The 2699 Å Electronic Band System of Chlorobenzene—The In-Plane Vibrational Modes in the Excited State

Abstract

The electronic absorption spectrum of chlorobenzene, obtained with medium resolution and dispersion, has been reported earlier; but the vibrational analysis has been confined to noting a few prominent band intervals from the 0,0 (origin) band. No data from rotational contour analysis were available in literature. Employing the method developed earlier for the rovibronic analysis of phenol, we have been able to obtain accurate vibrational data for the low-lying planar vibrations in the ground state, eA1, of chlorobenzene. In this note we wish to report the vibrational assignments of the totally symmetric a1 and nontotally symmetric b2 fundamentals of the molecule in its first singlet excited state, eB2, based primarily on the identification of Ae and Be-type band contours from the high resolution electronic spectrum.