ORGN 409 |
| Dmitry E Polyansky, Center for Photochemical Sciencies, Bowling Green State University, Bowling Green, OH 43402 and Douglas C. Neckers, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403. |
| The direct monitoring of the photodecomposition by NMR in deuterated chloroform and acetonitrile revealed the formation of coumarin-3-carboxylic acid, acetone and tert-butanol as major photochemical products. The transient UV spectrum of coumarin-3-perester has two maxima (400 nm and broad band starting from 550 nm with a maximum at about 800 nm). A similar transient spectrum is described in literature for decomposition of bis(4-methoxybenzoyl) peroxide in acetonitrile and assigned to the benzoyloxy radical. The transient IR spectrum of coumarin-3-perester clearly demonstrates instant formation of a transient at about 1720 cm-1 and subsequent decay (t=2.1ms). Pre-saturation of the sample cell with oxygen caused no changes in the TRIR spectrum or the lifetime. This allowed us to assume that the transient at 1720 cm-1 corresponds to the oxygen centered radical (coumarin carboxy radical). The addition of acrylonitrile, a known radical scavenger, completely eliminated 1720 cm-1 transient. |
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Physical Organic, Materials, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Tuesday, September 9, 2003 Hilton New York -- Americas Hall 1, Poster
Division of Organic Chemistry |