VIBRATIONAL SIGNATURES OF FULLERENE OXIDES

Raman and IR spectra of C-60, C60O, C120O and C120O2, measured at room temperature, are discussed using geometric structures, normal modes, Raman and IR intensities from density functional-based tight-binding ( DF-TB) calculations. An assignment of the most important vibrational m odes is given. In the studied compounds the splitting of the C-60 mode s is explained by the removal of degeneracy and the vibrational coupli ng between the C-60 cages. Strong IR absorptions of both dimeric oxide s between 950 and 1150 cm(-1) are assigned to the furan-like structure s connecting the buckyballs. The inter-ball Raman lines below 200 cm(- 1) are shown to be dependent on the bonding strength between the cages . Both the bridge-based IR absorptions and the inter-ball Raman modes are suitable for the identification of the nature and number of bridgi ng structures in oligomeric fullerene oxides.