<scp>UV</scp> Spectrum of the Simplest Deuterated Criegee Intermediate <scp>CD<sub>2</sub>OO</scp>

Ting, Allen Wei-Lun; Lin, Jim J.

doi:10.1002/jccs.201700049

Cited by 17 publications

(19 citation statements)

References 32 publications

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“…Photodissociation of CH 2 OO from this excitation is reported to proceed with a quantum yield of unity (e.g. Ting et al, 2014), producing HCHO and either O( 3 P) or O( 1 D). Production of O( 1 D) has been reported to be dominant (e.g.…”

Section: Structure and Spectroscopy Of Criegee Intermediatesmentioning

confidence: 99%

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII – Criegee intermediates

Cox¹,

Ammann²,

Crowley³

et al. 2020

Atmos. Chem. Phys.

135

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Abstract. This article, the seventh in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Task Group on Atmospheric Chemical Kinetic Data Evaluation. It covers an extension of the gas-phase and photochemical reactions related to Criegee intermediates previously published in Atmospheric Chemistry and Physics (ACP) in 2006 and implemented on the IUPAC website up to 2020. The article consists of an introduction, description of laboratory measurements, a discussion of rate coefficients for reactions of O3 with alkenes producing Criegee intermediates, rate coefficients of unimolecular and bimolecular reactions and photochemical data for reactions of Criegee intermediates, and an overview of the atmospheric chemistry of Criegee intermediates. Summary tables of the recommended kinetic and mechanistic parameters for the evaluated reactions are provided. Data sheets summarizing information upon which the recommendations are based are given in two files, provided as a Supplement to this article.

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Section: Structure and Spectroscopy Of Criegee Intermediatesmentioning

confidence: 99%

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII – Criegee intermediates

Cox¹,

Ammann²,

Crowley³

et al. 2020

Atmos. Chem. Phys.

135

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“…44 Recently, Ting and Lin have reported the absorption spectrum of the deuterated Criegee intermediate, CD2OO, finding significant isotope shifts. 84 Calculations suggest that CH2OO maintains its planar structure following excitation to the B̃1A′ state, with the major geometric changes being contraction of the CO bond, extension of the OO bond and a decrease in the COO bond angle. 85,86 However, projections of the ground state vibrational wavefunctions, calculated at the MR-PT2 level, onto the B̃ state surface, suggested that three modes comprising the out-of-plane CH2 wag, CH2…”

Section: Clchoo Absorption Spectrummentioning

confidence: 99%

UV photodissociation dynamics of CHI₂Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate

Kapnas

Toulson

Foreman

et al. 2017

Phys. Chem. Chem. Phys.

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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.3

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“…Despite this, the photophysics and photochemistry of CIs have received surprisingly little attention when compared to their ground-state reactivities. The electronic absorption spectra of the small CIs (≤C 4 ) have formed the basis of some experimental ,− and theoretical − studies, and it is now understood that the absorption spectra of CIs are dominated by strongly absorbing ππ* states, local to the carbonyl oxide moiety. − ,,− The spectra of CH 2 OO and CH 3 CHOO have previously been simulated with elegant techniques that may be difficult to extend to larger CI systems. ,, Additionally, the majority of studies have used a reduced dimensionality approach for generating the initial starting geometries. Notably, Sršeň et al have shown that the computationally demanding high-order CC2/3, ADC(3), and EOM-CCSD/T methods perform well and reproduce the electronic absorption spectra of CH 2 OO and CH 3 CHOO, but these methods are restrictive for larger CIs.…”

Section: Introductionmentioning

confidence: 99%

A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH₂OO and CH₃CHOO

et al. 2021

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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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UV Spectrum of the Simplest Deuterated Criegee Intermediate CD₂OO

Cited by 17 publications

References 32 publications

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII – Criegee intermediates

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII – Criegee intermediates

UV photodissociation dynamics of CHI₂Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate

A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH₂OO and CH₃CHOO

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UV Spectrum of the Simplest Deuterated Criegee Intermediate CD2OO

Cited by 17 publications

References 32 publications

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII – Criegee intermediates

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume VII – Criegee intermediates

UV photodissociation dynamics of CHI2Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate

A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH2OO and CH3CHOO

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UV Spectrum of the Simplest Deuterated Criegee Intermediate CD₂OO

UV photodissociation dynamics of CHI₂Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate

A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH₂OO and CH₃CHOO