Düsseldorf 2007 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 13: Photochemistry

MO 13.5: Vortrag

Montag, 19. März 2007, 17:30–17:45, 6B

Femtosecond Experiments on the Photochemistry of Organic N-Oxides — •Nadja Regner, Thorben Cordes, Tobias Schrader, and Peter Gilch — Lehrstuhl für BioMolekulare Optik, Department für Physik, Ludwig-Maximilians-Universität München, Oettingenstr. 67, 80538 München

The photo-rearrangement of organic N-oxides is a useful synthetic tool to synthesize chemicals which are difficult to access by other methods. Therefore, a large variety of N-oxides have been tested for photo-reactivity and in most cases these tests turned out positive [1]. In contrast to this wealth of empirical information our knowledge of the mechanisms of these reactions is poor. In particular, no spectroscopic experiments with a suitable time resolution have yet been published. We here report on a combined femtosecond UV/Vis and IR study on the rearrangement of an N-oxide (2-benzoyl-3-phenylquinoxaline-1,4-dioxide). This rearrangement results in large structural changes which involve several elementary steps occurring with time constants of a few picoseconds to beyond nanoseconds. Based on the femtosescond IR signatures reactions associated with these times constants are suggested. [1] A. Albini and M. Alpegiani Chem. Rev. 84 (1984) 43