Isoprene NO3 Oxidation Products from the RO2 + HO2 Pathway.
J Phys Chem A
; 119(40): 10158-71, 2015 Oct 08.
Article
in En
| MEDLINE
| ID: mdl-26335780
ABSTRACT
We describe the products of the reaction of the hydroperoxy radical (HO(2)) with the alkylperoxy radical formed following addition of the nitrate radical (NO(3)) and O(2) to isoprene. NO(3) adds preferentially to the C(1) position of isoprene (>6 times more favorably than addition to C(4)), followed by the addition of O(2) to produce a suite of nitrooxy alkylperoxy radicals (RO(2)). At an RO(2) lifetime of â¼30 s, δ-nitrooxy and ß-nitrooxy alkylperoxy radicals are present in similar amounts. Gas-phase product yields from the RO(2) + HO(2) pathway are identified as 0.75-0.78 isoprene nitrooxy hydroperoxide (INP), 0.22 methyl vinyl ketone (MVK) + formaldehyde (CH(2)O) + hydroxyl radical (OH) + nitrogen dioxide (NO(2)), and 0-0.03 methacrolein (MACR) + CH(2)O + OH + NO(2). We further examined the photochemistry of INP and identified propanone nitrate (PROPNN) and isoprene nitrooxy hydroxyepoxide (INHE) as the main products. INHE undergoes similar heterogeneous chemistry as isoprene dihydroxy epoxide (IEPOX), likely contributing to atmospheric secondary organic aerosol formation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Phys Chem A
Journal subject:
QUIMICA
Year:
2015
Document type:
Article
Affiliation country:
United States