FT IR transmission spectral study of some single crystals of C60 clathrates

FT IR transmission spectra of large single crystals of the clathrates C60·4C6H6,C60·xCCl4 where 0.1<x<0.2, C60·C2HCl3 and C60·1.5CS2 are presented and discussed. Most of the weak lines are identified with activated silent or second-order combination modes of the C60 molecule. It is shown that the number of observed modes and their relative intensities are dependent on the type of the clathrate although all the compounds are of van der Waals type.