Dispersed fluorescence spectroscopy of p-fluorophenol

The laser-induced fluorescence excitation and dispersed fluorescence spectra for S1 ↔ S0 transitions of p-fluorophenol have been measured in a supersonic free jet expansion. Assignments of the vibronic bands of the spectra have been suggested with the aid of the normal mode frequencies predicted by quantum chemistry calculations at DFT/B3LYP/6-311++G(d,p) and CASSCF/6-311G(d,p) levels of theory. Our study reveals that the modes in the excited state are extensively mixed, and the mixing involves the torsion of the phenolic –OH group.