High resolution electronic absorption spectrum of 1, 3, 5-trifluorobenzene

Abstract

The near ultraviolet electronic absorption spectrum of 1,3,5 trifluorobenzene has been photographed on a 10.6 m concave grating spectrograph. The electronic forbidden transition 1A'2 ←- 1A'1 is explained as arising due to perturbation of the electronic state by non-totally symmetric vibration V6. Besides V6, the other modes of e' species V8, V9, V18, and v19 are also active and give rise to false origins. The vibrational frequencies for V9, V18, V 19, V8, V13, V1 and V16 modes in the first electronic excited state 1A'2 are reported for the first time.