The infrared spectra of two fullerene derivatives, C60O and C61H2, hav
e been measured in the 4000-200 cm(-1) frequency range between 10 K an
d room temperature. Due to symmetry lowering with respect to C-60, the
infrared activity favors the assignment of the C-60 Silent modes. The
experimental results are compared with vibrational calculations based
on semiempirical methods. The frequencies of the epoxide and CH2 brid
ges have been identified in the spectrum and correlated with calculate
d values. Both the O and CH2 bridges cause local perturbations of the
C-60 cluster and do not significantly change the vibrations of the cag
e. Temperature effects on the infrared spectra are briefly discussed.