Photochemical reaction of nitro-polycyclic aromatic hydrocarbons: Effect by solvent and structure

Department of Chemistry, Jackson State University, Jackson, MS 39217, USA.
Environmental Chemistry Letters (Impact Factor: 2.57). 12/2010; 8(4):301-306. DOI: 10.1007/s10311-009-0221-2
Source: PubMed

ABSTRACT Photochemical degradation of 1-nitropyrene, 2-nitrofluorene, 2,7-dinitrofluorene, 6-nitrochrysene, 3-nitrofluoranthene, 5-nitroacenaphthene, and 9-nitroanthracene were examined in CHCl(3), CH(2)Cl(2), DMF, DMF/H(2)O (80/20), CH(3)CN, or CH(3)CN/H(2)O (80/20). The degradation follows mostly the 1(st) order kinetics; but a few follow 2(nd) order kinetics or undergo self-catalysis. The photodegradation rates follow the order: CHCl(3) > CH(2)Cl(2) > DMF > DMF/H(2)O > CH(3)CN > CH(3)CN/H(2)O. DMF is an exceptional solvent because 3 of the 7 compounds undergo self-catalytic reaction. 9-Nitroanthracene, which has a perpendicular nitro group, is the fastest, while the more compact 1-nitropyrene and 3-nitrofluoranthene, are the slowest degrading compounds.

Download full-text


Available from: Hongtao Yu, Apr 17, 2014
1 Follower
31 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons (NPAHs) in PM10 at a roadside site in Xiamen, China. At the same time, six PM10 samples were collected from a nearby roadway tunnel for comparison. Six NPAHs, namely 9-nitroanthracene, 2- and 3-nitrofluoranthene, 1-nitropyrene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene, were identified and quantified using GC/MS in negative ion chemical ionization mode. The average total concentration of six NPAHs (sigmaNPAHs) in the cold season (26 Nov-31 Dec) was 2.3 (daytime) and 9.9 (nighttime) times higher than those in the warm season. Significant statistical difference (p < 0.01, 2-tailed) of sigmaNPAHs between daytime and nighttime was found during both the warm and cold seasons. NPAHs were significantly positively correlated with their parent PAHs and nitrogen dioxide but negatively correlated with ambient temperature. The ratio of 2 + 3-nitrofluoranthene to 1-nitropyrene exhibited a similar diurnal pattern as sigmaNPAHs and was generally greater than 5, indicating the importance of secondary atmospheric formation. The diurnal variations of NPAHs were all influenced by the diurnal variations of PAHs, nitrogen dioxide, sunlight, and temperature. The daily inhalable exposure to the six NPAHs in the tunnel was much higher than the roadside values in the warm season but only slightly higher than those in the cold season.
    Journal of Environmental Sciences 10/2012; 24(10):1767-76. DOI:10.1016/S1001-0742(11)61018-8 · 2.00 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pyrene, one of the most studied polycyclic aromatic hydrocarbons, can damage biological macromolecules and cause toxicity when irradiated by light. The effect of substituents, 1-amino, 1-hydroxy, 1-nitro, and 1-bromo, on light-induced lipid peroxidation is studied. Degradation kinetics and photoproduct analyses were conducted to test how these substituents affect the photoreaction. All five compounds have widely different photodegradation rates, with degradation half-lives, ranging from 8 min to 495 min. These rates parallel their light absorptivity. Four out of the five compounds induce lipid peroxidation when irradiated with UVA light, whereas 1-aminopyrene causes minimum or no lipid peroxidation. The relative amount of lipid peroxidation caused is: 1-bromopyrene > pyrene > 1-nitropyrene ≈ 1-hydroxypyrene > 1-aminopyrene. This relative lipid peroxidation is dependent on the substituent due to the following factors: light absorptivity, relative rates of the competing processes in the excited states, nature of the photoreaction, and nature of the photoproducts.
    Journal of Environmental Science and Health Part A Toxic/Hazardous Substances & Environmental Engineering 02/2013; 48(3):233-41. DOI:10.1080/10934529.2013.729998 · 1.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Vehicle pollution is an increasing problem in the industrial world. Aromatic nitro compounds comprise a significant portion of the threat. In this review, the class includes nitro derivatives of benzene, biphenyls, naphthalenes, benzanthrone and polycyclic aromatic hydrocarbons, plus nitroheteroaromatic compounds. The numerous toxic manifestations are discussed. An appreciable number of drugs incorporate the nitroaromatic structure. The mechanistic aspects of both toxicity and therapy are addressed in the context of a unifying mechanism involving electron transfer, reactive oxygen species, oxidative stress and antioxidants. Copyright © 2014 John Wiley & Sons, Ltd.
    Journal of Applied Toxicology 08/2014; 34(8). DOI:10.1002/jat.2980 · 2.98 Impact Factor
Show more