CHED 847 |
| Gernerique Stewart, Scoty Hearst, Yuguo Jiao, and Hongtao Yu. |
| Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are a class of environmental mutagens. Nitro-PAHs undergo various chemical reactions in the environment including photochemical reactions. It has been proposed that the photochemical reaction mechanism of nitro-PAHs depends heavily on the position of the nitro group, whether it is co-planar or perpendicular to the aromatic rings. The co-planar nitro-PAHs usually undergo photochemical oxidation of the aromatic rings, while the perpendicular nitro-PAHs undergo rearrangement of the nitro group first to a nitrite and then to nitroso substituted ketone, which is not stable and easily oxidized further to quinones. However, the nitroso substituted ketone intermediate has never been isolated and characterized. In this study we use 9-nitroanthracene and 9-methyl-10-nitroanthracene to study the rearrangement reaction. Irradiation of 9-methyl-10-nitroanthracene with a UVA lamp (365 nm) in chloroform, methanol, or methanol/water mixture generates the main product that has the molecular mass of the nitroso substituted ketone intermediate. The presence of oxygen turns the intermediate into 9, 10-anthraquinone by comparing with the authentic quinone sample. Irradiation of 9-methyl-10-nitroanthracene in CDCl3 in an NMR tube produced one set of signals that belong to one compound and we are currently assigning all the signals. Irradiation of 9-nitroanthracene in CDCl3 in an NMR tube produced two sets of peaks, which leads to the possibility of other photoproducts. Confirmation of the nitroso intermediates by NMR and mass spectroscopy would prove the light-induced rearrangement mechanism for perpendicularly substituted nitro-substituted aromatic compounds. |
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Undergraduate Research Poster Session: Environmental Chemistry
2:00 PM-4:00 PM, Monday, 27 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Sci-Mix: LSAMP/REU Poster Session
Division of Chemical Education |