Vibrational spectroscopy of fullerenes (C60 and C70). Temperature dependant studies

The FT-Raman and FT-IR spectra of C 60 and C 70 have been obtained under high resolution conditions, both for solid material and in solution. The very small differences in frequency and line width for solution and solid-state spectra are interpreted in terms of minimal intermolecular interactions. The temperature dependence of the infrared modes shows a phase transition near 260 K, in agreement with X-ray results. Below the phase transition temperature, fine structure develops on severam of the infrared modes, indicative of an increase in solid-state interactions