Temperature dependence of FT IR spectra of C-60 and its clathrates and
complexes with various, specifically selected compounds has been meas
ured in the temperature range 80 to 340 K. The bandwidth, integral int
ensity and peak wave number of the four most intensive C-60 bands have
been found to change at the phase transition temperature region. The
observed peculiarities of the IR parameters have been ascribed to the
rotational-vibrational coupling.