A dichotomy in the nitration of fluoranthene with NO sub 2 /N sub 2 O sub 4 : Mechanistic and toxicological implications
- Louisiana State Univ., Baton Rouge (United States)
The nitration of fluoranthene with nitrogen dioxide can occur by two distinctive reaction pathways. These paths can be distinguished by product analysis, since fluoranthene is a nonalternant hydrocarbon. Free-radical nitration and electrophilic nitration give different products. In solvents with dielectric constants lower than that of CH{sub 2}Cl{sub 2} and in the absence of acid catalysis, the exclusive reaction pathway is homolytic in nature. The products of the homolytic reaction pathway can be interpreted as arising via a multiple-step addition-elimination mechanism and are notable for the formation of 2-nitrofluoranthene (the major product in CCl{sub 4} but absent under electrophilic nitration conditions) and the unusually large amounts of the expected 1,2-dinitrofluoranthene and 1,3-dinitrofluoranthene. The ionic reaction pathway is subject to both Lewis and Bronsted acid catalysis, particularly in CH{sub 2}Cl{sub 2}, and is inhibited by nonnucleophilic bases like 2,6-di-tert-butylpyridine. At temperatures lower than 25C, the ionic reaction pathway predominates, even in CCl{sub 4}. 2-Nitrofluoranthene is a marker for the free-radical nitration of fluoranthene, and its presence in polluted tropospheric air suggests that free-radical nitration by NO{sub 2} may occur under atmospheric conditions.
- OSTI ID:
- 5955562
- Journal Information:
- Journal of Organic Chemistry; (United States), Journal Name: Journal of Organic Chemistry; (United States) Vol. 55:9; ISSN JOCEA; ISSN 0022-3263
- Country of Publication:
- United States
- Language:
- English
Similar Records
Studies on the reactions of polycyclic aromatic hydrocarbons with nitrogen dioxide in aprotic solvents
Reaction of dinitrogen pentoxide with fluoranthene
Related Subjects
400201* -- Chemical & Physicochemical Properties
AROMATICS
BROENSTED ACIDS
CATALYSIS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CONDENSED AROMATICS
HOMOGENEOUS CATALYSIS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IONS
KINETICS
LEWIS ACIDS
METHYLENE CHLORIDE
NITRATION
NITRO COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLYCYCLIC NITRO COMPOUNDS
RADICALS
REACTION KINETICS