Spectroscopic study of the formation of molecular glasses

The vitrification process of the organic compound 2-biphenylmethanol was studied by IR and low-frequency Raman spectroscopy in the wide temperature range from 320 to 12 K. It has been found that IR spectra on cooling of the supercooled liquid to the glass transition temperature drastically changed only in the spectral region above 3000 cm−1 dominated by the OH-stretching vibration. In the same temperature region in the Raman spectra the quasielastic (relaxational) contribution to the spectra decreases strongly while the boson peak appears and its intensity increases with decreasing temperature. In addition, the crystal structure of 2-biphenylmethanol was determined by X-ray diffraction. The crystals were found to be triclinic with space group P1. Also it has been found that the hydroxyl groups (-OH) of 2-biphenylmethanol molecules form intermolecular hydrogen bonds producing a tetramer local structure, which comprise the crystal structure. The obtained IR and Raman results have been discussed in the light of X-ray studies.