A comparison of the absorption spectra of the fluorobenzenes and benzene in the region 4.5-9.5 eV

The gas-phase extinction-coefficient spectra of ten fluorosubstituted benzenes are presented and compared with benzene in the region 4.5-9.5 eV. The three singlet-singlet transitions analogous to the B 2u from A 1g , B 1u from A 1g and E 1u from A 1g transitions of benzene are presented and discussed. The appearance of the elusive 1 E 2g state is reported in 1,3,5-TFBz and two tetrafluorobenzenes, while in monofluorobenzene and o-DFBz the 3s and 4s members of the 1 E 1g Rydberg state are detected. From this work the authors conclude that they have the following order for benzene: 1 B 2u < 1 B 1u <3s( 1 E 1g )< 1 E 1u