Note on the Ultraviolet Absorption Systems of Benzene Vapor

Abstract

An attempt has been made to give a coherent interpretation of the absorption systems of benzene vapor in the far ultraviolet including the Rydberg series. The following assignments are proposed: A forbidden transition of symmetry 1A1g→1B1u is suggested for the bands at 2050 to 1850A and an allowed 1A1g→1E—u transition for the much more intense bands at 1850 to 1650A. The continuous background in the latter region may possibly be due to a transition involving a C–H dissociation. The observed two Rydberg series can both be assigned to allowed transitions of symmetry 1A1g→1E—u.