Reaction of Stabilized Criegee Intermediates from Ozonolysis of

12452

J. Phys. Chem. A 2010, 114, 12452–12461

Reaction of Stabilized Criegee Intermediates from Ozonolysis of Limonene with Sulfur Dioxide: Ab Initio and DFT Study Lei Jiang,†,‡ Yi-sheng Xu,*,† and Ai-zhong Ding‡ Atmospheric Chemistry and Aerosol Research DiVision, Chinese Research Academy of EnVironmental Science, Beijing 100012, China, College of Water Sciences, Beijing Normal UniVersity, Beijing 100875, China ReceiVed: August 17, 2010; ReVised Manuscript ReceiVed: October 21, 2010

The mechanism of the reaction of the sulfur dioxide (SO2) with four stabilized Criegee intermediates (stabCI-CH3-OO, stabCI-OO, stabCIx-OO, and stabCH2OO) produced via the ozonolysis of limonene have been investigated using ab initio and DFT (density functional theory) methods. It has been shown that the intermediate adduct formed by the initiation of these reactions may be followed by two different reaction pathways such as H migration reaction to form carboxylic acids and rearrangement of oxygen to produce the sulfur trioxide (SO3) from the terminal oxygen of the COO group and SO2. We found that the reaction of stabCI-OO and stabCH2OO with SO2 can occur via both the aforementioned scenarios, whereas that of stabCI-CH3-OO and stabCIx-OO with SO2 is limited to the second pathway only due to the absence of migrating H atoms. It has been shown that at the CCSD(T)/6-31G(d) + CF level of theory the activation energies of six reaction pathways are in the range of 14.18-22.59 kcal mol-1, with the reaction between stabCIx-OO and SO2 as the most favorable pathway of 14.18 kcal mol-1 activation energy and that the reaction of stabCI-OO and stabCH2OO with SO2 occurs mainly via the second reaction path. The thermochemical analysis of the reaction between SO2 and stabilized Criegee intermediates indicates that the reaction of SO2 and stabilized Criegee intermediates formed from the exocyclic primary ozonide decomposition is the main pathway of the SO3 formation. This is likely to explain the large (∼100%) difference in the production rate in the favor of the exocyclic compounds observed in recent experiments on the formation of H2SO4 from exocyclic and endocyclic compounds. 1. Introduction The effect of atmospheric aerosol particles on the Earth’s climate is unambiguous. The aerosol particles influence Earth’s climateindirectlybymodifyingcloudpropertiesandprecipitation.1-4 The aforementioned indirect effect is a main source of uncertainties in the assessment of climate changes. The critical importance of the clear and insightful understanding of the new particle formation is obvious. The new particle formation is an important source of atmospheric aerosols, which is closely connected to a number of micro- and nanoscale processes leading to the gas-to-particle conversion6-9 and formation of viable critical embryos via nucleation. Nucleation in the Earth’s atmosphere is essentially multicomponent and can be described as a H2SO4-H2O-X process, where X refers to NH3 (ternary homogeneous nucleation (THN)10,11), ions (ion mediated nucleation (IMN))5,6,15,16), organics (organic enhanced nucleation17-21) or nothing (binary homogeneous nucleation (BHN)22). Although the key role of the sulfuric acid, the principle atmospheric nucleation precursor, in the secondary particle formation is undisputable, X remains a subject of ongoing debates despite decades of intensive experimental and theoretical studies. The pioneering experimental work of Zhang et al.17 has shown that organic species can enhance and can play a significant role in the atmospheric nucleation involving sulfuric acid and water. More recently, Nadykto and Yu18 found that low-molecular carboxylic acids, which are among the most abundant organic * To whom correspondence should be addressed. Phone: 0086-1084915249. Fax: 0086-10-84915248. E-mail: [email protected]. † Chinese Research Academy of Environmental Science. ‡ Beijing Normal University.

acids in the atmosphere, to be able to stabilize atmospheric prenucleation clusters. A number of recent observations23-30 and quantum-chemical investigations18-22 give us a clear indication of the involvement of organic species in the secondary aerosol formation. Although both binary and ternary atmospheric clusters and the impact of organics on their thermochemical stability have been studied in some detail in the past,31-35,12,18-22 only a few studies considering the contribution of organic species to the secondary aerosol formation via chemical reactions are available in the literature.36 Atmospheric photochemical oxidation of nonmethane volatile organic chemicals (VOCs) emitted into the Earth’s atmosphere from both biogenic and anthropogenic sources37 is an important source of secondary organic aerosol (SOA). Gas-phase reactions with ozone are important for the loss of alkenes,38,39 in the atmosphere leading to the production of HO, HO2, RO2 radicals, and organic peroxides, and they play a major role in the oxidative potential of the atmosphere.40-42 Ozonolysis of alkenes occurring via Criegee intermediate (carbonyl oxide) formation was first detected in the liquid phase.43 Later, its relevance to the gas-phase processes in the atmosphere was demonstrated.44,45 The excited Criegee intermediate formed from cleavage of the primary ozonide can be stabilized collisionally. The stabilized Criegee intermediates can react with various atmospheric compounds,44,46-49 particularly formaldehyde, H2O, NOX, SO2, H2SO4, CO, and many others. Recently, Kurteń et al.50 reported the reactions of five stabilized Criegee intermediates with sulfuric acid and water using quantum chemical methods. Theoretical results showed that the reaction of stabilized Criegee intermediates with sulfuric acid should proceed significantly

10.1021/jp107783z  2010 American Chemical Society Published on Web 11/05/2010

Reaction of Criegee Intermediates with SO2

J. Phys. Chem. A, Vol. 114, No. 47, 2010 12453

SCHEME 1: Limonene + O3 Reaction Pathway for Stabilized Criegee Intermediates Yields (Taken from Leungsakulet al., 200558)

faster than the reaction with water, and both reactions were strongly exothermic for all studied species. The study also showed that if a significant fraction of biogenic stabilized Criegee intermediates lived long enough for bimolecular reactions, then the reaction between stabilized Criegee intermediates and sulfuric acid may play an important role in the atmosphere. One of the most important reactions in atmosphere is the reaction of Criegee intermediates with the sulfur dioxide. This reaction has been experimentally studied in the 1980s due to its possible contribution to the rain acidity via the formation of H2SO4,51 which is the key atmospheric nucleation precursor and one of the major constituents of acid rains. It is important to note that the oxidation of SO2 by Criegee intermediates is likely to play a considerable role in the secondary aerosol formation.52 Calvert and Stockwell53 pointed out that in the highly polluted conditions the reaction of the Criegee intermediates can make a significant (up to 50%) contribution to the SO2 oxidation at low humidity. Being produced by more than 300 species, limonene or 4-isopropenyl-1-methyl-cyclohexene, is the most abundant monoterpene.54,55 The reaction of ozone with limonene, which has both endocyclic and exocyclic double bonds, is an important oxidation process in the troposphere. Ozonolysis of limonene is an important source of OH radicals and can also play a significant role in the formation of acid rains and atmospheric aerosols via the oxidation of SO2 by carbonyl oxides.52 Ozonolysis of limonene is a complex process involving a

number of reactions and intermediates. Limonene + O3 reaction pathway for the stabilized Criegee intermediates yields is shown in Scheme 1. As it may be seen from Scheme 1, the two CIs resulting from the O3 attraction of the cyclo double bond of limonene are called CI-CH3-OO* (among 0.65) and CI-OO* (among 0.35), which then form stabilized CI-CH3-OO (stabCI-CH3-OO) and stabilized CI-OO (stabCI-OO) via the collisionally stabilized among 0.20 CI-CH3-OO* and 0.50 CI-OO*. Two other CIs formed from O3 attack on the external carbon bond of limonene are CIx-OO* (among 0.68) and CH2OO*56,57 (among 0.32). Then among 0.35 CIx-OO* and 0.40 CH2OO* are also formed stabilized CIx-OO (stabCIx-OO) andstabilizedCH2OO(stabCH2OO)viathecollisionalstabilization.58,59 Experimental and theoretical studies of the reaction of SO2 with the stabilized Criegee intermediates from ozonolysis of alkenes indicate that the formation of a five-membered ring intermediate adduct is followed by the decomposition via two different reaction pathways.52,60-65 An intermediate adduct with a five-membered ring is formed by the addition of the sulfur dioxide molecule to the stabilized Criegee intermediate. Then, the intermediate adduct could follow one of or both of two different reaction pathways via the following corresponding transition states: (a) In the case where the S-O bond of sulfur dioxide is broken, the oxygen atom of sulfur dioxide is bonded to the carbon atom of the stabilized Criegee intermediate, forming the CdO double bond and SO moiety. The broken

12454

J. Phys. Chem. A, Vol. 114, No. 47, 2010

Jiang et al.

SCHEME 2: Mechanistic Diagrams for the Reactions of SO2 and Stabilized Criegee Intermediates Arising from the Limonene Ozonolysis

peroxide OO bond of the COO group belonging to the stabilized Criegee intermediate forms the O atom and CO group, while the O atom migration toward the SO moiety leads to the formation of the sulfur dioxide molecule via recombination. Meanwhile, hydrogen the atom belonging to the stabilized Criegee intermediate is getting transferred to the terminal oxygen of the CO group; (b) the peroxide OO bond of the COO group belonging to the stabilized Criegee intermediate is broken first, and, then, the terminal oxygen of the COO group moves toward the sulfur dioxide molecule, forming CdO double bond of the stabilized Criegee intermediate and the sulfur trioxide molecule. The mechanistic diagrams for the reactions of the stabilized Criegee intermediates and SO2 are shown in Scheme 2. The structures of the intermediate adduct and transition states are represented by the letters M and TS, respectively. The M1 and M4 follow the two reaction pathways via their corresponding transition states (TS11, TS12, TS41, and TS42), producing limononic acid, limononaldehyde, formic acid, formaldehyde, SO2, and SO3. M2 and M3 follow the second reaction pathways via their corresponding transition states (TS2 and TS3), producing limononaldehyde, keto-limonene, and SO3.

Although it is well-known that the role of the reaction between Criegee intermediates from ozonolysis of limonene and SO2 is very important for the formation of atmospheric organics aerosols, the mechanism of these reactions remains poorly understood. Because the stability of the Criegee intermediates is moderately weak, theoretical calculations are very useful for determining the geometric and electronic structures of these compounds. In the present paper, the reaction of SO2 with four stabilized Criegee intermediates (stabCI-CH3-OO, stabCI-OO, stabCIx-OO, and stabCH2OO) from ozonolysis of limonene has been investigated, and the oxidation mechanism has been studied in detail. Ab initio and DFT methods have been employed to obtain geometries and energies of the transition states and subsequent formation of products. Reaction and activation energies, enthalpies, and free energies for the reaction between stabilized Criegee intermediates and SO2 have been obtained at different levels of theory, including the higher level CCSD(T)/6-31G(d) + CF. In addition, for the HCOOH formation from reaction of stabCH2OO with SO2, the HC18OOH formation mechanism (H-transfer to the O atom bonded simultaneously to C and S atoms in the five-membered ring)

Reaction of Criegee Intermediates with SO2 has been verified in our theoretical study that was carried out using the MP2/6-31G(d,p) method. 2. Computational Details The theoretical computations were performed with the SGI ALTIX 4700 supercomputer using Gaussian 03 suite of programs.66 The geometry optimization of all reactants, stabilized Criegee intermediates, transition states, and products was executed using Becke’s three-parameter hybrid method employing the LYP correction function (B3LYP) in conjunction with the split valence polarized basis set 6-31G(d,p) with harmonic vibrational frequencies analyses.67,68 The stationary points are classified as minima in the case, when no imaginary frequencies are found, and as a transition state if only one imaginary frequency is obtained. To ensure that the transition states connect reactants and products, the intrinsic reaction coordinate (IRC) method69 at the B3LYP/6-31G(d,p) level of theory has been applied to each transition state of every reaction. The DFT structures were then used in the single-point energy calculations using frozen core second-order Møller-Plesset perturbation theory (MP2) and coupled-cluster theory with single and double excitations including perturbative corrections for the triple excitations (CCSD(T)70 with various basis sets. The basis set effects on calculated energies for the reactions of stabilized Criegee intermediates with SO2 and were corrected at MP2 level according to the recently developed method, which has been successfully applied for studying the complex reaction mechanisms and pathways of volatile organic compounds (VOCs) in the atmosphere.71 A correction factor (CF) has been determined from the energy difference between the MP2/6-31G(d) and MP2/6-311++G(d,p) levels. Energies calculated at the CCSD(T)/6-31G(d) level of theory have been corrected using the aforementioned MP2 level corrections This method has been validated in several studies of isoprene and limonene reactions initiated by NO3, OH, and O3.71-75 Density functional theory has been widely employed for reactions of VOCs with ozone or OH radical and description of the Criegee intermediates in the VOCs ozonolysis reaction.76-83 These studies indicate that the optimized geometries of Criegee intermediates and description of unimolecular reaction at the B3LYP level agree well with those obtained at the CCSD(T) level; therefore, DFT B3LYP is an appropriate method for studying the ozonolysis reactions. 3. Results and Discussion 3.1. Reaction of Limonene Stabilized Criegee Intermediates with SO2. The reaction between SO2 and limonene stabilized Criegee intermediates proceeds via six reaction pathways such as the reactions between SO2 and stabCI-OO and stabCI-CH3-OO formed from the endocyclic primary ozonide decomposition (TS11, TS12, and TS2; see Scheme 2) and between SO2 and stabCIx-OO and stabCH2OO formed from the exocyclic primary ozonide decomposition (TS3, TS41, and TS42; see Scheme 2). Each transition state has only one imaginary harmonic vibrational frequency and can be classified as the first-order saddle point. The values of imaginary frequencies for TS11, TS12, TS2, TS3, TS41, and TS42 transition states are 671.40i, 510.93i, 533.74i, 448.63i, 845.02i, and 447.54i, respectively. a. Reaction Mechanism. Figure 1 presents the optimized geometries of the stationary points for the reaction of stabCI-OO and SO2 obtained at the B3LYP/6-31G(d,p) level of theory and values of the most important geometrical properties. The reactions of stabCI-OO with SO2 first lead to formation of an

J. Phys. Chem. A, Vol. 114, No. 47, 2010 12455 intermediate adduct M1. Then the M1 evolves via the transition state TS11 [the H migration path or reaction (a)], to the limononic acid and SO2. As seen from Figure 1, the intermediate adduct (M1) has a five-membered ring. The length of the C1-O6 bond, in which the oxygen (O6) of the original sulfur dioxide is connected to the carbon atom (C1), is 1.449 Å, and the distance of the O6-S7 bond belonging to the sulfur dioxide is 1.680 Å. The length of the O4-S7 bond, where the terminal oxygen atom (O4) of the COO group belonging to stabCI-OO is connected to the sulfur atom (S7), is 1.760 Å. Compared to the stabCI-OO, both the peroxide O3-O4 bond (1.446 Å) and C1-O3 bond (1.418 Å) of the C1-O3-O4 group for M1 are elongated by 0.082 and 0.145 Å, respectively. The C1-H2 bond (1.092 Å) is 0.004 Å longer than stabCI-OO. A comparison of the corresponding transition (TS11) structure with M1 intermediate shows that the distance of C1-O6 bond decreases to 1.335 Å, whereas the O6-S7 distance increases by 0.342 Å to 2.022 Å. The O4-S7 bond decreases by 0.237 Å, reaching 1.523 Å. The peroxide O3-O4 distance is elongated by 0.570 Å, reaching 2.016 Å, whereas the C1-O3 bond decreases to 1.333 Å. The C1-H2 bond (1.170 Å) increases by 0.078 Å. Although both O3-O4 and O6-S7 bonds are broken, and O3-O4 and O6-S7 distances continue to increase, the H2 atom is getting transferred to the O3 atom, and a double C1-O6 bond is forming. The C1-O3, C1-O6 and O3-H2 bonds in limononic acid are 1.356, 1.208, and 0.975 Å, respectively. M1 can also evolve via the transition state TS12 [the formed sulfur trioxide process or reaction (b)], into the limononaldehyde and SO3. In this case, in the corresponding transition (TS12) structure, the C1-O6 distance (1.700 Å) is increased by 0.251 Å, O4-S7 (1.512 Å) is enlarged by 0.248 Å, and O6-S7 (1.581 Å) is decreased by 0.099 Å compared with M1. The O3-O4 distance is elongated by 0.583 Å, reaching 2.029 Å, whereas the C1-O3 bond decreases to 1.287 Å. The C1H2 bond (1.095 Å) remains virtually unchanged. The O3-O4 and C1-O6 bonds are broken, and their lengths continue to grow, while the terminal O4 of the C1-O3-O4 group moves toward the sulfur dioxide molecule, forming the double bond C1dO3 (1.213 Å). Scheme 2 and Figure 1 show that the reaction of stabCI-CH3-OO and stabCIx-OO with SO2 follows the same trends as those for the (b) reaction. The reacting stabCI-CH3-OO and SO2 evolve via the transition state TS2 to form the limononaldehyde and SO3, whereas stabCIx-OO transforms via the TS3 to keto-limonene and SO3. Scheme 2 and Figure 1 also reveal that the reaction between stabCH2OO and SO2 follows the same pattern and schematized above for the reaction of stabCI-OO and SO2. It evolves via the transition states TS41 [reaction (a)] and TS42 [reaction (b)] to formic acid (HCOOH), formaldehyde (HCHO), SO2, and SO3. b. Thermochemical Analysis. Reaction and activation energies for the reaction between stabilized Criegee intermediates and SO2 with the zero-point correction (ZPE) included were calculated at different levels of theory. The results of the calculations are presented in Table 1. As it may be seen from Table 1, the difference between the reaction and activation energies calculated at different levels of theory is considerable. The values predicted by B3LYP/6-31G(d,p) and CCSD(T)/631G(d) are close and agree within 2.28 kcal mol-1; however, they are higher than those obtained using MP2. The MP2 values obtained using different basis sets differ by -5.4 to 5.86 kcal mol-1. At the B3LYP/6-31G(d,p) level of theory, the products are 54.33-112.67 kcal mol-1 more stable than the separate stabilized Criegee intermediates and SO2. The activation energies

12456


Jiang et al.

Figure 1. Geometries of stationary points involved in the limonene stabilized Criegee intermediates + SO2 reaction obtained at B3LYP/6-31G(d,p) level. Bond distances are given in Å.

TABLE 1: Reaction and Activation Energies (E) with Zero-Point Correction (ZPE) Included (kcal mol-1) at Different Levels of Theory for the Reaction between Limonene Stabilized Criegee Intermediates and SO2a compound stabCl-OO + SO2 M1 TS11 TS12 limononic acid + SO2 limononaldehyde + SO3 stabCl-CH3-OO + SO2 M2 TS2 limononaldehyde + SO3 stabClx-OO + SO2 M3 TS3 keto-limonene + SO3 stabCH2OO + SO2 M4 TS41 TS42 HCOOH + SO2 HCHO + SO3 a

relative to stabCl-OO + SO2 M1 M1 stabCl-OO + SO2 stabCl-OO + SO2 stabCl-CH3-OO + SO2 M2 stabCl-CH3-OO + SO2 stabClx-OO + SO2 M3 stabClx-OO + SO2 stabCH2OO + SO2 M4 M4 stabCH2OO + SO2 stabCH2OO + SO2

H(B3LYP/ 6-31G(d,p))

H(MP2/6-31G(d))

H(MP2/6-311 ++G(d,p))

H(CCSD(T)/ 6-31G(d))

H(CCSD(T)/6-31G (d) + CF)

0.00 -28.56 24.41 17.46 -106.56 -56.54 0.00 -26.48 19.24 -54.34 0.00 -27.59 17.39 -55.94 0.00 -37.03 27.53 17.85 -112.67 -59.33

0.00 -33.65 28.55 5.04 -117.79 -69.49 0.00 -32.77 10.23 -65.09 0.00 -35.42 1.93 -67.99 0.00 -39.00 31.31 4.41 -123.83 -72.46

0.00 -29.21 23.95 3.18 -123.65 -66.04 0.00 -25.48 8.85 -59.69 0.00 -28.63 -0.85 -63.49 0.00 -31.36 25.70 2.96 -128.18 -68.69

0.00 -31.27 25.52 17.29 -107.96 -58.82 0.00 -29.72 19.40 -54.44 0.00 -32.49 16.96 -57.60 0.00 -35.60 28.20 16.70 -113.21 -61.08

0.00 -26.82 20.91 15.43 -113.82 -55.37 0.00 -22.44 18.03 -49.04 0.00 -25.71 14.18 -53.10 0.00 -27.96 22.59 15.26 -117.56 -57.31

refb

0.00 -35.20 23.60 -115.00

Optimized geometries, vibrational frequencies and ZPE obtained at the B3LYP/6-31G(d,p) level. b B3LYP/6-31G(d,p)// B3LYP/6-31G(d,p) study, ref 65.



Figure 2. Limonene stabilized Criegee intermediates + SO2 reaction coordinates: relative energies of the stationary points located on the initial intermediate adduct M ground-state potential energy surface. The energy values are given in kcal mol-1 and are calculated using CCSD(T)/631G(d) + CF//B3LYP/6-31G(d,p) level.

with respect to the initial intermediate adduct M are in the range of 17.39-27.53 kcal mol-1. The B3LYP/6-31G(d,p) reaction energy and activation energy with respect to M4 are 112.67 and 27.53 kcal mol-1 for the reaction (a) of stabCH2OO and SO2. They are in excellent agreement with the previous theoretical study of the reaction between stabCH2OO and SO2 (115.00 and 23.60 kcal mol-1).65 The higher level CCSD(T)/6-31G(d) + CF predicts that the initial intermediate adduct M and products are by 22.44-27.96 kcal mol-1 and 49.04-117.56 kcal mol-1 more stable than the separate stabilized Criegee intermediates and SO2, respectively. For the reaction of stabCI-OO and stabCH2OO with SO2, the products formed via the reaction (a) are more stable than those formed via the reaction (b). The activation energies of the six reaction pathways lie in the range of 14.18-22.59 kcal mol-1 with respect to corresponding initial intermediate adduct M, with the reaction between stabCIx-OO and SO2 as the most favorable pathway of the activation energy of 14.18 kcal mol-1. The activation energies for the reaction (b) (14.18 - 18.03 kcal mol-1) are smaller than those for the reaction (a) (20.91 and 22.59 kcal mol-1). This gives us a clear indication that the reaction (b) is more favorable than the reaction (a). The activation energies for reaction (b) of stabCI-OO and stabCH2OO with SO2 (14.18 and 15.26 kcal mol-1) are smaller than those for the same reaction of stabCI-CH3-OO and stabCIx-OO with SO2 (15.43 and 18.03 kcal mol-1). This shows clearly that the reaction between SO2 and stabilized

Criegee intermediates formed from the exocyclic primary ozonide decomposition is more favorable than that formed from the endocyclic primary ozonide decomposition. This is likely to explain the observation of Hatakeyama et al.,61 who found that the yield of H2SO4 from exocyclic compounds is twice as large as that from endocyclic compounds. Figure 2 illustrates the relative energies of the stationary points located on the singlet ground-state the initial intermediate adduct M potential energy surface at the CCSD(T)/6-31G(d) + CF level of theory. Reaction and activation enthalpies for the reaction between stabilized Criegee intermediates and SO2 obtained at different levels of theory with the thermal correction to enthalpy included, are listed in Table 2. As it may be seen from Table 2, the values of reaction and activation enthalpies are in accordance with those of reaction and activation energies. At the CCSD(T)/6-31G(d) + CF level of theory, the reactions between stabilized Criegee intermediates and SO2 are exothermic by 49.18-117.64 kcal mol-1. The computed activation enthalpies are in the range of 14.43-22.99 kcal mol-1 with respect to corresponding initial intermediate adduct M, with the reaction between stabCIx-OO and SO2 as the most favorable reaction of the activation energy of 14.43 kcal mol-1. Reaction and activation Gibbs free energies with the thermal correction for the reaction between stabilized Criegee intermediates and SO2 computed at different levels of theory are shown in Table 3. As seen from Table 3, the values of reaction and activation Gibbs free energies are in accordance with those of

12458


Jiang et al.

TABLE 2: Reaction and Activation Enthalpies (H) with Thermal Correction to Enthalpy Included (kcal mol-1) at Different Levels of Theory for the Reaction between Limonene Stabilized Criegee Intermediates and SO2a compound stabCl-OO + SO2 M1 TS11 TS12 limononic acid + SO2 limononaldehyde + SO3 stabCl-CH3-OO + SO2 M2 TS2 limononaldehyde + SO3 stabClx-OO + SO2 M3 TS3 keto-limonene + SO3 stabCH2OO + SO2 M4 TS41 TS42 HCOOH + SO2 HCHO + SO3 a


H(B3LYP/631G(d,p))

H(MP2/631G(d))

H(MP2/6-311 ++G(d,p))

H(CCSD(T)/ 6-31G(d))

H(CCSD(T)/ 6-31G(d) + CF)

0.00 -29.35 24.67 17.67 -106.60 -56.78 0.00 -27.31 19.35 -54.49 0.00 -28.57 17.65 -56.23 0.00 -38.22 27.93 17.95 -112.75 -59.27

0.00 -34.44 28.81 5.25 -117.83 -69.73 0.00 -33.59 10.34 -65.24 0.00 -36.40 2.18 -68.28 0.00 -40.20 31.71 4.51 -123.90 -72.40

0.00 -30.00 24.21 3.39 -123.69 -66.28 0.00 -26.31 8.97 -59.83 0.00 -29.62 -0.60 -63.78 0.00 -32.56 26.10 3.07 -128.25 -68.63

0.00 -32.06 25.78 17.50 -108.00 -59.06 0.00 -30.55 19.51 -54.59 0.00 -33.48 17.21 -57.89 0.00 -36.79 28.60 16.80 -113.29 -61.02

0.00 -27.61 21.18 15.64 -113.86 -55.61 0.00 -23.26 18.14 -49.18 0.00 -26.69 14.43 -53.39 0.00 -29.15 22.99 15.36 -117.64 -57.25

Optimized geometries and thermal correction to enthalpy obtained at the B3LYP/6-31G(d,p) level.

TABLE 3: Reaction and Activation Gibbs Free Energies (G) with Thermal Correction to Gibbs Free Energy Included (kcal mol-1) at Different Levels of Theory for the Reaction between Limonene Stabilized Criegee Intermediates and SO2a compound stabCl-OO + SO2 M1 TS11 TS12 limononic acid + SO2 limononaldehyde + SO3 stabCl-CH3-OO + SO2 M2 TS2 limononaldehyde + SO3 stabClx-OO + SO2 M3 TS3 keto-limonene + SO3 stabCH2OO + SO2 M4 TS41 TS42 HCOOH + SO2 HCHO + SO3 a


G(B3LYP/631G(d,p))

G(MP2/631G(d))

G(MP2/6-311 ++G(d,p))

G(CCSD(T)/ 6-31G(d))

G(CCSD(T)/ 6-31G(d) + CF)

0.00 -16.27 24.76 17.27 -106.68 -57.35 0.00 -14.59 19.33 -56.26 0.00 -14.73 17.39 -56.47 0.00 -25.15 27.08 17.74 -112.67 -59.23

0.00 -21.36 28.90 4.85 -117.92 -70.31 0.00 -20.87 10.32 -67.01 0.00 -22.56 1.92 -68.52 0.00 -27.12 30.86 4.30 -123.83 -72.35

0.00 -16.92 24.30 2.99 -123.78 -66.86 0.00 -13.58 8.95 -61.60 0.00 -15.77 -0.86 -64.02 0.00 -19.48 25.25 2.86 -128.18 -68.59

0.00 -18.98 25.87 17.10 -108.09 -59.63 0.00 -17.82 19.49 -56.36 0.00 -19.63 16.95 -58.12 0.00 -23.72 27.75 16.59 -113.21 -60.97

0.00 -14.54 21.27 15.24 -113.95 -56.18 0.00 -10.54 18.12 -50.96 0.00 -12.85 14.17 -53.62 0.00 -16.08 22.14 15.15 -117.56 -57.21

Optimized geometries and thermal correction to Gibbs free energy obtained at the B3LYP/6-31G(d,p) level.

reaction and activation energies. At the CCSD(T)/6-31G(d) + CF level of theory, the reaction Gibbs free energies of reaction between stabilized Criegee intermediates and SO2 range from -117.56 to -50.96 kcal mol-1. The strong negativity of Gibbs free energy changes indicate that the reaction of stabilized Criegee intermediates with SO2 is spontaneous. 3.2. Theoretical Verification for the Mechanism to Form HCOOH from the Reaction between stabCH2OO and SO2. In the experiment of gas-phase reaction of SO2 with stabCH2OO, Hatakeyama et al.52 found the reaction mechanism and observed the formation of HC18OOH and HCO18OH in addition to HC18O18OH in the C2H4-18O3-SO2 reaction. The detailed mechanism of HCOOH formation resulted from the reaction of SO2 and stabCH2OO is shown in Scheme 3. As seen from Scheme 3, the reaction of SO2 with stabCH2OO leads first to the formation of a cyclic intermediate adduct. Then, the cyclic intermediate adduct evolves via two reaction pathways to HC18OOH and HCO18OH (named the forming HC18OOH and HCO18OH pathways). The mechanism of HCO18OH formation for the second step has been verified at the B3LYP level in

Aplincourt et al.65 and in the present work. The HC18OOH formation mechanism for the second step, which is the Htransfer to the O atom that bonded simultaneously to both C and S atom in the five-membered ring, did not allow locating the corresponding TS in both the B3LYP study by Aplincourt et al.65 and the present work. However, we succeed to find the corresponding TS for the mechanism of HC18OOH formation at the MP2/6-31G(d,p) level of theory. In the case where the S-O bond of sulfur dioxide is broken, the oxygen of sulfur dioxide bonds to the carbon atom of the stabilized Criegee intermediate leading to the formation of SO moiety. The peroxide O-O bond of the COO group belonging to the stabilized Criegee intermediate is broken, forming the O atom and CO group, while the O atom is migrating toward the SO moiety and recombining with the sulfur dioxide molecule. Meanwhile, a hydrogen atom belonging to the stabilized Criegee intermediate is transferring to the oxygen of sulfur dioxide, which is linked to the carbon atom. The hydrogen atom is transferring to the oxygen atom of the COO group, which is linked to the carbon atom (see Section 3.1.a.).



SCHEME 3: Mechanism of HCOOH Formation via the Reaction of SO2 and stabCH2OO Arising from the Limonene Ozonolysis (Hatakeyama et al., 198615)

The optimized geometries of complexes involved in the formation of HCOOH from reaction of stabCH2OO with SO2 obtained at MP2/6-31G(d) level of theory are shown in Figure 3. The values of imaginary frequency for TSa (the HC18OOH formation pathway) and TSb (the HCO18OH formation pathway) are 521.12i and 1210.35i, respectively. As seen from Figure 3, for the HC18OOH formation reaction, the intermediate adduct (Ma) structure is a five-membered ring. The length of the C1-O5 bond in which the oxygen (O5) of sulfur dioxide links the carbon atom (C1) is 1.437 Å, whereas that of O5-S6 bond belonging to the sulfur dioxide is 1.673 Å. The O3-S6 bond, which the oxygen (O3) of the COO group belonging to stabCH2OO is connected to the sulfur atom (S6), is 1.770 Å. Both the peroxide O2-O3 (1.467 Å) and C1-O2 bonds (1.400 Å) of the COO group are elongated by 0.173 and 0.101 Å, respectively, compared to stabCH2OO. The C1-H4 bond (1.086 Å) increases by 0.011 Å with respect to stabCH2OO. In the corresponding transition (TSa) structure, compared with Ma, the C1-O5 bond decreases to 1.395 Å, whereas the O5-S6 distance decreases by 0.371 Å to 2.044 Å. The O3-S6 bond decreases by 0.288 Å to 1.482 Å. The peroxide O2-O3 distance is elongated by 1.060 Å, reaching 2.527 Å, while the C1-O2

bond decreases to 1.313 Å. The bond length of C1-H4 (1.135 Å) increases by 0.049 Å. The O2-O3 and O5-S6 bonds are broken, and O2-O3 and O5-S6 distances continue to increase, while the H4 atom is transferred to the O5 atom and the C1-O2 double bond is forming. Formic acid and SO2 are formed next. The C1-O2, C1-O5, and O5-H4 bond distances in the formic acid are 1.213, 1.351, and 0.972 Å, respectively. HCO18OH formation reaction pathway follows the same trends as described those for the reaction (a). Reaction and activation energies the HCOOH formation from the reaction between stabCH2OO and SO2 at MP2/6-31G(d,p) level of theory with ZPE are given in Table 4. The activation energies are 19.77 and 26.81 kcal mol-1 for the HC18OOH and HCO18OH formation pathways, respectively. This gives us a clear indication that the HC18OOH formation reaction pathway is more favorable. The initial intermediate adducts are found to be 37.19 and 38.70 kcal mol-1 more stable than the separate stabCH2OO and SO2, respectively. The reaction and activation enthalpies, Gibbs free energies with thermal correction to enthalpy, and thermal correction to Gibbs free energy at MP2/ 6-31G(d,p) level of theory for the HCOOH formation from the reaction between stabCH2OO and SO2 are shown in Table 4.

Figure 3. Geometries of stationary points involved in the formation of HCOOH from the reaction between SO2 and stabCH2OO arising from the limonene ozonolysis obtained at MP2/6-31G(d,p) level. Bond distances are given in Å. TSa and TSb are the transition states for forming HC18OOH and HCO18OH reaction pathway, respectively.

12460


Jiang et al.

TABLE 4: Reaction and Activation Energies, Enthalpies, and Free Energies (E, H, and G) with Zero-Point Correction, Thermal Correction to Enthalpy, and Thermal Correction to Gibbs Free Energy Included (kcal mol-1) at MP2/6-31G(d,p)// MP2/6-31G(d,p) Level of Theory for the Formation of HCOOH via the Reaction between SO2 and stabCH2OO Arising from the Limonene Ozonolysis compound

relative to

Ea

Eb

Ha

Hb

Ga

Gb

stabCH2OO + SO2 M TS HCOOH + SO2

CH2OO + SO2 M CH2OO + SO2

0.00 -37.19 19.77 -124.76

0.00 -38.70 26.81 -124.76

0.00 -38.42 20.37 -124.84

0.00 -39.96 27.07 -124.84

0.00 -25.34 18.74 -124.78

0.00 -26.76 26.59 -124.78

a

HC18OOH formation pathway. b HCO18OH formation pathway.

As it may be seen from Table 4, the difference between reaction and activation enthalpies (H) and reaction and activation Gibbs free energies (G) of the two reaction paths are close to that between the reaction and activation energies (E).

ditional support was provided by the CRAES Supercomputing Facilities. The authors thank Du Jian, Wang Bo, Zhang Zeyan, and Zeng Rui for assisting with the maintenance of the quantum chemical calculations.

4. Conclusions

Supporting Information Available: This material is available free of charge via the Internet at http://pubs.acs.org.

In the present ab initio and DFT study, several important aspects of the gas-phase reaction of the stabilized Criegee intermediates and SO2, which have important implications in the atmospheric physics and chemistry, have been revealed. The present study leads us to the following conclusions: (a) The reaction between the stabilized Criegee intermediates and SO2 initially leads to the formation of a intermediate adduct. Then, the reaction can proceed via two reaction pathways: (a) the H migration path, and (b) the sulfur trioxide formation process, where the terminal oxygen of the COO group migrates toward the sulfur dioxide molecule. The reaction of stabCI-OO and stabCH2OO with SO2 occurs via the two different reaction pathways,whilethereactionofstabCI-CH3-OOandstabCIx-OO with SO2 follows path (b) only. (b) The reaction and activation energies obtained by B3LYP/ 6-31G(d,p) and CCSD(T)/6-31G(d) are close and agree within 2.28 kcal mol-1 for the two reaction pathways. The MP2 values are lower than those of B3LYP/6-31G(d,p) and CCSD(T)/631G(d). (c) The CCSD(T)/6-31G(d) + CF activation energies are in the range of 14.18-22.59 kcal mol-1 with respect to corresponding initial intermediate adduct M. The reaction between stabCIx-OO and SO2 is the most favorable pathway of 14.18 kcal mol-1. For the reaction of stabCI-OO and stabCH2OO with SO2, the reaction and activation energies predicted using CCSD(T)/6-31G(d) + CF indicate that the products formed via reaction (a) are more stable than those formed via reaction (b); however, reaction (b) is a more favorable pathway than reaction (a). (d) The thermochemical analysis of the activation energies calculated using CCSD(T)/6-31G(d) + CF indicate that the reaction between SO2 and stabilized Criegee intermediates formed from the exocyclic primary ozonide decomposition is more favorable than that from the endocyclic primary ozonide decomposition. This conclusion is likely to explain the experimental fact that the yield of H2SO4 from exocyclic compounds is twice as large as that from endocyclic compounds. (e) For the HCOOH formation from reaction of stabCH2OO with SO2, the HC18OOH formation mechanism for the second step is the H-transfer to the O atom bonded simultaneously to C and S atom in the five-membered ring. This reaction mechanism has been verified by theoretical study using MP2/ 6-31G(d,p) and has been found more favorable than the HCO18OH formation. Acknowledgment. This work was supported by National Natural Science Foundation of China (Grant 40975073). Ad-

References and Notes (1) Twomey, S. J. Atmos. Sci. 1977, 34, 1149. (2) Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A.; Hansen, J. E.; Hofmann, D. J. Science 1992, 255, 423. (3) Kulmala, M.; Vehkama¨ki, H.; Peta¨ja¨, T.; Dal Maso, M.; Lauri, A.; Kerminen, V.-M.; Birmili, W.; McMurry, P. H. J. Aerosol Sci. 2004, 35, 143. (4) Arnold, F.; Viggiano, A. A.; Schlager, H. Nature 1982, 297, 371. (5) Yu, F.; Turco, R. P. Geophys. Res. Lett. 2000, 27, 883. (6) Yu, F.; Turco, R. P. J. Geophys. Res. 2001, 106, 479. (7) Nadykto, A. B.; Al Natsheh, A.; Yu, F.; Mikkelsen, K. V.; Ruuskanen, J. Phys. ReV. Lett. 2007, 98, 109604. (8) Nadykto, A. B.; AI Natsheh, A.; Yu, F.; Mikkelsen, K. V.; Ruuskanen, J. Phys. ReV. Lett. 2006, 96, 125701. (9) Du, H.; Nadykto, A. B.; Yu, F. Phys. ReV. E. 2009, 79, 021604. (10) Napari, I.; Noppel, M.; Vehkama¨ki, H.; Kulmala, M. J. Geophys. Res. 2002, 10, 4381. (11) Kim, T. O.; Ishida, T.; Adachi, M.; Okuyama, K.; Seinfeld, J. H. Aerosol Sci, Techn. 1998, 29, 112. (12) Nadykto, A. B.; AI Natsheh, A.; Yu, F.; Mikkelsen, K. V.; Herb, J. Ad. Quantum Chem. 2008, 55, 449. (13) Kurteń, T.; Torpo, L.; Sundberg, M. R.; Kerminen, V.-M.; Vehkama¨ki, H.; Kulmala, M. Atmos. Chem. Phys. 2007, 7, 2765. (14) Yu, F. J. Geophys. Res. 2006, 111, D01204. (15) Nadykto, A. B.; Yu, F. J. Geophys. Res. 2003, 108, 4717. (16) Nadykto, A. B.; Yu, F.; Herb, J. Phys. Chem. Chem. Phys. 2008, 10, 7073. (17) Zhang, R.; Suh, I.; Zhao, J.; Zhang, D.; Fortner, E. C.; Tie, X.; Molina, L. T.; Molina, M. J. Science 2004, 304, 1487. (18) Nadykto, A. B.; Yu, F. Chem. Phys. Lett. 2008, 435, 14. (19) Xu, Y. S.; Nadykto, A. B.; Yu, F.; Herb, J.; Wang, W. J. Phys. Chem. A 2010, 114, 387. (20) Zhao, J.; Khalizov, A.; Zhang, R.; McGraw, R. J. Phys. Chem. A 2009, 113, 680. (21) Kurteń, T.; Loukonen, H.; Vehkama¨ki, H.; Kulmala, M. Atmos. Chem. Phys. 2008, 8, 4095. (22) Xu, Y. S.; Nadykto, A. B.; Yu, F. Q.; Jiang, L.; Wang, W. J. Mol. Struc. (Theochem) 2010, 951, 28. (23) Sun, J.; Ariya, P. A. Atmos. EnViron. 2006, 40, 795. (24) Adachi, K.; Buseck, P. R. Atmos. Chem. Phys. 2008, 8, 6469. (25) Smith, J. N.; Dunn, M. J.; VanReken, T. M.; Iida, K.; Stolzenburg, M. R.; McMurry, P. H.; Huey, L. G. Geophys. Res. Lett. 2008, 35, art. no. L04808. (26) Sellegri, K.; Hanke, M.; Umann, B.; Arnold, F.; Kulmala, M. Atmos. Chem. Phys. 2005, 5, 373. (27) Boy, M.; Karl, T.; Turnipseed, A.; Mauldin, R. L.; Kosciuch, E.; Greenberg, J. Atmos. Chem. Phys. Disc. 2007, 7, 15581. (28) Bonn, B.; Korhonen, H.; Peta¨ja¨, T.; Boy, M.; Kulmala, M. Atmos. Chem. Phys. 2007, 7, 2893. (29) Parshintsev, J.; Nurmi, J.; Kilpelaïnen, I.; Hartonen, K.; Kulmala, M.; Riekkola, M.-L. Analytic.Bioanalytic. Chem. 2008, 390, 913. (30) Bonn, B.; Kulmala, M.; Riipinen, I.; Sihto, S.-L.; Ruuskanen, T. M. J. Geophys. Res. D: Atmospheres 2008, 113, 27. (31) Ding, C.-G.; Laasonen, K.; Laaksonen, A. J. Phys. Chem. A. 2003, 107, 8648. (32) Kurteń, T.; Sundberg, M. R.; Vehkama¨ki, H.; Noppel, M.; Blomqvist, J.; Kulmala, M. J. Phys. Chem. A 2006, 110, 7178.

Reaction of Criegee Intermediates with SO2 (33) Kurteń, T.; Torpo, L.; Ding, C.-G.; Vehkama¨ki, H.; Sundberg, M. R.; Laasonen, K.; Kulmala, M. J. Geophys. Res. 2006b, 112, D4, D04210. (34) Nadykto, A. B.; Du, H.; Yu, F. Vibr. Spectr. 2007, 44, 286. (35) Al Natsheh, A.; Nadykto, A. B.; Mikkelsen, K. V.; Yu, F.; Ruuskanen, J. J. Phys. Chem. A 2004, 108, 8914. (36) Kotzias, D.; Fytianos, K.; Geiss, F. Atmos. EnViron. 1990, 24A, 2127. (37) Lamb, B.; Gay, D.; Westberg, H.; Pierce, T. Atmos. EnViron. 1993, 27A, 1673. (38) Atkinson, R. J. Phys. Chem. Ref. Data 1997, 26, 215. (39) Atkinson, R. Atmos. EnViron. 2000, 34, 2063. (40) Paulson, S. E.; Orlando, J. J. Geophys. Res. Lett. 1996, 23, 3727. (41) Ariya, P. A.; Sander, R.; Crutzen, P. J. J. Geophys. Res. [Atmos.] 2000, 105, 17721. (42) Lee, M.; Heikes, B. G.; Sullivan, D. W. O. Atmos. EnViron. 2000, 34, 3475. (43) Criegee, R.; Wenner, G. Annales 1949, 564, 9. (44) Hatakeyama, S.; Akimoto, H. Res. Chem. Intermed. 1994, 20, 503. (45) Niki, H.; Maker, P. D.; Savage, C. M.; Breitenbach, L. P. Chem. Phys. Lett. 1977, 46, 327. (46) Ryzhkov, A. B.; Ariya, P. A. Chem. Phys. Lett. 2003, 367, 423. (47) Criegee, R. Angew. Chem., Int. Ed. Engl. 1975, 14, 745. (48) Neeb, P.; Horie, O.; Moortgat, G. K. Chem. Phys. Lett. 1995, 246, 150. (49) Hatakeyama, S.; Bandow, H.; Okuda, M.; Akimoto, H. J. Phys.Chem. 1981, 85, 2249. (50) Kurteń, T.; Bonn, B.; Vehkama¨ki, H.; Kulmala, M. J. Phys. Chem. A 2007, 111, 3394. (51) Calvert, J. G.; Lazrus, A.; Kok, G. L.; Heikes, B. G.; Walega, J. G.; Lind, J.; Cantrell, C. A. Nature 1985, 317, 27. (52) Hatakeyama, S.; Kobayashi, H.; Lin, Z. Y.; Tagaki, H.; Akimoto, H. J. Phys. Chem. 1986, 90, 4131. (53) Calvert, J. G.; Stockwell, W. R. EnViron. Sci. Technol. 1983, 17, 428A. (54) Guenther, A.; Geron, C.; Pierce, T.; Lamb, B.; Harley, P.; Fall, R. Atmos. EnViron. 2000, 34, 2205. (55) Ramı´rez-Ramı´rez, V. M.; Nebot-Gil, I. Chem. Phys. Lett. 2005, 409, 23. (56) Atkinson, R.; Lloyd, A. J. Phys. Chem. Ref. Data 1984, 13, 315. (57) Horie, O.; Moortgat, G. K. Atmos. EnViron. 1991, 25A, 1881. (58) Leungsakul, S.; Jaoui, M.; Kamens, R. M. EnViron. Sci. Technol. 2005, 39, 9583. (59) Leungsakul, S.; Jeffries, H. E.; Kamens, R. M. Atmos. EnViron. 2005, 39, 7063. (60) Cox, R. A.; Penkett, S. A. J. Chem. Soc., Faraday Trans. I 1972, 68, 1735. (61) Hatakeyama, S.; Kobayashi, H.; Akimoto, H. J. Phys. Chem. 1984, 88, 4736. (62) Martinez, R. I.; Herron, J. T. Chem. Phys. Lett. 1980, 72, 77.

J. Phys. Chem. A, Vol. 114, No. 47, 2010 12461 (63) Martinez, R. I.; Herron, J. T. EnViron. Sci. Health Part A 1981, A16, 623. (64) Martinez, R. I.; Herron, J. T. EnViron. Sci. Health Part A 1983, A18, 739. (65) Aplincourt, P.; Ruiz-Lo´pez, M. F. J. Am. Chem. Soc. 2000, 122, 8990. (66) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A.; Jr.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A., Gaussian 03, Revision E.01; Gaussian, Inc.: Wallingford, CT, USA, 2004. (67) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (68) Hariharan, P. C.; Pople, J. A. Theor. Chim. Acta 1973, 28, 213. (69) Gonzalez, C.; Schlegel, H. B. J. Chem. Phys. 1989, 90, 2154. (70) Szabo, A.; Ostlund, N. S. Modern Quantum Chemistry: Introduction to AdVanced Electronic Structure Theory; Macmillan: New York, 1986; pp 285-296. (71) Lei, W.; Derecskei-Kovacs, A.; Zhang, R. J. Chem. Phys. 2000, 113, 5354. (72) Suh, I.; Lei, W.; Zhang, R. J. Phys. Chem. A 2001, 105, 6471. (73) Zhang, D.; Zhang, R. J. Am. Chem. Soc. 2002, 124, 2692. (74) Jiang, L.; Wang, W.; Xu, Y. S. Int. J. Mol. Sci. 2009, 10, 3743. (75) Jiang, L.; Wang, W.; Xu, Y. S. Chem. Phys. 2010, 368, 108. (76) Gutbrod, R.; Schindler, R. N.; Kraka, E.; Cremer, D. Chem. Phys. Lett. 1996, 252, 221. (77) Gutbrod, R.; Kraka, E.; Schindler, R. N.; Cremer, D. J. Am. Chem. Soc. 1997, 119, 7330. (78) Olzmann, M.; Kraka, E.; Cremer, D.; Gutbrod, R.; Andersson, S. J. Phys. Chem. A 1997, 101, 9421. (79) Cremer, D.; Kraka, E.; Szalay, P. G. Chem. Phys. Lett. 1998, 292, 97. (80) Aplincourt, P.; Ruiz-Lo´pez, M. F. J. Phys. Chem. A 2000, 104, 380. (81) Aplincourt, P.; Anglada, J. M. J. Phys. Chem. A 2003, 107, 5798. (82) Xu, F.; Wang, H.; Zhang, Q. Z.; Zhang, R. X.; Qu, X. H.; Wang, W. X. EnViron. Sci. Technol. 2010, 44, 1399. (83) Sun, X. Y.; He, M. X.; Zhang, Q. Z.; Wang, W. X.; Jalbout, A. F. J. Mol. Struc.: THEOCHEM 2008, 868, 87.

JP107783Z

Reaction of Stabilized Criegee Intermediates from Ozonolysis of

Recommend Documents