ORGN 25 |
| Yilei Zhao, Dept. of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095-1569 and K. N. Houk, Department of Chemistry and Biochemistry, University of California Los Angeles, 405 Hilgard Ave, Los Angeles, CA 90095-1569. |
| S-Nitrosothiols (RSNO) have been suggested as physiologically active species in nitric oxide chemistry. However, the decompositions of nitrosothiols are faster than homolysis of the S-N bond under some conditions. We have explored a cationic chain mechanism, which is able to explain several experimental facts: 1) the decomposition is accelerated by O2, mixtures of O2 and NO, excess nitrosonium, and other oxidants; 2) the decomposition is blocked by thiols, high concentrations of NO, p-cresol, and other antioxidants; 3) RSNOs are more stable in polar solvents. We propose a cationic chain mechanism, in which a nitrosylated nitrosothiol reacts with a neutral nitrosothiol. This catalytic cycle produces disulfide and the NO dimer. The computed mechanism will be compared to the experimental data available for this reaction. |
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Physical Organic Chemistry: Calculations, Mechanisms, Photochemistry and High Energy Species
8:00 AM-12:00 PM, Sunday, September 7, 2003 Sheraton New York -- Royal Ballroom A, Oral
Division of Organic Chemistry |