Characterization of fullerenes and fullerene derivatives by small-angle neutron scattering and transmission measurements

Small-angle neutron scattering (SANS) I?as been shown to be an appropriate technique for the structural characterization of fullerenes (1) in solvents with strong SANS contrast (e.g. CS2) and we have extended initial studies of C-60 (1) to include C-70 and C-84 moieties. Deuterated solvents (e.g. toluene-dp) have a high scattering length density (SLD), which is close to that of C-60, so there is virtually no SANS contrast with the solvent. Hence, these particles are practically ''invisible'' in such media, though the negative scattering length of hydrogen means that SLD of H-1 -containing materials is much lower resulting in strong contrast with toluene-d(8). Thus, SANS makes it possible to study the size and shapes of modified buckyballs. This paper describes the first results on cyclohexane-substituted fullerenes.