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

Small-angle neutron scattering (SANS) has been shown to be an appropriate technique for the structural characterization of fullerenes (1) in solvents with strong SANS contrast (e.g. CS{sub 2}) and we have extended initial studies of C{sub 60} (1) to include C{sub 70} and C{sub 84} moieties. Deuterated solvents (e.g. toluene-d{sub 8}) have a high scattering length density (SLD), which is close to that of C{sub 60}, so there is virtually no SANS contrast with the solvent. Hence, these particles are practically {open_quotes}invisible{close_quotes} in such media, though the negative scattering length of hydrogen means that SLD of H{sup 1}-containing materials is much lower, so they have strong contrast with toluene-d{sub 8}. Thus, SANS makes it possible to study the size and shapes of modified buckyballs and this paper describes the first results on cyclohexane-substituted fullerenes