Product and Mechanistic Study of the Reaction of NO₃ Radicals with α-Pinene

Abstract

The reaction between NO 3 and R-pinene has been studied in large reaction chambers of 0.5-200 m 3 volume, using long path FT-IR, GC-ECD, and GC-FID for the analyses. The reaction yielded 62 ( 4% pinonaldehyde (3-acetyl-2,2dimethylcyclobutane acetaldehyde) and 3 ( 0.5% pinane epoxide. The total yield of alkylnitrates was estimated to be approximately 14%; two of the nitrates have been identified as 3-oxypinane-2-nitrate, and 2-hydroxy-3nitrate with yields of 3 ( 0.2% and 5 ( 0.4%, respectively. This work represents the first quantitative identification of pinonaldehyde and alkylnitrates from the reaction of NO 3 with R-pinene. A thermally stable peroxy acylnitrate was observed to be formed from secondary reactions of pinonaldehyde in the system. This compound has been assigned to 3-acetyl-2,2-dimethylcyclobutane acetylperoxynitrate. Possible implications for the atmospheric NO x chemistry are discussed. From the product data, a mechanism for the NO 3 + R-pinene reaction has been constructed.

Direct observations of daytime NO3: Implications for urban boundary layer chemistry

“…Two O x molecules are destroyed by this reaction if organic nitrates are the products. In the case of monoterpenes (which were the most important organic scavenger for NO 3 during afternoon), however, a large fraction of nitrogen is being rereleased during the course of the oxidation in the form of NO 2 (for example %80% in the case of a-pinene, [Wängberg et al, 1997a]). We assume in the following calculation that 1.5 O x molecules are destroyed by each reaction of NO 3 with VOCs.…”

“…Reactions with biogenically emitted monoterpenes [Guenther et al, 2000;Martinez et al, 1999;Wängberg et al, 1997a] and anthropogenic higher alkenes [Atkinson et Figure 5. Comparison of measured NO-to-NO 2 ratios with ratios calculated from Leighton PSS (equation (11), crosses), Leighton PSS including peroxy radicals (equation (13), circles), and Leighton PSS including the peroxy radicals and daytime NO 3 (equation (16), diamonds) at La Porte, Texas.…”

Heterogeneous reaction of particulate chlorpyrifos with NO 3 radicals: Products, pathways, and kinetics

“…NO 3 radicals were generated by thermal decomposition of N 2 O 5 placed at the room temperature (N 2 O 5 ⇔ NO 2 + NO 3 ) [29]. N 2 O 5 was synthesized by dehydrating concentrated nitric acid (2HNO 3 ⇔ N 2 O 5 + H 2 O).…”

“…The NO 3 radicals attack the chlorpyrifos molecule by attaching an oxygen atom on the sulfur atom, giving the intermediate I a . The attachment of an oxygen atom is speculated to be formed by addition of NO 3 radicals, followed by a loss of a NO 2 molecule [29]. The intermediate I a then rearranges, leading to the formation of the diradical intermediate I b [32].…”

Characterisation of solvent extractable organic constituents in atmospheric particulate matter: an overview

“…In laboratory experiments with α-pinene and OH radicals or ozone, the formation of pinonaldehyde and pinonic acid was observed (Hakola et al 1994, Kamens and Jaoui 2001, Larsen et al 2001. Pinonaldehyde may also take place in the particulate phase by oxidation of α-pinene through reaction with other oxidising species such as NO 3 and N 2 O 5 (Wängberg et al 1997). The major product from β-pinene oxidation identified in the particulate matter is nopinone.…”