Assessing Potential Oligomerization Reaction Mechanisms of Isoprene Epoxydiols on Secondary Organic Aerosol

Stropoli, Santino J.; Miner, C. R.; Hill, Daniel R.; Elrod, Matthew J.

doi:10.1021/acs.est.8b05247

Cited by 9 publications

(21 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mole fraction-based nucleophilic strengths of sulfate on the order of 10 (defined relative to water) can be compared to previous nucleophilic strength measurements on the order of unity for alcohols, 26 10 for nitrate, 12,39 100 for halides, 39 and 1000 for amines. 45 Therefore, in an aerosol environment in which many different nucleophiles are present, sulfate may be in a competitive situation with other nonwater nucleophiles with respect to the epoxide reaction.…”

Section: ■ Methods and Materialsmentioning

confidence: 99%

“…19,24,25 However, the mechanisms by which such oligomers may form remain unclear. 26 Since the IEPOX-derived organosulfates form via nucleophilic addition reactions of SO 4 2− and/or HSO 4 − , and the organosulfate derivatives themselves are of the form RSO 4…”

Section: ■ Introductionmentioning

confidence: 99%

“…The bulk solution method allows for careful control over reactant and catalyst species, as well as their concentrations, and the NMR method can be used to determine isomer-specific structures and relative concentrations for product species. 26,28 We also systematically investigate the carbon substitution and functional group dependence of various epoxides in their nucleophilic reactions with sulfate and that of a model organosulfate, methyl sulfate anion (CH 3 OSO 3 − ), in order to assess the likelihood of oligomer-forming nucleophilic addition of organosulfates to epoxide reactions on SOA.…”

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Determining the Relative Reactivity of Sulfate, Bisulfate, and Organosulfates with Epoxides on Secondary Organic Aerosol

Aoki

Sarrimanolis

Lyon

et al. 2020

ACS Earth Space Chem.

Self Cite

View full text Add to dashboard Cite

Extensive laboratory and field studies have identified nucleophilic addition reactions of isoprene epoxydiols (IEPOX) as key pathways for the formation of isoprene-derived secondary organic aerosol (SOA). Organosulfates are important reaction products of these processes, but it is unclear whether sulfate and/or bisulfate nucleophiles are responsible for their formation and whether the organosulfates themselves can serve as nucleophiles in oligomer-forming reactions. The relative reactivities (nucleophilic strengths relative to water) of sulfate, bisulfate, and methyl sulfate anion were measured through a series of model epoxide–nucleophile experiments using nuclear magnetic resonance (NMR) spectroscopy. These experiments also helped establish a rigorous understanding of the effects of differing carbon substitution and functional groups of epoxides on the modulation of the effective nucleophilicites of sulfate, bisulfate, and methyl sulfate anions. It was determined that the nucleophilicites of bisulfate and methyl sulfate anions were about 100 and 50 times, respectively, weaker than sulfate toward most of the epoxides studied, which was rationalized by computational estimates of their thermodynamic basicities. Therefore, for most SOA acidity situations, sulfate–epoxide reactions are expected to be the main source of organosulfate aerosol constituents. Because sulfate–epoxide reactions stoichiometrically consume acid, these reactions also have the capability of raising the pH of SOA, thus slowing down all acid-catalyzed chemical processes. No evidence for the reaction of the methyl sulfate anion was observed with the abundant atmospherically relevant epoxide, trans-β-IEPOX, thus suggesting that oligomerization reactions via epoxide–organosulfate reactions may not be able to compete with stronger (such as sulfate) or more abundant (such as water) nucleophiles on actual SOA.

show abstract

Section: ■ Methods and Materialsmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Determining the Relative Reactivity of Sulfate, Bisulfate, and Organosulfates with Epoxides on Secondary Organic Aerosol

Aoki

Sarrimanolis

Lyon

et al. 2020

ACS Earth Space Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Diols, and these olefinic diols, can also undergo oligomerization to form even lower volatility products which may have profound effects on the overall aerosol properties, such as viscosity and rate of diffusion (Glasius and Goldstein, 2016;Slade et al, 2019). The presence of oligomers from diols has previously been identified, but molecular characterization is quite limited (Stropoli et al, 2019). Careful investigation of the structures of these oligomers is necessary.…”

Section: Aqueous Phase Hydrolysismentioning

confidence: 99%

The Production and Hydrolysis of Organic Nitrates from OH Radical Oxidation of β-Ocimene

Morales¹,

Slade²,

Laskin³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. Biogenic volatile organic compounds (BVOCs) emitted by plants represent the largest source of non-methane hydrocarbon emissions on Earth. Photochemical oxidation of BVOCs represents a significant pathway in the production of secondary organic aerosol (SOA), affecting Earth’s radiative balance. Organic nitrates (RONO2), formed from the oxidation of BVOCs in the presence of NOx, represent important aerosol precursors, and affect the oxidative capacity of the atmosphere, in part by sequestering NOx. In the aerosol phase, RONO2 hydrolyze to form nitric acid and numerous water-soluble products, thus contributing to an increase in aerosol mass. However, only a small number of studies have investigated the production of RONO2 from •OH oxidation of terpenes, among those, few have studied their hydrolysis. Here, we report a laboratory study of OH radical-initiated oxidation of β-ocimene, an acyclic, triolefinic monoterpene released during the daytime from vegetation, including forests, agricultural landscapes, and grasslands. We conducted studies of the OH radical oxidation of β-ocimene in the presence of NOx using a 5.5 m3 all-Teflon photochemical reaction chamber, during which we quantified the total (gas- and particle-phase) RONO2 yield and the SOA yields. We sampled the organic nitrates produced and measured their hydrolysis rate constants at different solution pH. The total organic nitrate yield was determined to be 33(±7) %, consistent with the available literature regarding the dependence of organic nitrate production (from RO2 + NO) on carbon number. We found the hydrolysis rate constants to be highly pH-dependent, with a hydrolysis lifetime of 51(±13) min at pH = 4, and 24(±3) min at pH = 2.5, a typical pH for deliquesced aerosols. We also employed high-resolution mass spectrometry for product identification, which is used to infer key mechanisms of gas–particle partitioning. The results indicate that the ocimene SOA yield under relevant aerosol mass loadings in the atmosphere is significantly lower (

show abstract

“…Isoprene derived epoxides are very important intermediates, which could explain at least in part the composition of ambient SOA both in urban areas (Lin et al, 2013) and remote regions (Jacobs et al, 2013;Stropoli et al, 2019;Paulot et al, 2009;Jacobs et al, 2013;Shrivastava et al, 2019). The toxicity of ultrafine particles such as SOA is not only related to their atmospheric concentration but also to the nature and chemical properties of both the precursors and the formed SOA components (Jiang et al, 2019).…”

mentioning

confidence: 99%

Kinetic Study of the Atmospheric Oxidation of a Series of Epoxy Compounds by OH Radicals

Tovar

Barnes

Bejan

et al. 2021

Preprint

View full text Add to dashboard Cite

Abstract. The kinetics of the gas-phase reactions of hydroxyl radicals with cyclohexene oxide (CHO), 1,2-epoxyhexane (EHX), 1,2-epoxybutane (12EB), trans-2,3-epoxybutane (tEB) and cis-2,3-epoxybutane (cEB) have been investigated using the relative rate technique. The experiments have been performed at (298 ± 3) K and (760 ± 10) Torr total pressure of synthetic air using different reference compounds in a 1080 l Quartz Reactor (QUAREC) and a 480 l Duran glass chamber. The following room temperature rate coefficients (cm3 molecule−1 s−1) were obtained: k1 (OH+CHO) = (5.93 ± 1.78) × 10−12, k2 (OH+EHX) = (5.77 ± 1.29) × 10−12, k3 (OH+12EB) = (1.98 ± 0.39) × 10−12, k4 (OH+cEB) = (1.50 ± 0.26) × 10−12, k5 (OH+tEB) = (1.81 ± 0.42) × 10−12. With the exception of previous studies for 1,2-epoxybutane and cyclohexene oxide, this is to the best of our knowledge the first kinetic study of the reaction of these compounds with OH radicals. Atmospheric lifetimes, reactivity trends and atmospheric implications are discussed considering the epoxy compound rate coefficients obtained in the present study. In addition to a direct comparison with the literature data where possible, the results from the present study are compared with values estimated from the Structure Activity Relationship method.

show abstract

Assessing Potential Oligomerization Reaction Mechanisms of Isoprene Epoxydiols on Secondary Organic Aerosol

Cited by 9 publications

References 34 publications

Determining the Relative Reactivity of Sulfate, Bisulfate, and Organosulfates with Epoxides on Secondary Organic Aerosol

Determining the Relative Reactivity of Sulfate, Bisulfate, and Organosulfates with Epoxides on Secondary Organic Aerosol

The Production and Hydrolysis of Organic Nitrates from OH Radical Oxidation of β-Ocimene

Kinetic Study of the Atmospheric Oxidation of a Series of Epoxy Compounds by OH Radicals

Contact Info

Product

Resources

About