyl Vinyl Ketone Oxide. J Chem Phys 2022; 157:014101. [DOI: 10.1063/5.0091948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The spectroscopy of the four-carbon Criegee intermediate, methyl vinyl ketone oxide (MVK-oxide), following UV excitation to the B state (corresponding to the first $\pi^* \leftarrow \pi$ electronic transition) is studied theoretically, relied on single reference electronic wave function and a quantum dynamical approach for the nuclear motion. Two interacting electronic states $B{}^1\rm{A'}$ and $C{}^1\rm{A'}$ together with two nuclear degrees of freedom (\ce{O-O} stretching and \ce{C-O-O} bending modes) are considered in the dynamical approach. The computed absorption spectrum is found to agree well with the available experimental recordings. The existence of the weak oscillatory structures in the absorption spectrum are argued likely due to the fact that the excitation energy range of the first $\pi^* \leftarrow \pi$ electronic transition is below the energy barrier of the diabatic B state ($\sim 215$~nm) and thus below the sufficiently deep well occurring at the intermediate \ce{O-O} distances. Thissuggests the recurrences of the wavepacket, which might be considered as origin of the weak oscillatory structures in the absorption spectrum. The computed electronic excitation profile of MVK-oxide is predicted to peak at $373$ nm.
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10
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Nikoobakht B, Köppel H. Correlated quantum treatment of the photodissociation dynamics of formaldehyde oxide CH 2OO. Phys Chem Chem Phys 2022; 24:12433-12441. [PMID: 35575032 DOI: 10.1039/d2cp01007k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An extended theoretical analysis of the photodissociation of the smallest Criegee intermediate CH2OO following excitation to the B state is presented. It relies on explicitly correlated multireference electronic wavefunctions combined with a quantum dynamical treatment for two interacting (B-C) electronic states and three coupled nuclear degrees of freedom. The 3D model relies on PESs along the O-O and C-O stretching as well as C-O-O bending modes for the two lowest excited states with A' symmetry, and is sufficiently accurate to reproduce the experimental B1A'-X1A' absorption spectrum, especially at the low-energy range to unprecedented accuracy. The existence of a deep well (∼0.4 eV) on the (diabatic) B state causes a considerable amount of the wavepacket to be reflected by the B state well, which can explain the vibronic structures appearing in the long wavelength range of 360-470 nm of the spectrum. The main progression appearing in the energy range from 360 to 470 nm is assigned to the O-O stretching mode while finer details are affected by couplings to the C-O stretching and C-O-O bending modes. The weakly avoided crossing between the B-state and C-state potential energy surfaces appearing near 3.1 eV excitation energy (for RS2-F12 method) causes considerable disturbance in the vibronic fine structure of the bands. The description of the latter is quite strongly affected by the type of electron correlation treatment adopted, either fully variational (MRCI type) or perturbation theoretic (RS2 type). The results give novel insight into the complex interactions governing that intriguing process.
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Affiliation(s)
- Behnam Nikoobakht
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, INF 229, D-69120 Heidelberg, Germany.
| | - Horst Köppel
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, INF 229, D-69120 Heidelberg, Germany.
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11
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McCoy JC, Léger SJ, Frey CF, Vansco MF, Marchetti B, Karsili TNV. Modeling the Conformer-Dependent Electronic Absorption Spectra and Photolysis Rates of Methyl Vinyl Ketone Oxide and Methacrolein Oxide. J Phys Chem A 2022; 126:485-496. [PMID: 35049299 DOI: 10.1021/acs.jpca.1c08381] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Criegee intermediates are important atmospheric oxidants, formed via the reaction of ozone with volatile alkenes emitted into the troposphere. Small Criegee intermediates (e.g., CH2OO and CH3CHOO) are highly reactive, and their removal via unimolecular decay or bimolecular chemistry dominates their atmospheric lifetimes. As the molecular complexity of Criegee intermediates increases, their electronic absorption spectra show a bathochromic shift within the solar spectrum relevant to the troposphere. In these cases, solar photolysis may become a competitive contributor to their atmospheric removal. In this article, we report the conformer-dependent simulated electronic absorption spectra of two four-carbon-centered Criegee intermediates, methyl vinyl ketone oxide (MVK-oxide) and methacrolein oxide (MACR-oxide). Both MVK-oxide and MACR-oxide contain four low-energy conformers, which are convoluted in the experimentally measured spectra. Here, we deconvolute each conformer and estimate contributions from each of the four conformers to the experimentally measured spectra. We also estimate the photolysis rates and predict that solar photolysis should be a more competitive removal process for MVK-oxide and MACR-oxide (cf. CH2OO and CH3CHOO).
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Affiliation(s)
- Julia C McCoy
- Department of Chemistry, University of Louisiana at Lafayette, Louisiana, Louisiana 70503, United States
| | - Spencer J Léger
- Department of Chemistry, University of Louisiana at Lafayette, Louisiana, Louisiana 70503, United States
| | - Conrad F Frey
- Department of Chemistry, University of Louisiana at Lafayette, Louisiana, Louisiana 70503, United States
| | - Michael F Vansco
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Barbara Marchetti
- Department of Chemistry, University of Louisiana at Lafayette, Louisiana, Louisiana 70503, United States
| | - Tolga N V Karsili
- Department of Chemistry, University of Louisiana at Lafayette, Louisiana, Louisiana 70503, United States
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12
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Esposito VJ, Werba O, Bush SA, Marchetti B, Karsili TNV. Insights into the Ultrafast Dynamics of CH 2 OO and CH 3 CHOO Following Excitation to the Bright 1 ππ* State: The Role of Singlet and Triplet States. Photochem Photobiol 2021; 98:763-772. [PMID: 34767632 DOI: 10.1111/php.13560] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 11/09/2021] [Indexed: 12/11/2022]
Abstract
Criegee intermediates make up a class of molecules that are of significant atmospheric importance. Understanding their electronically excited states guides experimental detection and provides insight into whether solar photolysis plays a role in their removal from the troposphere. The latter is particularly important for large and functionalized Criegee intermediates. In this study, the excited state chemistry of two small Criegee intermediates, formaldehyde oxide (CH2 OO) and acetaldehyde oxide (CH3 CHOO), was modeled to compare their specific dynamics and mechanisms following excitation to the bright ππ* state and to assess the involvement of triplet states to the excited state decay process. Following excitation to the bright ππ* state, the photoexcited population exclusively evolves to form oxygen plus aldehyde products without the involvement of triplet states. This occurs despite the presence of a more thermodynamically stable triplet path and several singlet/triplet energy crossings at the Franck-Condon geometry and contrasts with the photodynamics of related systems such as acetaldehyde and acetone. This work sets the foundations to study Criegee intermediates with greater molecular complexity, wherein a bathochromic shift in the electron absorption profiles may ensure greater removal via solar photolysis.
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Affiliation(s)
| | | | - Sarah A Bush
- University of Louisiana at Lafayette, Lafayette, LA
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13
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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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14
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Esposito VJ, Liu T, Wang G, Caracciolo A, Vansco MF, Marchetti B, Karsili TNV, Lester MI. Photodissociation Dynamics of CH 2OO on Multiple Potential Energy Surfaces: Experiment and Theory. J Phys Chem A 2021; 125:6571-6579. [PMID: 34314179 DOI: 10.1021/acs.jpca.1c03643] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
UV excitation of the CH2OO Criegee intermediate across most of the broad span of the (B 1A')-(X 1A') spectrum results in prompt dissociation to two energetically accessible asymptotes: O (1D) + H2CO (X 1A1) and O (3P) + H2CO (a 3A''). Dissociation proceeds on multiple singlet potential energy surfaces that are coupled by two regions of conical intersection (CoIn). Velocity map imaging (VMI) studies reveal a bimodal total kinetic energy release (TKER) distribution for the O (1D) + H2CO (X 1A1) products with the major and minor components accounting for ca. 40% and ca. 20% on average of the available energy (Eavl), respectively. The unexpected low TKER component corresponds to highly internally excited H2CO (X 1A1) products accommodating ca. 80% of Eavl. Full dimensional trajectory calculations suggest that the bimodal TKER distribution of the O (1D) + H2CO (X 1A1) products originates from two different dynamical pathways: a primary pathway (69%) evolving through one CoIn region to products and a smaller component (20%) sampling both CoIn regions enroute to products. Those that access both CoIn regions likely give rise to the more highly internally excited H2CO (X 1A1) products. The remaining trajectories (11%) dissociate to O (3P) + H2CO (a 3A'') products after traversing through both CoIn regions. The complementary experimental and theoretical investigation provides insight on the photodissociation of CH2OO via multiple dissociation pathways through two regions of CoIn that control the branching and energy distributions of products.
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Affiliation(s)
- Vincent J Esposito
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Tianlin Liu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Guanghan Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Adriana Caracciolo
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Michael F Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Barbara Marchetti
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
| | - Tolga N V Karsili
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
| | - Marsha I Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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15
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Nikoobakht B, Köppel H. UV absorption spectrum and photodissociation dynamics of CH 2OO following excitation to the B1 A′ state. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1958019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Behnam Nikoobakht
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Heidelberg, Germany
| | - Horst Köppel
- Theoretische Chemie, Physikalisch-Chemisches Institut, Universität Heidelberg, Heidelberg, Germany
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16
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McCoy JC, Marchetti B, Thodika M, Karsili TNV. A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH 2OO and CH 3CHOO. J Phys Chem A 2021; 125:4089-4097. [PMID: 33970629 DOI: 10.1021/acs.jpca.1c01074] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Criegee intermediates (CIs) play a vital role in the atmosphere-known most prominently for enhancing the oxidizing capacity of the troposphere. Knowledge of their electronic absorption spectra is of vital importance for two reasons: (1) to aid experimentalists in detecting CIs and (2) in deciding if their removal is affected by solar photolysis. In this article we report a simple and efficient method based on the nuclear ensemble method that may be effectively used to compute the electronic absorption spectra of Criegee intermediates without the need for extensive computation of preparing the initial configurations of the starting geometry. We use this method to benchmark several excited-state electronic structure methods and their efficacy in reproducing the electronic absorption spectra of two well-known cases of CI: CH2OO and CH3CHOO. The success and computational feasibility of the methodology are crucial for its applicability to CIs of increasing molecular complexity, which have no known experimentally measured electronic absorption spectra, allowing a guide for experimentalists. Application of the methodology to more complex CIs (e.g., those with extended conjugation or those derived from endocyclic alkenes) will also reveal if solar photolysis becomes a competitive removal process when compared to unimolecular decay or bimolecular chemistry.
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Affiliation(s)
- Julia C McCoy
- University of Louisiana at Lafayette, Lafayette, Louisiana 70503, United States
| | - Barbara Marchetti
- University of Louisiana at Lafayette, Lafayette, Louisiana 70503, United States
| | - Mushir Thodika
- Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Tolga N V Karsili
- University of Louisiana at Lafayette, Lafayette, Louisiana 70503, United States
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17
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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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18
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Chen TY, Lee YP. Dynamics of the reaction CH 2I + O 2 probed via infrared emission of CO, CO 2, OH and H 2CO. Phys Chem Chem Phys 2020; 22:17540-17553. [PMID: 32808958 DOI: 10.1039/d0cp01940b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction CH2I + O2 has been widely employed recently for the production of the simplest Criegee intermediate CH2OO in laboratories, but the detailed dynamics of this reaction have been little explored. Infrared emission of several products of this reaction, initiated on irradiation of CH2I2 and O2 (∼8 Torr) in a flowing mixture at 308 or 248 nm, was recorded with a step-scan Fourier-transform spectrometer; possible routes of formation were identified according to the observed vibrational distribution of products and published theoretical potential-energy schemes. Upon irradiation at 308 nm, Boltzmann distributions of CO (v ≤ 5, J ≤ 19) with an average vibrational energy of 32 ± 3 kJ mol-1 and OH (v ≤ 3, J ≤ 5.5) with an average vibrational energy of 29 ± 4 kJ mol-1 were observed and assigned to the decomposition of HCOOH* to form CO + H2O and OH + HCO, respectively. The broadband emission of CO2 was simulated with two vibrational distributions of average energies (91 ± 4) and (147 ± 8) kJ mol-1 and assigned to be produced from the decomposition of HCOOH* and methylene bis(oxy), respectively. Upon irradiation of samples at 248 nm, the emission of OH and CO2 showed similar distributions with slightly greater energies, but the distribution of CO (v ≤ 11, J ≤ 19) became bimodal with average vibrational energies of (23 ± 4) and (107 ± 29) kJ mol-1, and branching (56 ± 5) : (44 ± 5). The additional large-v component is assigned to be produced from a secondary reaction HCO + O2 to form CO + HO2; HCO is a coproduct of OH. The branching between CO and OH is (50 ± 5) : (50 ± 5) at 308 nm and (64 ± 5) : (36 ± 4) at 248 nm, consistent with the mechanism according to which an additional channel to produce CO opens at 248 nm. Highly internally excited H2CO was also observed. With O2 at 16 Torr, the extrapolated nascent internal distributions are similar to those with O2 at 8 Torr except for a slight quenching effect.
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Affiliation(s)
- Ting-Yu Chen
- Department of Applied Chemistry and Institute of Molecular Science National Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science National Chiao Tung University, Hsinchu 30010, Taiwan. and Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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19
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Chhantyal-Pun R, Khan MAH, Taatjes CA, Percival CJ, Orr-Ewing AJ, Shallcross DE. Criegee intermediates: production, detection and reactivity. INT REV PHYS CHEM 2020. [DOI: 10.1080/0144235x.2020.1792104] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | - Craig A. Taatjes
- Combustion Research Facility, Sandia National Laboratories, Livermore, CA, USA
| | - Carl J. Percival
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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20
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Mir ZS, Lewis TR, Onel L, Blitz MA, Seakins PW, Stone D. CH2OO Criegee intermediate UV absorption cross-sections and kinetics of CH2OO + CH2OO and CH2OO + I as a function of pressure. Phys Chem Chem Phys 2020; 22:9448-9459. [DOI: 10.1039/d0cp00988a] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The UV absorption cross-sections of the Criegee intermediate CH2OO, and kinetics of the CH2OO self-reaction and the reaction of CH2OO with I are reported as a function of pressure at 298 K.
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Affiliation(s)
- Zara S. Mir
- School of Chemistry, University of Leeds, University of Leeds
- UK
| | - Thomas R. Lewis
- School of Chemistry, University of Leeds, University of Leeds
- UK
| | - Lavinia Onel
- School of Chemistry, University of Leeds, University of Leeds
- UK
| | - Mark A. Blitz
- School of Chemistry, University of Leeds, University of Leeds
- UK
- National Centre for Atmospheric Science, University of Leeds
- UK
| | - Paul W. Seakins
- School of Chemistry, University of Leeds, University of Leeds
- UK
| | - Daniel Stone
- School of Chemistry, University of Leeds, University of Leeds
- UK
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21
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Vansco MF, Marchetti B, Trongsiriwat N, Bhagde T, Wang G, Walsh PJ, Klippenstein SJ, Lester MI. Synthesis, Electronic Spectroscopy, and Photochemistry of Methacrolein Oxide: A Four-Carbon Unsaturated Criegee Intermediate from Isoprene Ozonolysis. J Am Chem Soc 2019; 141:15058-15069. [PMID: 31446755 DOI: 10.1021/jacs.9b05193] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ozonolysis of isoprene, one of the most abundant volatile organic compounds in the earth's atmosphere, generates the four-carbon unsaturated methacrolein oxide (MACR-oxide) Criegee intermediate. The first laboratory synthesis and direct detection of MACR-oxide is achieved through reaction of photolytically generated, resonance-stabilized iodoalkene radicals with oxygen. MACR-oxide is characterized on its first π* ← π electronic transition using a ground-state depletion method. MACR-oxide exhibits a broad UV-visible spectrum peaked at 380 nm with weak oscillatory structure at long wavelengths ascribed to vibrational resonances. Complementary theory predicts two strong π* ← π transitions arising from extended conjugation across MACR-oxide with overlapping contributions from its four conformers. Electronic promotion to the 11ππ* state agrees well with experiment, and results in nonadiabatic coupling and prompt release of O 1D products observed as anisotropic velocity-map images. This UV-visible detection scheme will enable study of its unimolecular and bimolecular reactions under thermal conditions of relevance to the atmosphere.
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Affiliation(s)
- Michael F Vansco
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Barbara Marchetti
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Nisalak Trongsiriwat
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Trisha Bhagde
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Guanghan Wang
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Patrick J Walsh
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division , Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Marsha I Lester
- Department of Chemistry , University of Pennsylvania , Philadelphia , Pennsylvania 19104-6323 , United States
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22
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Qiu J, Tonokura K. Detection of the simplest Criegee intermediate CH2OO in the ν4 band using a continuous wave quantum cascade laser and its kinetics with SO2 and NO2. Chem Phys Lett 2019. [DOI: 10.1016/j.cpletx.2019.100019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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Chang YP, Li YL, Liu ML, Ou TC, Lin JJM. Absolute Infrared Absorption Cross Section of the Simplest Criegee Intermediate Near 1285.7 cm -1. J Phys Chem A 2018; 122:8874-8881. [PMID: 30351942 DOI: 10.1021/acs.jpca.8b06759] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The ν4 fundamental of the simplest Criegee intermediate, CH2OO, has been monitored with high-resolution infrared (IR) transient absorption spectroscopy under total pressures of 4-94 Torr. This IR spectrum provides an unambiguous identification of CH2OO and is potentially useful to determine the number density of CH2OO in various laboratory studies. Here we utilized an ultraviolet (UV) and IR coupled spectrometer to measure the UV and IR absorption spectra of CH2OO simultaneously; the absolute IR cross section can then be determined by using a known UV cross section. Due to significant pressure broadening in the studied pressure range, we integrated the IR absorption spectra between 1285.2 and 1286.4 cm-1 (covering the Q branch), and then we converted this integrated absorbance to the absolute integral IR cross section of CH2OO (for the Q branch); its absolute value is (3.7 ± 0.6) × 10-19 cm·molecule-1 or 2.2 ± 0.4 km·mol-1. The whole rotational band (P, Q, and R branches) can be adequately simulated by using the precise spectroscopic parameters from the literature, yielding the absolute integral IR cross section (full ν4 band) to be 19.2 ± 3.5 km·mol-1. For a practical detection of CH2OO, this work also reports the peak cross section as a function of total pressure (4-94 Torr O2). At low pressure (≤4 Torr), where the pressure broadening is insignificant, the absorption cross section of the highest peak is (6.2 ± 0.9) × 10-18 cm2·molecule-1 (at the system line width of 0.004 cm-1 fwhm).
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Affiliation(s)
- Yuan-Pin Chang
- Department of Chemistry , National Sun Yat-sen University , Kaohsiung 80424 , Taiwan
| | - Yu-Lin Li
- Institute of Atomic and Molecular Sciences , Academia Sinica , Taipei 10617 , Taiwan.,Department of Chemistry , National Taiwan University , Taipei 10617 , Taiwan
| | - Meng-Ling Liu
- Institute of Atomic and Molecular Sciences , Academia Sinica , Taipei 10617 , Taiwan.,Air Quality Control, Solid Waste and Waste Water Process Engineering , Universität Stuttgart , Stuttgart 70569 , Germany
| | - Ting-Chun Ou
- 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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24
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Stone D, Au K, Sime S, Medeiros DJ, Blitz M, Seakins PW, Decker Z, Sheps L. Unimolecular decomposition kinetics of the stabilised Criegee intermediates CH 2OO and CD 2OO. Phys Chem Chem Phys 2018; 20:24940-24954. [PMID: 30238099 DOI: 10.1039/c8cp05332d] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Decomposition kinetics of stabilised CH2OO and CD2OO Criegee intermediates have been investigated as a function of temperature (450-650 K) and pressure (2-350 Torr) using flash photolysis coupled with time-resolved cavity-enhanced broadband UV absorption spectroscopy. Decomposition of CD2OO was observed to be faster than CH2OO under equivalent conditions. Production of OH radicals following CH2OO decomposition was also monitored using flash photolysis with laser-induced fluorescence (LIF), with results indicating direct production of OH in the v = 0 and v = 1 states in low yields. Master equation calculations performed using the Master Equation Solver for Multi-Energy well Reactions (MESMER) enabled fitting of the barriers for the decomposition of CH2OO and CD2OO to the experimental data. Parameterisations of the decomposition rate coefficients, calculated by MESMER, are provided for use in atmospheric models and implications of the results are discussed. For CH2OO, the MESMER fits require an increase in the calculated barrier height from 78.2 kJ mol-1 to 81.8 kJ mol-1 using a temperature-dependent exponential down model for collisional energy transfer with ΔEdown = 32.6(T/298 K)1.7 cm-1 in He. The low- and high-pressure limit rate coefficients are k1,0 = 3.2 × 10-4(T/298)-5.81exp(-12 770/T) cm3 s-1 and k1,∞ = 1.4 × 1013(T/298)0.06exp(-10 010/T) s-1, with median uncertainty of ∼12% over the range of experimental conditions used here. Extrapolation to atmospheric conditions yields k1(298 K, 760 Torr) = 1.1+1.5-1.1 × 10-3 s-1. For CD2OO, MESMER calculations result in ΔEdown = 39.6(T/298 K)1.3 cm-1 in He and a small decrease in the calculated barrier to decomposition from 81.0 kJ mol-1 to 80.1 kJ mol-1. The fitted rate coefficients for CD2OO are k2,0 = 5.2 × 10-5(T/298)-5.28exp(-11 610/T) cm3 s-1 and k2,∞ = 1.2 × 1013(T/298)0.06exp(-9800/T) s-1, with overall error of ∼6% over the present range of temperature and pressure. The extrapolated k2(298 K, 760 Torr) = 5.5+9.2-5.5 × 10-3 s-1. The master equation calculations for CH2OO indicate decomposition yields of 63.7% for H2 + CO2, 36.0% for H2O + CO and 0.3% for OH + HCO with no significant dependence on temperature between 400 and 1200 K or pressure between 1 and 3000 Torr.
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Affiliation(s)
- Daniel Stone
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Kendrew Au
- Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.
| | - Samantha Sime
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | | | - Mark Blitz
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Paul W Seakins
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
| | - Zachary Decker
- Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.
| | - Leonid Sheps
- Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551, USA.
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25
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Yin C, Takahashi K. How big is the substituent dependence of the solar photolysis rate of Criegee intermediates? Phys Chem Chem Phys 2018; 20:16247-16255. [DOI: 10.1039/c8cp02015a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Substituent dependence of the UV spectra of Criegee intermediates were calculated using multireference methods.
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Affiliation(s)
- 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
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26
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Luo PL, Endo Y, Lee YP. High-resolution vibration–rotational spectra and rotational perturbation of the OO-stretching (ν6) band of CH2OO between 879.5 and 932.0 cm−1. Phys Chem Chem Phys 2018; 20:25806-25811. [DOI: 10.1039/c8cp04780d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the observation of a rotationally resolved ν6 band associated with the OO-stretching mode of the simplest Criegee intermediate, CH2OO, in the range of 879.5–932.0 cm−1 (11.37–10.73 μm) at an optical resolution of 0.0015 cm−1.
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Affiliation(s)
- Pei-Ling Luo
- Department of Applied Chemistry and Institute of Molecular Science
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
| | - Yasuki Endo
- Department of Applied Chemistry and Institute of Molecular Science
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science
- National Chiao Tung University
- Hsinchu 30010
- Taiwan
- Center for Emergent Functional Matter Science
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27
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Sršeň Š, Hollas D, Slavíček P. UV absorption of Criegee intermediates: quantitative cross sections from high-level ab initio theory. Phys Chem Chem Phys 2018; 20:6421-6430. [DOI: 10.1039/c8cp00199e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Criegee Intermediates (CIs) are important intermediates in atmospheric and combustion chemistry. We quantitatively model their UV absorption spectra using ab initio techniques.
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Affiliation(s)
- Š. Sršeň
- University of Chemistry and Technology Prague
- Department of Physical Chemistry
- 16628 Prague 6
- Czech Republic
| | - D. Hollas
- University of Chemistry and Technology Prague
- Department of Physical Chemistry
- 16628 Prague 6
- Czech Republic
| | - P. Slavíček
- University of Chemistry and Technology Prague
- Department of Physical Chemistry
- 16628 Prague 6
- Czech Republic
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28
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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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29
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Kapnas KM, Toulson BW, Foreman ES, Block SA, Hill JG, Murray C. UV photodissociation dynamics of CHI 2Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate. Phys Chem Chem Phys 2017; 19:31039-31053. [PMID: 29160321 DOI: 10.1039/c7cp06532a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photolysis of geminal diiodoalkanes in the presence of molecular oxygen has become an established route to the laboratory production of several Criegee intermediates, and such compounds also have marine sources. Here, we explore the role that the trihaloalkane, chlorodiiodomethane (CHI2Cl), may play as a photolytic precursor for the chlorinated Criegee intermediate ClCHOO. CHI2Cl has been synthesized and its UV absorption spectrum measured; relative to that of CH2I2 the spectrum is shifted to longer wavelength and the photolysis lifetime is calculated to be less than two minutes. The photodissociation dynamics have been investigated using DC slice imaging, probing ground state I and spin-orbit excited I* atoms with 2 + 1 REMPI and single-photon VUV ionization. Total translational energy distributions are bimodal for I atoms and unimodal for I*, with around 72% of the available energy partitioned in to the internal degrees of freedom of the CHICl radical product, independent of photolysis wavelength. A bond dissociation energy of D0 = 1.73 ± 0.11 eV is inferred from the wavelength dependence of the translational energy release, which is slightly weaker than typical C-I bonds. Analysis of the photofragment angular distributions indicate dissociation is prompt and occurs primarily via transitions to states of A'' symmetry. Complementary high-level MRCI calculations, including spin-orbit coupling, have been performed to characterize the excited states and confirm that states of A'' symmetry with highly mixed singlet and triplet character are predominantly responsible for the absorption spectrum. Transient absorption spectroscopy has been used to measure the absorption spectrum of ClCHOO produced from the reaction of CHICl with O2 over the range 345-440 nm. The absorption spectrum, tentatively assigned to the syn conformer, is at shorter wavelengths relative to that of CH2OO and shows far weaker vibrational structure.
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Affiliation(s)
- Kara M Kapnas
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA.
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30
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Trabelsi T, Kumar M, Francisco JS. Substituent effects on the spectroscopic properties of Criegee intermediates. J Chem Phys 2017; 147:164303. [DOI: 10.1063/1.4998170] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Vansco MF, Li H, Lester MI. Prompt release of O 1D products upon UV excitation of CH2OO Criegee intermediates. J Chem Phys 2017; 147:013907. [DOI: 10.1063/1.4977987] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Michael F. Vansco
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Hongwei Li
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Marsha I. Lester
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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32
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Chang YP, Merer AJ, Chang HH, Jhang LJ, Chao W, Lin JJM. High resolution quantum cascade laser spectroscopy of the simplest Criegee intermediate, CH2OO, between 1273 cm−1 and 1290 cm−1. J Chem Phys 2017; 146:244302. [DOI: 10.1063/1.4986536] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yuan-Pin Chang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Anthony J. Merer
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia BC V6T 1Z1, Canada
| | - Hsun-Hui Chang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Li-Ji Jhang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Wen Chao
- 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
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33
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Taatjes CA. Criegee Intermediates: What Direct Production and Detection Can Teach Us About Reactions of Carbonyl Oxides. Annu Rev Phys Chem 2017; 68:183-207. [DOI: 10.1146/annurev-physchem-052516-050739] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Craig A. Taatjes
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551-0969
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34
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Ting AWL, Lin JJM. UV Spectrum of the Simplest Deuterated Criegee Intermediate CD2
OO. J CHIN CHEM SOC-TAIP 2017. [DOI: 10.1002/jccs.201700049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Allen Wei-Lun Ting
- 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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35
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Decker ZCJ, Au K, Vereecken L, Sheps L. Direct experimental probing and theoretical analysis of the reaction between the simplest Criegee intermediate CH2OO and isoprene. Phys Chem Chem Phys 2017; 19:8541-8551. [DOI: 10.1039/c6cp08602k] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of CH2OO with isoprene, the highest-emitted unsaturated compound on Earth, is similar to reactions with small singly-unsaturated alkenes.
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Affiliation(s)
- Z. C. J. Decker
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - K. Au
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
| | - L. Vereecken
- Institute for Energy and Climate Research
- Forschungszentrum Jülich GmbH
- 52428 Jülich
- Germany
| | - L. Sheps
- Combustion Research Facility
- Sandia National Laboratories
- Livermore
- USA
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36
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Liu Y, Liu F, Liu S, Dai D, Dong W, Yang X. A kinetic study of the CH2OO Criegee intermediate reaction with SO2, (H2O)2, CH2I2 and I atoms using OH laser induced fluorescence. Phys Chem Chem Phys 2017; 19:20786-20794. [DOI: 10.1039/c7cp04336h] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The OH laser induced fluorescence method was used to study the kinetics of CH2OO reacting with SO2, (H2O)2, CH2I2 and I atoms.
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Affiliation(s)
- Yiqiang Liu
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Fenghua Liu
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Siyue Liu
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Dongxu Dai
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Wenrui Dong
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
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37
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Finlayson-Pitts BJ. Introductory lecture: atmospheric chemistry in the Anthropocene. Faraday Discuss 2017; 200:11-58. [DOI: 10.1039/c7fd00161d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The term “Anthropocene” was coined by Professor Paul Crutzen in 2000 to describe an unprecedented era in which anthropogenic activities are impacting planet Earth on a global scale. Greatly increased emissions into the atmosphere, reflecting the advent of the Industrial Revolution, have caused significant changes in both the lower and upper atmosphere. Atmospheric reactions of the anthropogenic emissions and of those with biogenic compounds have significant impacts on human health, visibility, climate and weather. Two activities that have had particularly large impacts on the troposphere are fossil fuel combustion and agriculture, both associated with a burgeoning population. Emissions are also changing due to alterations in land use. This paper describes some of the tropospheric chemistry associated with the Anthropocene, with emphasis on areas having large uncertainties. These include heterogeneous chemistry such as those of oxides of nitrogen and the neonicotinoid pesticides, reactions at liquid interfaces, organic oxidations and particle formation, the role of sulfur compounds in the Anthropocene and biogenic–anthropogenic interactions. A clear and quantitative understanding of the connections between emissions, reactions, deposition and atmospheric composition is central to developing appropriate cost-effective strategies for minimizing the impacts of anthropogenic activities. The evolving nature of emissions in the Anthropocene places atmospheric chemistry at the fulcrum of determining human health and welfare in the future.
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38
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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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39
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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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40
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Absolute UV absorption cross sections of dimethyl substituted Criegee intermediate (CH 3 ) 2 COO. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.04.082] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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41
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Kalinowski J, Foreman ES, Kapnas KM, Murray C, Räsänen M, Benny Gerber R. Dynamics and spectroscopy of CH2OO excited electronic states. Phys Chem Chem Phys 2016; 18:10941-6. [DOI: 10.1039/c6cp00807k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ab initio molecular dynamics with a high level of theory is used to explore the fate of a Criegee intermediate after an initial electronic excitation. Results are confronted with experiments.
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Affiliation(s)
- Jaroslaw Kalinowski
- Department of Chemistry
- University of Helsinki
- Finland
- Max-Planck Institute for Chemical Energy Conversion
- 45470 Mülheim an der Ruhr
| | | | | | | | | | - R. Benny Gerber
- Department of Chemistry
- University of Helsinki
- Finland
- University of California
- Irvine
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