Dicarbonyl products of the OH radical-initiated reactions of naphthalene and the Cl- and C2-alkylnaphthalenes.
Naphthalene and the C1- and C2-alkylnaphthalenes are the most abundant polycyclic aromatic hydrocarbons (PAHs) in urban atmospheres. Their major atmospheric loss process is by gas-phase reaction with hydroxyl (OH) radicals. In this study, we have used in situ direct air sampling atmospheric pressure ionization mass spectrometry (API-MS) as well as gas chromatography-mass spectrometry (GC/MS) techniques to investigate the products of the gas-phase reactions of OH radicals with naphthalene, naphthalene-ds, 1- and 2-methylnaphthalene (MN), 1- and 2-MN-dio, 1- and 2-ethylnaphthalene (EN), and the 10 isomeric dimethylnaphthalenes (DMNs). The major reaction products are ring-opened dicarbonyls that are 32 mass units higher in molecular weight than the parent compound, one or more ring-opened dicarbonyls of lower molecular weight resulting from loss of two P-carbons and associated alkyl groups, and ring-containing compounds that may be epoxides. Phthalic anhydride and alkyl-substituted phthalic anhydrides were observed as second generation products. The position of alkyl-substitution on the naphthalene ring is a key factor determining the ring cleavage site and the isomeric product distribution.
Wang
Lin
L
Environmental Toxicology Graduate Program, Department of Environmental Sciences, University of California, Riverside, California 92521, USA.
Atkinson
Roger
R
Arey
Janet
J
D017606:Chlorine Compounds / Q000737:chemistry*; D002849:Chromatography, Gas / Q000379:methods; D004785:Environmental Pollutants / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*
D017606:Chlorine Compounds; D004785:Environmental Pollutants; D009281:Naphthalenes; C031721:naphthalene; D017665:Hydroxyl Radical