Scaled quantum mechanical study of 2,6-difluorophenol: a fluorine-containing weak hydrogen-bonded system

The vibrational spectra of 2,6-difluorophenol were recorded in the gas-phase (FT-IR) and in CCl4 solution (FT-IR, FT-Raman). The interpretation of the spectra was based on a scaled Becke3-Lee-Yang-Parr/6–31G∗ force field utilising a set of scale factors introduced recently by Rauhut and Pulay. The scale factors were found to be transferable to flourine; however, poor results were obtained for the vibrations of the hydroxy group affected strongly by the hydrogen bonding. The set was extended to fluorine-containing weak hydrogen-bonded systems: based on the present results additional scale factors are recommended for the hydrogen-bonded OH stretching and (conjugated) OH torsional vibrations.