ORGN 149 |
| Nitric oxide (NO) is important in many chemical processes that occur in mammalian systems. Quinones and semiquinones play a role in biological redox and electron-transfer processes. A unique reaction between these two compounds has been observed. The potassium metal reduction of p-benzoquinone(C6H4O2) in hexamethylphoshoramide (HMPA) followed by exposure to NO gas results in the coupling between NO and p-benzosemiquinone. Re-exposure to more metal generates two new species which are observed via EPR spectroscopy; both are substituted p-benzosemiquinone systems with a nitrogen functional group. Use of 15NO reveals that the nitrogen in these products does not come from the 15NO, but from a condensation reaction with the HMPA. The initial coupling of 15NO and C6H4O2.- results in a concerted C-H bond activation and attack of the HMPA solvent. Nitroxyl (H15NO) is also produced, and 15N-NMR analysis reveals the presence of 15N-nitrous oxide(15N15NO) formed from the dimerization of H15NO. |
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Total Synthesis, Materials, Devices and Switches, Molecular Recognition and Self-Assembly, Biologically-Related Molecules and Processes
8:00 PM-10:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Organic Chemistry |