Journal of Physical Chemistry A, Vol.106, No.16, 3998-4004, 2002
Internal rotation and intermolecular vibrations of the phenol-methanol cluster: A comparison of spectroscopic results and ab initio theory
The vibronic spectra of five deuterated species of the binary phenol-methanol cluster are compared to the intermolecular vibrational frequencies of an ab initio-based normal-mode analysis. Isotopomers with equal mass could be distinguished experimentally using spectral hole-burning spectroscopy. The vibronic bands of phenol-methanol are split into A and E components because of the internal rotation of the methyl group. This torsional splitting is increased for three of the intermolecular vibrations because of coupling to the large-amplitude motion. Guided by comparison to an ab initio normal-mode analysis and by the torsional splitting of some of the vibronic bands, a complete intermolecular vibrational assignment for the phenol-methanol cluster is presented.