FAR-INFRARED SPECTRA OF SOLID METHANOL AT HIGH-PRESSURES

Far-infrared spectra of methanol samples in diamond anvil cells at amb ient temperature and at pressures up to 11 GPa are reported. The liqui d forms a metastable glass at about 3.6 GPa, the absorption spectrum o f which consists of a single broad band which shifts to higher wavenum bers with increase of pressure. On maintaining the pressure at a high value, the glass usually transforms to a crystal and at least five dis tinct peaks are then observed. The evolution of these peak wavenumbers with pressure indicates that no further transitions occur. An increas e in hydrogen bond strength by a factor of about 1.5 is deduced for th e crystal over the pressure range 3.6 to 11 GPa.