Rotational contour analysis of selected absorption bands of benzyl produced by flash photolysis

Abstract

Three bands of the flash-photolysis absorption spectrum of benzyl in the visible are rotationally analyzed: a type- B band, 6 a 0 1, at 4456 Å, and two type- A bands, A 1 and A 2, at 4477 and 4465 Å, respectively. The band notation is taken from the vibronic analysis of that region of the benzyl electronic spectrum by C. Cossart-Magos and S. Leach. The observed rotational contours were fitted by computer-simulated rotational contours, resulting in the determination of the variations, Δ A, Δ B, and Δ C of the rotational constants accompanying the vibronic transitions corresponding to each band. Different A′, B′, and C′ values are obtained for the three upper levels and are discussed in light of the previous vibronic assignments. The application of the present results to the study of low-temperature rotational band contours in supercooled benzyl spectra is also discussed.