TB11		15min11:33

MASARU FUKUSHIMA, Advanced Technology Research Center, Mitsubishi Heavy Industries, LTD., Sachiura, Kanazawa, Yokohama 236, Japan; KINICHI OBI, Department of Chemistry, Tokyo Institute of Technology, Ohokayama, Meguro, Tokyo 152, Japan.

We have generated the p-cyanobenzyl radical in supersonic free expansion, and measured the laser induced fluorescence ( LIF ) spectra in green-blue region; the vibrationally and rotationally resolved LIF excitation spectra and the LIF dispersed spectra from the single vibronic levels ( SVL ). On the basis of the vibronic structures in the SVL dispersed spectra, the lowest energy band at 20735 cm^-1 with the strongest intensity in the excitation spectrum has been assigned to the 0₀⁰ band of the visible spectrum. Based on the band type of the 0₀⁰ band, a-type, determined from the rotationally resolved LIF excitation spectrum, we have definitely assigned the visible band to the D₁ 2²B₁ -- D₀ 1²B₁ electronic transition. We have found on the grounds of the vibrational analysis of the dispersed spectra, that the vibronic structure of the 2²B₁ -- 1²B₁ electronic transition of the benzyl type was characterized by totally symmetric fundamental modes, 1, 8a, and 9a, with the frequencies higher than 800 cm^-1, while those of the 1²A₂ -- 1²B₁ electronic transition are non-totally symmetric modes, 6b and 8b, and totally symmetric modes, 6a and 1, with the frequencies lower than 800 cm^-1 .