Theoretical Study on the Reaction Mechanism and Kinetics of Criegee

Oct 17, 2018 - The detailed reaction mechanism and kinetics of Criegee intermediate CH2OO with acrolein were investigated. CH2OO may add to the C=O or...
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A: Spectroscopy, Molecular Structure, and Quantum Chemistry

Theoretical Study on the Reaction Mechanism and Kinetics of Criegee Intermediate CHOO with Acrolein 2

Cuihong Sun, Shaoyan Zhang, Junyong Yue, and Shaowen Zhang J. Phys. Chem. A, Just Accepted Manuscript • DOI: 10.1021/acs.jpca.8b06897 • Publication Date (Web): 17 Oct 2018 Downloaded from http://pubs.acs.org on October 19, 2018

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Theoretical Study on the Reaction Mechanism and Kinetics of Criegee Intermediate CH2OO with Acrolein

Cuihong Sun,†, ‡,* Shaoyan Zhang,† Junyong Yue,† and Shaowen Zhang‡,*

†College ‡School

of Chemical Engineering, Shijiazhuang University, Shijiazhuang, 050035, P. R. China

of Chemistry and Chemical Engineering, Key Laboratory of Cluster Science of Ministry

of Education, Beijing Institute of Technology, 100081, P. R. China

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ABSTRACT The detailed reaction mechanism and kinetics of Criegee intermediate CH2OO with acrolein were investigated. CH2OO may add to the C=O or C=C double bond of acrolein to form a five-membered ring adducts, and it may also insert the terminal oxygen atom or insert itself into the C-H bond of acrolein. The addition reactions are more favorable in energy than the insertion reactions. The master equation calculation show that the most competitive reaction channel is the 1,3-cycloaddition of CH2OO across the C=O double bond forming the secondary ozonide (SOZ). The lowest energy pathway for SOZ decomposition involves the formation of the singlet biradical intermediate by ring fission, the H-shift isomerization and the dissociation to products. The calculated overall rate constant decreases as the temperature increases from 200 K to 500 K, and at 298 K, it is 4.31×10-12 cm3 molecule-1 s-1. The branching ratio of collisionally stabilized SOZ increases with the increase of pressure. At low pressure, some of SOZ decompose to HCOOH + acrolein or HCHO + acrylic acid. The pressure dependence of this reaction is in agreement with the previous theoretical and experimental observations for the reaction of CH2OO with acetaldehyde.

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1. INTRODUCTION Criegee intermediates (CI) are known as the carbonyl oxides generated from the alkenes ozonolysis. The alkenes ozonolysis proceeds via 1,3-cycloaddition of O3 to the alkene π-system forming the primary ozonide (POZ), and then ring fission in POZ producing Criegee intermediate and a carbonyl compound (Scheme 1). The energised CI will undergo unimolecular decomposition or collisional stabilization, and the stabilized CI will react easily with other atmospheric species because of its high reactivity.1

Scheme 1. The formation of Criegee intermediates from alkene ozonolysis, where R represents H atom or any alkyl substituent. Due to the importance of alkenes ozonolysis reaction in the atmosphere, the CI and their reactions with other species have attracted much attention. In the early years the experimental studies were often done indirectly with several assumptions and the results were made with high uncertainties because of the short lifespan of CI and lack of direct precursors; furthermore, there existed significant difference between the experimental observation and theoretical prediction. Since the ground-breaking experiments of the direct detection of CH2OO by Welz et al.2 in 2012, more and more new experimental determinations for the molecular structure, spectroscopy, unimolecular and bimolecular reactions of CI have been catalysed.3-19 At the same time, more detailed prediction and elucidation are obtained by theoretical studies, especially for the

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reactions that are not readily accessible in the lab, as well as the temperature and pressure dependence for some reactions.20-31 So theoretical study based on the high-level quantum computation is an effective tool to predict the reaction mechanism of CI with other species especially for those beyond the experimental observations. Carbonyl compounds has been used as ‘‘Criegee scavenger’’ for indirect measurements of CI kinetics.32 In addition, both carbonyl compound and CI are the products of POZ ring fission in alkenes ozonolysis. The reaction mechanism and kinetics characters of the simplest CI (CH2OO) with formaldehyde, acetaldehyde, acetone, and hexafluoro acetone have been investigated.6, 17, 18, 32

The reaction proceeds firstly via 1,3-cycloaddition of CH2OO across the C=O bond of

carbonyl compound forming secondary ozonide (SOZ), which is similar to the reaction of O3 with carbonyl compound. Subsequently, the SOZ undergo isomerization and decomposition to form organic acid and carbonyl compound. Both the experimental observation by Taatjes et al.17 and Stone et al.6 and the theoretical work of Jalan et al.18 show that the collisional stabilisation of SOZ dominate the CH2OO + acetaldehyde reaction at high pressure, while HCHO and acetic acid are the dominant products at low pressure. CI can also react with alkenes by 1,3-cycloaddition to the C=C bond of alkene forming the cyclic peroxide.19, 20, 33 The theoretical study performed by Vereecken et al.20 suggests that the reaction of CI with olefines is highly dependent on the substitution in alkene and CI. The theoretical and experimental investigations mentioned above focus on the reaction of CI with carbonyl compound and alkene, respectively. Both the C=C and C=O double bonds are involved in the unsaturated carbonyl compounds. The unsaturated carbonyl compounds play an

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important role in the atmospheric and environmental sciences due to their large concentrations and high reactivity at the tropospheric level. They are produced by direct anthropogenic emissions or by the oxidation of dienes. For exmple, acrolein is the main product of the butadiene oxidation, methyl vinyl ketone and methacrolein are the major products of isoprene oxidation.34,

35

More recently, the bimolecular reaction rate coefficients of CH2OO + methyl

vinyl ketone and CH2OO + methacrolein reactions were determined by Eskola et al.36 Based on the adiabatic ionization energy calculations and the master equation calculations they inferred that the adducts are most likely secondary ozonides (1,2,4-trioxolanes) formed by CH2OO addition to the C=O bonds. Considering the potential importance of the reaction of CH2OO with unsaturated carbonyl compounds, it is necessary to understand the detailed reaction mechanism involving the addition to the C=C and C=O double bonds, as well as the subsequent isomerization and decomposition of the secondary ozonides. In this work, we will investigate the possible reaction channels between the simplest CI (CH2OO) with acrolein to give an integrated potential energy profile and reaction mechanism. CI is known as a 1,3-bipole radical with zwitterionic character, and a large amount of studies have suggested that it has two reactive sites in the addition reactions, namely the carbon atom and the terminal oxygen atom.29, 37, 38 In reactions with unsaturated species,17, 18, 19, 20, 33 it often reacts by 1,3-cycloaddition reactions. In reactions with CO, NO, SO2, and NO2,6,

23, 26, 39

CI acts as an

oxygen atom donor. In reactions with atmospheric species contain hydrogen atoms, such as H2O, NH3, CH4, HCl, et al.,22,

29, 40-44

it inserts itself into the O-H, N-H, or C-H bond, forming a

substituted peroxide. All of these possible reaction mechanisms have been applied to the CI +

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acrolein reaction. Based on the high level potential energy profile, the master equation (ME) calculations have been performed to predict the overall rate constants and products' branching ratios at different temperature and pressure; the importance of the C=C and C=O addition has been discussed. Our studies are expected to provide useful information for further investigation for the reactions of Criegee intermediate with unsaturated carbonyl compound. 2. COMPUTATIONAL METHOD 2.1 Electronic structure calculations All the geometries of the stationary points for the CH2OO + acrolein reaction singlet potential energy surface (PES) were optimized at the M06-2X/aug-cc-pVTZ level of theory. The hybrid meta-density functional theory M06-2X developed by Truhlar et al.45 has been proved to be efficient and accurate in predicting the main-group thermochemistry and kinetics properties.46-48 The vibrational frequency analysis was performed at the same level of theory to identify the local minima and transition states (TS) according to the number of the imaginary frequencies (NIMAG = 0 or 1, respectively). The restricted formalism (RM06-2X) was used for the closed shell reactants, complexes, intermediate, products and transition states, while the unrestristed formalism (UM06-2X) with mix of the highest occupied molecular orbital and the lowest unoccupied molecular orbital was used for the singlet biradicals and the connected transition states. The intrinsic reaction coordinate (IRC) calculations were performed to verify that each transition state indeed connect with its corresponding minima. To obtain more reliable energetic results, the higher-level (denoted as HL) single-point energy calculations have been carried out.49 The HL method widely used by Miller and Klippenstein49 employs a combination of CCSD(T)

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and MP2(FC) methods and can be expressed as EHL=E[CCSD(T)/cc-pVTZ] + (E[CCSD(T)/cc-pVTZ] − E[CCSD(T)/cc-pVDZ])*0.46286 + E[MP2(FC)/cc-pVQZ]

+

(E[MP2(FC)/cc-pVQZ]



E[MP2(FC)/cc-pVTZ])*0.69377



E[MP2(FC)/cc-pVTZ] − (E[MP2(FC)/cc-pVTZ] − E[MP2(FC)/cc-pVDZ]) *0.46286 The HL method is a dual-level theory including the extrapolation to the infinite basis set limit, which can give more accurate energies for rate constants calculation.49,

50

All the electronic

structure and energetic calculations were carried out by the Gaussian 09 program package.51 2.2 Rate Constant Calculations The master equation method52-56 was used to calculate the overall rate constant and the pressure dependent products' branching ratios. The RRKM approach is employed to evaluate the microcanonical rate constants k(E), for which the variational effect is not included and the Eckart tunneling effect is incorporated for the H-shift reactions. Energy transfer is treated with the single exponential down model with ΔEdown = 200 cm−1. The Lennard-Jones (L-J) parameters of the addition intermediates (C4O3H6) are approximately taken as σ = 6.0 Å and ε/kb = 450 K,57 and the L-J parameters of N2 are taken as σ = 3.9 Å and ε/kb = 48 K.52 In this study, the master equation was solved by an ordinary differential equation (ODE) solver to evolve directly the number population of the species with time.58-60 The populations of species as functions of time can be obtained directly and the first-order rate constants can be extracted from the reactant population using the “exponential decay” approach. The detailed description on the ME method can be found in Ref.50, 60-62. All the kinetic calculations were carried out by using TheRate program.63

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3. RESULTS AND DISCUSSION 3.1. Reaction mechanisms of CH2OO + acrolein 3.1.1. The reaction complexes

Figure 1. Molecular graphs of the reaction complexes. Bond critical points are shown as small red spherea and ring critical points are shown as small yellow spherea. The two reactant monomers approach each other to form several van der Waals complexes. According to the atoms in molecules theory (AIM),64-66 the bond critical point (BCP) indicates the existence of the interatomic interaction, and the ring critical point (RCP) indicates the existence of a ring structure. The molecular graphs of the reaction complexes are shown in Figure 1. As shown in Figure 1, there exists BCPs and RCP in every complex, which means the interactions of the two approaching reactant monomers. The atomic distances of the weak interactions and the relative energies of the reactant complexes are listed in Table 1.

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Table 1. The atomic distances (in Å) of the weak interactions and the relative energy (in kcal mol-1) of the reactant complexes Species Com1a Com1b Com2a Com3b Com3c Com4c

Interactions

Atomic distances

C3…O7 O4…C5 C3…O7 O4…C5 C1…O7 C2…C5 O4…H12 O7…H10 O7…H8 O7…H10 C1…O7 C2…C5

2.57 2.56 2.62 2.55 2.74 2.96 2.13 2.26 2.35 2.55 2.72 2.95

Relative energy -6.4 -6.3 -4.0 -5.9 -2.6 -3.8

The CH2OO radical approaches C=O double bond in the direction vertical to the molecular plane of acrolein forming Com1a and Com1b. In Com1a, the atomic distances of C3…O7 and O4…C5 are 2.57 and 2.56 Å, respectively; In Com1b, the atomic distances of C3…O7 and O4… C5 are 2.62 and 2.55 Å. The respective energies of Com1a and Com1b are -6.4 and -6.3 kcal mol-1 relative to the total energy of the reactants. The CH2OO radical approaches π orbital of the C=C double bond in the direction vertical to the molecular plane of acrolein forming Com2a (-4.0 kcal mol-1) and Com4c (-3.8 kcal mol-1). In Com2a, the respective atomic distances of C1… O7 and C2…C5 are 2.74 and 2.96 Å; In Com4c, the atomic distances of C1…O7 and C2…C5 are 2.72 and 2.95 Å. Com3b and Com3c are formed by the hydrogen bonds between O and H atoms. In Com 3b, the atomic distances of O4…H12 and O7…H10 are 2.13 and 2.26 Å; In Com 3c, the respective atomic distances of O7…H8 and O7…H10 are 2.35 and 2.55 Å. The relative energies of Com3b and Com3c are -5.9 and -2.6 kcal mol-1, respectively.

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3.1.2. The reaction channels

Figure 2. Calculated mechanism and optimized geometries of the intermediates, transition states, and products. (A) Addition reaction to C=O bond; (B) Addition reaction to C=C bond.

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Starting from these reactant complexes, CH2OO may add to the C=O or C=C double bond, and it may also insert the terminal oxygen atom or insert itself to the C-H bonds of acrolein. The calculated mechanism and optimized geometries of the intermediates, transition states, and products at the M06-2X/aug-cc-pVTZ level of theory are shown in Figure 2, and the refined potential energy surfaces at the HL level of theory are shown in Figure 3. The atomic distances and the relative energies of the transition states are listed in Table 2. For the addition reaction to C=O double bond, there are two addition types, one is C atom and the terminal O atom of CH2OO adding to the O and C atoms of the aldehyde group, respectively, i.e., C5 to O4 and O7 to C3 addition; the other is C5 to C3 and O7 to O4 addition. The above two addition types are defined as 1a and 1b respectively, as shown in Figure 2A. The PES of the addition reaction to C=O bond is shown in Figure 3A. In reaction 1a, CH2OO approaches the C=O double bond forming the complexes Com1a, which lies -6.4 kcal mol-1 below the biomolecular reactants, and this leads to the formation of the secondary ozonide (IM1a) by 1,3-cycloaddition (TS1a) of CH2OO across the C=O bond of acrolein. This addition reaction is 46.3 kcal mol-1 exothermic, and the energized IM1a may isomerize to a 1,4-singlet biradical intermediate IM1aI1 by ring opening or decompose to stable products via transition states TS1aD3 or TS1aD4. The relative energies of the transition states TS1aD3 and TS1aD4 are -5.2 and -3.6 kcal mol-1, respectively. TS1aD3 involves the concerted dissociation of the O4-C5 and O7-O6 bonds in IM1a accompanied by the insertion of O7 to C2-C3 bond, and the decomposition products are CH2CHOCHO and HCHO (-99.8 kcal mol-1); TS1aD4 involves the concerted dissociation of the C3-O4 and O7-O6 bonds in IM1a accompanied by simultaneous

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H-shift from the CH2 group to the adjacent O6 atom, and the corresponding decomposition products are formic acid and acrolein (-117.2 kcal mol-1). Similar to the reaction of CH2OO + HCHO reported by Jalan and coworkers18, the formation of the 1,4-singlet biradical intermediate IM1aI1 by breaking the O6-O7 bond in IM1a via TS1aI1 is more favorable in energy. The relative energies of TS1aI1 and IM1aI1 are -15.2 and -17.5 kcal mol-1, respectively. The H-shift from C5 to O7 in IM1aI1 leads to the extremely exothermic formation of intermediate IM1aI2 (-123.1 kcal mol-1), which subsequently decompose to formic acid and acrolein by the breaking of C3-O4 bond and simultaneous H-shift from O7 to O6 (TS1aD1, -106.8 kcal mol-1). On the other hand, the H-shift from C3 to O6 in IM1aI1 leads to the formation of IM1aI3 (-127.3 kcal mol-1), and then O4-C5 bond breaks and H shifts from O6 to O7 simultaneously (TS1aD2, -106.8 kcal mol-1) forming the decomposition products acrylic acid and HCHO (-114.5 kcal mol-1). In reaction 1b, CH2OO approaches the C=O double bond forming the complexes Com1b, and then the C atom and the terminal O atom of CH2OO add to the C and O atoms of the C=O double bond of acrolein forming the intermediate IM1b, which subsequently decomposes to CH2CHCHOO and HCHO. The relative energies of addition transition state TS1b and decomposition transition states TS1bD are 21.1 and 21.3 kcal mol-1. It is not difficult to find from Figure 3A that the reaction 1b is obvious less competitive than reaction 1a. Furthermore, in reaction 1a, for the adduct IM1a (SOZ), the ring opening-isomerization-decomposition process is more favorable in energy than the direct decomposition process. The singlet biradical intermediate IM1aI1 is actually a shallow well, and this means it can rapidly equilibrate with IM1a. As a result, we omit the intermediate IM1aI1 from the subsequent master equation

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calculation and treat the H-shift (TS1aI2) as an isomerization leading directly to IM1aI2 or IM1aI3. This treatment has been elaborated and proved reasonable by Jalan and coworkers18 in the CH2OO + formaldehyde (or acetaldehyde) reaction. Table 2. The atomic distances (in Å) and the relative energy (in kcal mol-1) of the transition states Species

Interactions

TS1a

C3-O7

Atomic distances 2.19

O4-C5 O6-O7 C5-H12 O7-H12 C3-H11 O6-H11 C3-O4 O6-H12 O7-H12 O4-C5 O6-H11

2.18 2.05 1.20 1.65 1.22 1.70 1.93 1.24 1.18 1.81 1.31

O7-H11 O4-C5 O6-O7 C2-O7 C3-O4 O6-O7 O6-H13 C3-C5 O4-O7 C3-C5 O6-O7

1.12 1.61 1.98 1.74 1.80 1.85 1.43 1.91 1.98 1.91 1.97

TS1aI1 TS1aI2 TS1aI3 TS1aD1

TS1aD2

TS1aD3

TS1aD4

TS1b TS1bD

a

Relative energy a -4.6

Species

Interactions

TS2a

C1-O7

Atomic distances 2.25

C2-C5 O6-O7 C5-H12 O7-H12 C1-C2 O6-H12 O7-H12 C2-C5 O6-O7 C3-H8 C1-C5

2.46 2.22 1.19 1.62 2.07 1.17 1.24 1.95 2.08 1.73 2.34

C2-O7 O6-O7 C5-H12 O7-H12 C1-C2 O6-H12 O7-H12 C1-C5 O6-O7 C1-C5 O6-O7 C1-H10

2.40 2.16 1.19 1.64 2.04 1.13 1.51 1.87 2.16 1.87 2.12 1.66

-15.2 -12.6

TS2aI1 TS2aI2

-12.7

TS2aD1

-106.8 TS2aD2 -106.8 TS2b -5.2

TS2bI1 TS2bI2

-3.6

TS2bD1

21.1

TS2bD2

21.3

TS2bD3

Relative energy a -1.4 -21.1 -20.0 -83.0

-15.2

0.3 -25.3 -21.3 -79.4

-20.2 -18.9

The total energy of the reactants is set as zero for reference.

There are also two addition types in the addition reaction to C=C double bond, which defined

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as 2a and 2b. As shown in Figure 2B, the 2a addition is the terminal O and C atoms of CH2OO adding to the terminal and central C atoms of C=C double bond of the aldehyde group, respectively, i.e., O7 to C1 and C5 to C2 addition; the 2b addition is C5 to C1 and O7 to C2 addition. The PES of the addition reaction to C=C bond is shown in Figure 3B. The reaction process is similar to that of addition to C=O double bond, we omit the singlet biradical intermediate on the PES as well for the reason discussed above. In reaction 2a, the reaction complex Com2a and intermediate IM2a subsequently form as CH2OO approaches the C=C double bond. The relative energies of TS2a and IM2a are -1.4 and -57.1 kcal mol-1, respectively. IM2a may proceed ring fission forming singlet biradical intermediate (TS2aI1, -21.1 kcal mol-1), H-shift isomerization (TS2aI2, -20.0 kcal mol-1) and decomposition reaction (TS2aD1, -83.0 kcal mol-1) to produce CH(OH)CHCHO and HCHO; and it may also decompose to malonaldehyde and HCHO by the concerted rupture of C2-C5 and O7-O6 bonds in IM2a accompanied by H-shift from C1 to C2 atom (TS2aD2, -15.2 kcal mol-1). In reaction 2b, it is worth mentioning that we failed to locate the anticipative Com2b formed by the weak interaction of C5…C1 and O7 … C2 as CH2OO approaches the C=C double bond, because of the stronger electrostatic interaction between CH2OO and C=O double bond. As a result, Com2b is formed by the interaction of O7 … C3 and C5 … O4 (Figure 1), and then CH2OO shifts to C=C bond accompanied by the rotation of C5 to C1 atom leading to the formation of IM2b. Starting from IM2b, the reaction may proceed ring fission forming singlet biradical intermediate (TS2bI1, -25.3 kcal mol-1), H-shift isomerization (TS2bI2, -21.3 kcal mol-1) and decomposition reaction (TS2bD1, -79.4 kcal mol-1) to form ethenol and glyoxal; and IM2b may also decompose to

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malonaldehyde + HCHO via TS2bD2 (-20.2 kcal mol-1) or CH3COCHO + HCHO via TS2bD3 (-18.9 kcal mol-1). TS2bD2 involves the rupture of C1-C5 bond and the simultaneous insertion of CH2 group to C2-C3 bond, and TS2bD3 involves the rupture of C1-C5 bond and the accompanied H-shift from C2 to C1. From Figure 3B we can see that the reaction channels of forming singlet biradical intermediate are more favorable in energy. The terminal oxygen atom of CH2OO may insert to the C-H bonds of acrolein forming crylic acid + HCHO or hydroxy-substituted acrolein + HCHO. The insertion reaction of O to the C3-H, C2-H, and C1-H are defined as 3a, 3b, and 3c, respectively. CH2OO may also insert itself to the C-H bonds, the reaction proceeds via the breakage of C-H bond and the formation of new C-C and O-H bonds. The insertion reaction of CH2OO to the C3-H, C2-H, and C1-H are defined 4a, 4b, and 4c, respectively. The optimized geometries of the transition states and products for the insertion reactions are given in Figure S1, and the PESs of the two insertion reactions are shown in Figure 3C and 3D. From the PESs in Figure 3 we can see that the reaction energy barriers in the insertion reactions are much higher than those of the addition reactions. The addition reaction to C=O or C=C are barrierless (reaction 1a, 1b, and 2a) or low-barrier reaction (reaction 2b), and most of the stationary points' energies in the addition reactions are lower than that of the reactants, especially the channels involving the formation of singlet biradical intermediate, the H-shift isomerization and decomposition are more competitive in energy. So these addition reaction channels will be involved in the subsequent master equation calculation.

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Figure 3. HL// M06-2X/aug-cc-pVTZ potential energy surfaces (including zero-point corrections) for CH2OO + acrolein (omitting the biradical intermediates in Figure 3b), the total energy of the reactants is set as zero for reference, and the relative energies are given in kcal mol−1. (A) Addition reaction to the C=O bond; (B) Addition reaction to the C=C bond; (C) Insertion reaction of the terminal oxygen atom to the C-H bonds; (D) Insertion reaction of CH2OO itself to the C-H bonds. 3.2. Rate Constants Calculations In order to evaluate the pressure and temperature dependent rate constants and the branching ratios of the products, and identify which is more competitive between the C=O and C=C

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addition reactions, the master equation calculations were carried out at the pressure range of 1-760 Torr and the temperature range of 200-500 K based on the M06-2X/aug-cc-pVTZ optimized geometries with energies refined by the HL method. According to the PESs of CH2OO + acrolein reaction, the addition reactions to the C=O and C=C which proceeding via addition, ring fission, isomerization, and decomposition are included in the master equation calculation.

Figure 4. The overall rate constants of CH2OO + acrolein reaction at the temperature range of 200-500 K. Table 3. The values of the overall rate constants (in cm3 molecule-1 s-1) of CH2OO + acrolein reaction at the temperature range of 200-500 K. Temperature

200

250

298

350

400

450

500

Rate constants 1.67E-10 1.74E-11 4.31E-12 1.55E-12 7.81E-13 4.75E-13 3.30E-13 The calculated rate constants versus temperature at 760 Torr are shown in Figure 4, and the values are listed in Table 3. It can be seen that the rare constant decreases gradually as the temperature ranges from 200 K to 500 K, this is because the rate-determining step is the barrierless addition reaction at 760 Torr, which has been proved showing negative temperature

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effect.67-69 At 298K, the overall rate constant is 4.31 × 10-12 cm3 molecule-1 s-1, which is close to the values of k (CH2OO + MVK) = (5.0 ± 0.4) × 10-13 cm3 molecule-1 s-1, k (CH2OO + MACR) = (4.4 ± 1.0) × 10-13 cm3 molecule-1 s-1,36 and k (CH2OO + CH3CHO) = (9.5 ± 0.7) × 10-13 or (1.48 ± 0.04) × 10-12 cm3 molecule-1 s-1.6, 17

Figure 5. The products branching ratio at the pressure range of 1-760 Torr. The products' branching ratios at different pressures and 298 K are shown in Figure5. The calculated branching ratio of all the species in the addition reaction to C=C double bond approximate to zero and can be negligible at the pressure range of 1-760 Torr, i.e., the adducts are formed mainly by CH2OO addition to the C=O bonds, which is in agreement with the results of Eskola et al.36 for the analogous reaction of CH2OO with methyl vinyl ketone and methacrolein. As pressure increases from 1 Torr to 50 Torr, the branching ratio of SOZ increases from 34% to 95%, while the branching ratio decreases from 41% to 3% for P1aD1 (HCOOH + acrolein) and decreases from 25% to 2% for P1aD2 (HCHO + acrylic acid). At the atmospheric pressure (760 Torr), SOZ becomes the only major products, and the reaction is dominated by the collisionally stabilized of SOZ. The change trend of the products' branching ratio with pressure is

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agreement with that of the reaction of CH2OO with acetaldehyde. 6, 17, 18, 32 As discussed above, the rate constant of the CH2OO + acrolein reaction shows negative temperature effect at the 760 Torr and given temperature range. The calculated rate constant at 298 K is close to those of the reactions of CH2OO with acetaldehyde,6, 17 methyl vinyl ketone and methacrolein.36 CH2OO mainly adds to C=O double bond forming IM1a (SOZ), and some of SOZ decomposes to acrolein + HCOOH and acrylic acid + HCHO at low pressure. 4. CONCLUSIONS The reaction mechanism of CH2OO with acrolein has been investigated at the HL//M06-2X/aug-cc-pVTZ level of theory. The rate constants are calculated by the master equation method with the Eckart tunneling corrections. The following conclusions can be drawn. (1) The addition reaction of CH2OO to the C=O or C=C double bonds is more competitive than the insertion reaction. (2) The reaction mainly proceeds by CH2OO adding to the C=O double bond to form secondary ozonide. SOZ can be collisionally stabilized at high pressure, and at low pressure it trend to decompose to acrolein + HCOOH and acrylic acid + HCHO; (3) The rate constant of the CH2OO + acrolein reaction shows negative temperature effect at the temperature range of 200 K to 500 K and 760 Torr; At 298K, it is 4.31 × 10-12 cm3 molecule-1 s-1. The calculated rate constant is close to those of the analogue reactions of CH2OO with acetaldehyde, methyl vinyl ketone and methacrolein, and the pressure effect of the products' branching ratio is similar to that of the reaction of CH2OO with acetaldehyde.6, 17, 36

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Supporting Information Available: The optimized geometries of the transition states and products for the insertion reactions at the M06-2X/aug-cc-pVTZ level of theory. This material is available free of charge via the Internet at http://pubs.acs.org.

AUTHOR INFORMATION Corresponding Author * E-mail: [email protected] and [email protected]

ACKNOWLEDGMENT This work is supported by the National Natural Science Foundation of China (No. 21603152 and 21673018), Scientific Research Foundation for University of Hebei Province (Z2018015) and the Foundation of Shijiazhuang University (No. 14BS003, 2018-6X and 16BS003).

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REFERENCES (1) Vereecken, L.; Francisco, J. S. Theoretical Studies of Atmospheric Reaction Mechanisms in the Troposphere. Chem. Soc. Rev. 2012, 41, 6259-6293. (2) Welz, O.; Savee, J. D.; Osborn, D. L.; Vasu, S. S.; Percival, C. J.; Shallcross, D. E.; Taatjes, C. A. Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of CH2I with O2. Science 2012, 335, 204-207. (3) Ouyang, B.; McLeod, M. W.; Jones, R. L.; Bloss, W. J. NO3 Radical Production from the Reaction between the Criegee Intermediate CH2OO and NO2. Phys. Chem. Chem. Phys. 2013, 15, 17070-17075. (4) Taatjes, C. A.; Welz, O.; Eskola, A. J.; Savee, J. D.; Scheer, A. M.; Shallcross, D. E.; Rotavera, B.; Lee, E. P.; Dyke, J. M.; Mok, D. K. et al. Direct Measurements of Conformer-Dependent Reactivity of the Criegee Intermediate CH3CHOO. Science 2013, 340, 177-180. (5) Berndt, T.; Voigtlander, J.; Stratmann, F.; Junninen, H.; Mauldin, R. L., 3rd; Sipila, M.; Kulmala, M.; Herrmann, H. Competing Atmospheric Reactions of CH2OO with SO2 and Water Vapour. Phys. Chem. Chem. Phys. 2014, 16, 19130-19136. (6) Stone, D.; Blitz, M.; Daubney, L.; Howes, N. U.; Seakins, P. Kinetics of CH2OO Reactions with SO2, NO2, NO, H2O and CH3CHO as a Function of Pressure. Phys. Chem. Chem. Phys. 2014, 16, 1139-1149. (7) Chao, W.; Hsieh, J. T.; Chang, C. H.; Lin, J. J. Atmospheric Chemistry. Direct Kinetic Measurement of the Reaction of the Simplest Criegee Intermediate with Water Vapor. Science 2015, 347, 751-754. (8) Lewis, T. R.; Blitz, M. A.; Heard, D. E.; Seakins, P. W. Direct Evidence for a Substantive Reaction between the Criegee Intermediate, CH2OO, and the Water Vapour Dimer. Phys. Chem. Chem. Phys. 2015, 17, 4859-4863. (9) Newland, M. J.; Rickard, A. R.; Alam, M. S.; Vereecken, L.; Munoz, A.; Rodenas, M.; Bloss, W. J. Kinetics of Stabilised Criegee Intermediates Derived from Alkene Ozonolysis: Reactions with SO2, H2O and Decomposition under Boundary Layer Conditions. Phys. Chem. Chem. Phys. 2015, 17, 4076-4088. (10) Caravan, R. L.; Khan, M. A. H.; Rotavera, B.; Papajak, E.; Antonov, I. O.; Chen, M. W.; Au, K.; Chao, W.; Osborn, D. L.; Lin, J. J. et al. Products of Criegee Intermediate Reactions with NO2: Experimental Measurements and Tropospheric Implications. Faraday Discuss. 2017, 200, 313-330. (11) 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. (12) Ting, W.-L.; Chang, C.-H.; Lee, Y.-F.; Matsui, H.; Lee, Y.-P.; Lin, J. J.-M. Detailed Mechanism of the CH2I + O2 Reaction: Yield and Self-Reaction of the Simplest Criegee Intermediate CH2OO. J. Chem. Phys. 2014, 141, 104308. (13) Ahrens, J.; Carlsson Philip, T. M.; Hertl, N.; Olzmann, M.; Pfeifle, M.; Wolf, J. L.; Zeuch, T. Infrared Detection of Criegee Intermediates Formed During the Ozonolysis of β-Pinene and Their Reactivity Towards Sulfur Dioxide. Angew. Chem. Int. Ed. 2014, 53, 715-719. (14) Buras, Z. J.; Elsamra, R. M.; Green, W. H. Direct Determination of the Simplest Criegee Intermediate (CH2OO) Self Reaction Rate. J. Phys. Chem. Lett. 2014, 5, 2224-2228. (15) Berndt, T.; Jokinen, T.; Mauldin, R. L.; Petäjä, T.; Herrmann, H.; Junninen, H.; Paasonen, P.; Worsnop, D. R.; Sipilä, M. Gas-Phase Ozonolysis of Selected Olefins: The Yield of Stabilized Criegee Intermediate and the Reactivity toward SO2. J. Phys. Chem. Lett. 2012, 3, 2892-2896.

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(16) Welz, O.; Eskola Arkke, J.; Sheps, L.; Rotavera, B.; Savee John, D.; Scheer Adam, M.; Osborn David, L.; Lowe, D.; Murray Booth, A.; Xiao, P. et al. Rate Coefficients of C1 and C2 Criegee Intermediate Reactions with Formic and Acetic Acid near the Collision Limit: Direct Kinetics Measurements and Atmospheric Implications. Angew. Chem. 2014, 126, 4635-4638. (17) Taatjes, C. A.; Welz, O.; Eskola, A. J.; Savee, J. D.; Osborn, D. L.; Lee, E. P.; Dyke, J. M.; Mok, D. W.; Shallcross, D. E.; Percival, C. J. Direct Measurement of Criegee Intermediate (CH2OO) Reactions with Acetone, Acetaldehyde, and Hexafluoroacetone. Phys. Chem. Chem. Phys. 2012, 14, 10391-10400. (18) Jalan, A.; Allen, J. W.; Green, W. H. Chemically Activated Formation of Organic Acids in Reactions of the Criegee Intermediate with Aldehydes and Ketones. Phys. Chem. Chem. Phys. 2013, 15, 16841-16852. (19) Buras, Z. J.; Elsamra, R. M.; Jalan, A.; Middaugh, J. E.; Green, W. H. Direct Kinetic Measurements of Reactions between the Simplest Criegee Intermediate CH2OO and Alkenes. J. Phys. Chem. A 2014, 118, 1997-2006. (20) Vereecken, L.; Harder, H.; Novelli, A. The Reactions of Criegee Intermediates with Alkenes, Ozone, and Carbonyl Oxides. Phys. Chem. Chem. Phys. 2014, 16, 4039-4049. (21) Kurten, T.; Lane, J. R.; Jorgensen, S.; Kjaergaard, H. G. A Computational Study of the Oxidation of SO2 to SO3 by Gas-Phase Organic Oxidants. J. Phys. Chem. A 2011, 115, 8669-8681. (22) Long, B.; Tan, X. F.; Long, Z. W.; Wang, Y. B.; Ren, D. S.; Zhang, W. J. Theoretical Studies on Reactions of the Stabilized H2COO with HO2 and the HO2...H2O Complex. J. Phys. Chem. A 2011, 115, 6559-6567. (23) Vereecken, L.; Harder, H.; Novelli, A. The Reaction of Criegee Intermediates with NO, RO2, and SO2, and Their Fate in the Atmosphere. Phys. Chem. Chem. Phys. 2012, 14, 14682-14695. (24) Berndt, T.; Kaethner, R.; Voigtlander, J.; Stratmann, F.; Pfeifle, M.; Reichle, P.; Sipila, M.; Kulmala, M.; Olzmann, M. Kinetics of the Unimolecular Reaction of CH2OO and the Bimolecular Reactions with the Water Monomer, Acetaldehyde and Acetone under Atmospheric Conditions. Phys. Chem. Chem. Phys. 2015, 17, 19862-19873. (25) Kuwata, K. T.; Guinn, E. J.; Hermes, M. R.; Fernandez, J. A.; Mathison, J. M.; Huang, K. A Computational Re-Examination of the Criegee Intermediate-Sulfur Dioxide Reaction. J. Phys. Chem. A 2015, 119, 10316-10335. (26) Vereecken, L.; Rickard, A. R.; Newland, M. J.; Bloss, W. J. Theoretical Study of the Reactions of Criegee Intermediates with Ozone, Alkylhydroperoxides, and Carbon Monoxide. Phys. Chem. Chem. Phys. 2015, 17, 23847-23858. (27) Chen, L.; Huang, Y.; Xue, Y.; Cao, J.; Wang, W. Competition between HO2 and H2O2 Reactions with CH2OO/antiCH3CHOO in the Oligomer Formation: A Theoretical Perspective. J. Phys. Chem. A 2017, 121, 6981-6991. (28) Vereecken, L.; Nguyen, H. M. T. Theoretical Study of the Reaction of Carbonyl Oxide with Nitrogen Dioxide: CH2OO + NO2. Int. J. Chem. Kinet. 2017, 49, 752-760. (29) Xu, K.; Wang, W.; Wei, W.; Feng, W.; Sun, Q.; Li, P. Insights into the Reaction Mechanism of Criegee Intermediate CH2OO with Methane and Implications for the Formation of Methanol. J. Phys. Chem. A 2017, 121, 7236-7245. (30) Zhao, Q.; Liu, F.; Wang, W.; Li, C.; Lu, J.; Wang, W. Reactions between Hydroxyl-Substituted Alkylperoxy Radicals and Criegee Intermediates: Correlations of the Electronic Characteristics of Methyl Substituents and the Reactivity. Phys. Chem. Chem. Phys. 2017, 19, 15073-15083. (31) Raghunath, P.; Lee, Y. P.; Lin, M. C. Computational Chemical Kinetics for the Reaction of Criegee Intermediate CH2OO with HNO3 and Its Catalytic Conversion to OH and HCO. J. Phys. Chem. A 2017, 121, 3871-3878. (32) Horie, O.; Schafer, C.; Moortgat, G. K. High Reactivity of Hexafluoro Acetone toward Criegee Intermediates in the Gas-Phase Ozonolysis of Simple Alkenes. Int. J. Chem. Kinet. 1999, 31, 261-269.

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(33) Crehuet, R.; Anglada, J. M.; Cremer, D.; Bofill, J. M. Reaction Modes of Carbonyl Oxide, Dioxirane, and Methylenebis(oxy) with Ethylene: A New Reaction Mechanism. J. Phys. Chem. A 2002, 106, 3917-3929. (34) Tuazon, E. C.; Alvarado, A.; Aschmann, S. M.; Atkinson, R.; Arey, J. Products of the Gas-Phase Reactions of 1,3-Butadiene with OH and NO3 Radicals. Environ. Sci. Technol. 1999, 33, 3586-3595. (35) Berndt, T.; Boge, O. Atmospheric Reaction of Oh Radicals with 1,3-Butadiene and 4-Hydroxy-2-Butenal. J. Phys. Chem. A 2007, 111, 12099-12105. (36) Eskola, A. J.; Dontgen, M.; Rotavera, B.; Caravan, R. L.; Welz, O.; Savee, J. D.; Osborn, D. L.; Shallcross, D. E.; Percival, C. J.; Taatjes, C. A. Direct Kinetics Study of CH2OO + Methyl Vinyl Ketone and CH2OO + Methacrolein Reactions and an Upper Limit Determination for CH2OO + CO Reaction. Phys. Chem. Chem. Phys. 2018, 20, 19373-19381. (37) Nakajima, M.; Endo, Y. Communication: Determination of the Molecular Structure of the Simplest Criegee Intermediate CH2OO. J. Chem. Phys. 2013, 139, 101103. (38) Su, Y. T.; Huang, Y. H.; Witek, H. A.; Lee, Y. P. Infrared Absorption Spectrum of the Simplest Criegee Intermediate CH2OO. Science 2013, 340, 174-176. (39) Kumar, M.; Busch, D. H.; Subramaniam, B.; Thompson, W. H. Criegee Intermediate Reaction with CO: Mechanism, Barriers, Conformer-Dependence, and Implications for Ozonolysis Chemistry. J. Phys. Chem. A 2014, 118, 1887-1894. (40) Aplincourt, P.; Ruiz-López, M. F. Theoretical Investigation of Reaction Mechanisms for Carboxylic Acid Formation in the Atmosphere. J. Am. Chem. Soc. 2000, 122, 8990-8997. (41) Ryzhkov, A. B.; Ariya, P. A. A Theoretical Study of the Reactions of Parent and Substituted Criegee Intermediates with Water and the Water Dimer. Phys. Chem. Chem. Phys. 2004, 6, 5042-5050. (42) Cabezas, C.; Endo, Y. Spectroscopic Characterization of the Reaction Products between the Criegee Intermediate CH2OO and HCl. ChemPhysChem 2017, 18, 1860-1863. (43) Jorgensen, S.; Gross, A. Theoretical Investigation of the Reaction between Carbonyl Oxides and Ammonia. J. Phys. Chem. A 2009, 113, 10284-10290. (44) Misiewicz, J. P.; Elliott, S. N.; Moore, K. B.; Schaefer, H. F. Re-Examining Ammonia Addition to the Criegee Intermediate: Converging to Chemical Accuracy. Phys. Chem. Chem. Phys. 2018, 20, 7479-7491. (45) Zhao, Y.; Truhlar, D. G. The M06 Suite of Density Functionals for Main Group Thermochemistry, Thermochemical Kinetics, Noncovalent Interactions, Excited States, and Transition Elements: Two New Functionals and Systematic Testing of Four M06-Class Functionals and 12 Other Functionals. Theor. Chem. Acc. 2008, 120, 215-241. (46) Piletic, I. R.; Edney, E. O.; Bartolotti, L. J. A Computational Study of Acid Catalyzed Aerosol Reactions of Atmospherically Relevant Epoxides. Phys. Chem. Chem. Phys. 2013, 15, 18065. (47) Balaganesh, M.; Dash, M. R.; Rajakumar, B. Experimental and Computational Investigation on the Gas Phase Reaction of Ethyl Formate with Cl Atoms. J. Phys. Chem. A 2014, 118, 5272-5278. (48) Srinivasulu, G.; Rajakumar, B. Gas Phase Kinetics of 2,2,2-Trifluoroethylbutyrate with the Cl Atom: An Experimental and Theoretical Study. J. Phys. Chem. A 2015, 119, 9294-9306. (49) Miller, J. A.; Klippenstein, S. J. From the Multiple-Well Master Equation to Phenomenological Rate Coefficients: Reactions on a C3H4 Potential Energy Surface. J. Phys. Chem. A 2003, 107, 2680-2692. (50) Sun, C. H.; Xu, B. E.; Zhang, S. W. Atmospheric Reaction of Cl Plus Methacrolein: A Theoretical Study on the Mechanism, and Pressure- and Temperature-Dependent Rate Constants. J. Phys. Chem. A 2014, 118,

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3541-3551. (51) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A. et al. Gaussian 09, Revision B.01; Gaussian, Inc.: Wallingford, CT, 2010. (52) Gilbert, R. G.; Smith, S. C. Theory of Unimolecular and Recombination Reactions; Blackwell Scientific: Carlton, Australia, 1990. (53) Holbrook, K. A.; Michael J. Pilling; Robertson, S. H. Unimolecular Reactions, 2nd ed.; Wiley: New York, 1996. (54) Klippenstein, S. J.; Harding, L. B. A Summary of "a Direct Transition State Theory Based Study of Methyl Radical Recombination Kinetics". J. Phys. Chem. A 2000, 104, 2351-2354. (55) Huynh, L. K.; Zhang, H. R.; Zhang, S.; Eddings, E.; Sarofim, A.; Law, M. E.; Westmoreland, P. R.; Truong, T. N. Kinetics of Enol Formation from Reaction of OH with Propene. J. Phys. Chem. A 2009, 113, 3177-3185. (56) Glowacki, D. R.; Pilling, M. J. Unimolecular Reactions of Peroxy Radicals in Atmospheric Chemistry and Combustion. ChemPhysChem 2010, 11, 3836-3843. (57) da Silva, G. Reaction of Methacrolein with the Hydroxyl Radical in Air: Incorporation of Secondary O2 Addition into the MACR + OH Master Equation. J. Phys. Chem. A 2012, 116, 5317-5324. (58) Chandler, D. W.; Miller, J. A. A Theoretical Analysis of Photoactivated Unimolecular Dissociation: The Overtone Dissociation of Tbutyl Hydroperoxide. J. Chem. Phys. 1984, 81, 455-464. (59) Miller, J. A.; Chandler, D. W. A Theoretical Analysis of the Overtone-Induced Isomerization of Methyl Isocyanide. J. Chem. Phys. 1986, 85, 4502-4508. (60) Miller, J. A.; Klippenstein, S. J. Master Equation Methods in Gas Phase Chemical Kinetics. J. Phys. Chem. A 2006, 110, 10528-10544. (61) Miller, J. A.; Klippenstein, S. J.; Robertson, S. H. A Theoretical Analysis of the Reaction between Vinyl and Acetylene: Quantum Chemistry and Solution of the Master Equation. J. Phys. Chem. A 2000, 104, 7525-7536. (62) Huynh, L. K.; Zhang, H. R.; Zhang, S.; Eddings, E.; Sarofim, A.; Law, M. E.; Westmoreland, P. R.; Truong, T. N. Kinetics of Enol Formation from Reaction of OH with Propene. J. Phys. Chem. A 2009, 113, 3177-3185. (63) Duncan, W. T.; Bell, R. L.; Truong, T. N. Therate: Program Forab Initio Direct Dynamics Calculations of Thermal and Vibrational-State-Selected Rate Constants. J. Comput. Chem. 1998, 19, 1039-1052. (64) Bader, R. F. W. Atoms in Molecules - a Quantum Theory; Oxford University Press: Oxford, 1990. (65) Bader, R. F. W. A Quantum Theory of Molecular Structure and Its Applications. Chem. Rev. 1991, 91, 893-928. (66) Zeng, Y.; Zheng, S.; Meng, L. Studies on Reactions INCX → IXCN (X = O, S, and Se). Inorg. Chem. 2004, 43, 5311-5320. (67) Anglada, J. M.; Domingo, V. M. Mechanism for the Gas-Phase Reaction between Formaldehyde and Hydroperoxyl Radical. A Theoretical Study. J. Phys. Chem. A 2005, 109, 10786-10794. (68) Hermans, I.; Nguyen, T. L.; Jacobs, P. A.; Peeters, J. Tropopause Chemistry Revisited: HO2*-Initiated Oxidation as an Efficient Acetone Sink. J. Am. Chem. Soc. 2004, 126, 9908-9909. (69) Sun, C.; Zeng, Y.; Xu, B.; Meng, L. Mechanism and Kinetics for the Reactions of Methacrolein and Methyl Vinyl Ketone with HO2 Radical. New J. Chem. 2017, 41, 7714-7722.

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TOC Graphic

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Scheme 1. The formation of Criegee intermediates from alkene ozonolysis, where R represents H atom or any alkyl substituent. 23x6mm (600 x 600 DPI)

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Figure 1. Molecular graphs of the reaction complexes. Bond critical points are shown as small red spherea and ring critical points are shown as small yellow spherea. 104x68mm (300 x 300 DPI)

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Figure 2. Calculated mechanism and optimized geometries of the intermediates, transition states, and products. (A) Addition reaction to C=O bond; (B) Addition reaction to C=C bond. 86x46mm (300 x 300 DPI)

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Figure 2. Calculated mechanism and optimized geometries of the intermediates, transition states, and products. (A) Addition reaction to C=O bond; (B) Addition reaction to C=C bond. 103x67mm (300 x 300 DPI)

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Figure 3. HL// M06-2X/aug-cc-pVTZ potential energy surfaces (including zero-point corrections) for CH2OO + acrolein (omitting the biradical intermediates in Figure 3b), the total energy of the reactants is set as zero for reference, and the relative energies are given in kcal mol−1. (A) Addition reaction to the C=O bond; (B) Addition reaction to the C=C bond; (C) Insertion reaction of the terminal oxygen atom to the C-H bonds; (D) Insertion reaction of CH2OO itself to the C-H bonds. 60x45mm (600 x 600 DPI)

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Figure 3. HL// M06-2X/aug-cc-pVTZ potential energy surfaces (including zero-point corrections) for CH2OO + acrolein (omitting the biradical intermediates in Figure 3b), the total energy of the reactants is set as zero for reference, and the relative energies are given in kcal mol−1. (A) Addition reaction to the C=O bond; (B) Addition reaction to the C=C bond; (C) Insertion reaction of the terminal oxygen atom to the C-H bonds; (D) Insertion reaction of CH2OO itself to the C-H bonds. 60x45mm (600 x 600 DPI)

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Figure 3. HL// M06-2X/aug-cc-pVTZ potential energy surfaces (including zero-point corrections) for CH2OO + acrolein (omitting the biradical intermediates in Figure 3b), the total energy of the reactants is set as zero for reference, and the relative energies are given in kcal mol−1. (A) Addition reaction to the C=O bond; (B) Addition reaction to the C=C bond; (C) Insertion reaction of the terminal oxygen atom to the C-H bonds; (D) Insertion reaction of CH2OO itself to the C-H bonds. 66x55mm (600 x 600 DPI)

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Figure 3. HL// M06-2X/aug-cc-pVTZ potential energy surfaces (including zero-point corrections) for CH2OO + acrolein (omitting the biradical intermediates in Figure 3b), the total energy of the reactants is set as zero for reference, and the relative energies are given in kcal mol−1. (A) Addition reaction to the C=O bond; (B) Addition reaction to the C=C bond; (C) Insertion reaction of the terminal oxygen atom to the C-H bonds; (D) Insertion reaction of CH2OO itself to the C-H bonds. 60x46mm (600 x 600 DPI)

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The Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 4. The overall rate constants of CH2OO + acrolein reaction at the temperature range of 200-500 K. 60x46mm (600 x 600 DPI)

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Figure 5. The products branching ratio at the pressure range of 1-760 Torr. 60x45mm (600 x 600 DPI)

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TOC Graphic 59x44mm (600 x 600 DPI)

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