title: Secondary organic aerosol from aqueous reactions of green leaf volatiles with organic triplet excited states and singlet molecular oxygen.
abstract: Vegetation emits a class of oxygenated hydrocarbons--the green leaf volatiles (GLVs)--under stress or damage. Under foggy conditions GLVs might be a source of secondary organic aerosol (SOA) via aqueous reactions with hydroxyl radical (OH), singlet oxygen ((1)O2*), and excited triplet states ((3)C*). To examine this, we determined the aqueous kinetics and SOA mass yields for reactions of (3)C* and (1)O2* with five GLVs: methyl jasmonate (MeJa), methyl salicylate (MeSa), cis-3-hexenyl acetate (HxAc), cis-3-hexen-1-ol (HxO), and 2-methyl-3-butene-2-ol (MBO). Second-order rate constants with (3)C* and (1)O2* range from (0.13-22) × 10(8) M(-1) s(-1) and (8.2-60) × 10(5) M(-1) s(-1) at 298 K, respectively. Rate constants with (3)C* are independent of temperature, while values with (1)O2* show significant temperature dependence (Ea = 20-96 kJ mol(-1)). Aqueous SOA mass yields for oxidation by (3)C* are (84 ± 7)%, (80 ± 9)%, and (38 ± 18)%, for MeJa, MeSa, and HxAc, respectively; we did not measure yields for other conditions because of slow kinetics. The aqueous production of SOA from GLVs is dominated by (3)C* and OH reactions, which form low volatility products at a rate that is approximately half that from the parallel gas-phase reactions of GLVs.
authors.affiliation: Department of Land, Air and Water Resources, University of California - Davis , 1 Shields Avenue, Davis, California 95616, United States.
authors.forename: Nicole K
authors.initials: NK
authors.lastname: Richards-Henderson
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pham
authors.forename: Benjamin B
authors.initials: BB
authors.lastname: Kirk
authors.forename: Cort
authors.initials: C
authors.lastname: Anastasio
mesh_terms: D000085:Acetates / Q000737:chemistry; D000336:Aerosols / Q000737:chemistry*; D003517:Cyclopentanes / Q000737:chemistry; D000441:Hexanols / Q000737:chemistry; D017665:Hydroxyl Radical; D007700:Kinetics; D010100:Oxygen / Q000737:chemistry; D054883:Oxylipins / Q000737:chemistry; D000439:Pentanols / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D012459:Salicylates / Q000737:chemistry; D026082:Singlet Oxygen; D013696:Temperature; D055549:Volatile Organic Compounds / Q000737:chemistry*; D014835:Volatilization; D014867:Water / Q000737:chemistry
chemical_list: D000085:Acetates; D000336:Aerosols; D003517:Cyclopentanes; D000441:Hexanols; D054883:Oxylipins; D000439:Pentanols; D012459:Salicylates; D055549:Volatile Organic Compounds; D014867:Water; D026082:Singlet Oxygen; C051918:3-hexen-1-ol; D017665:Hydroxyl Radical; C425828:3-hexenylacetate; C072239:methyl jasmonate; C033069:methyl salicylate; D010100:Oxygen; C027250:3-hydroxy-3-methylbutene