Lowhyphen;Temperature Absorption Spectra of Benzene, Toluene, and Parahyphen;Xylene in the Farther Ultraviolet Region

摘要

The absorption spectra of the 2100 A and 1850 A transitions of benzene, toluene, and parahyphen;xylene show sharp structure at low temperature. The sharp structure of the 1850 A transition shows that it is a pgr;mdash;pgr; type transition, and not a dissociation band. Its correct assignment is1A1glarr;1E1u, with analogous assignments in toluene and parahyphen;xylene. The 2100 A transitions of these molecules can be assigned to1A1glarr;1B1uand its analogs, while the 2600 A transitions are assigned to1A1glarr;1B2u. Evidence presented indicates that there is no1A1glarr;1E2gtransition in this region of the spectrum.