15min:

RABI CHHANTYAL-PUN, MING-WEI CHEN AND TERRY A. MILLER, Laser Spectroscopy Facility, Department of Chemistry, The Ohio State University, 120 W. 18th Avenue, Columbus OH 43210.

Alkyl nitrites have been used in the past as precursors for producing alkoxy radicals which are important intermediates in combustion and atmospheric chemistry. Substituted alkoxies, particularly hydroxy substituted alkoxy radicals, are important intermediates in the atmospheric chemistry of alkenes. In this talk we will present results obtained from the 351nm photodissociation of XCH₂CH₂ONO (X=F,Cl,Br,OH). The resulting photo-fragments were probed by laser induced fluorescence (LIF) technique downstream of a free-jet expansion. We were not able to observe any transitions resulting from the corresponding XCH₂CH₂O radicals except for FCH₂CH₂ONO. We were able to observe HCHO and also vibrationally hot CH₂CHO from all the different precursors. In CH₂CHO, there is a significant excitation in the CC torsion and CCO bend vibrations. There is also some excitation in CC stretching and CH₂ rock vibrations. HCHO is produced due to dissociation of XCH₂CH₂O in the ground state as the CC scission energy is less than the available photon energy.