Fullerene derivatives, methods of preparing them and their use

A fullerene derivative of the formula I ##STR49## where the symbols and indices have the following meanings:

• F:
• is a fullerene radical of the formula C.sub.(20+2m) where m=20, 25, 28, 29;
• E.sup.1, E.sup.2 :
• are identical or different and are each COOH, COOR, CONRR.sup.1, CHO, COR, CN, P(O)(OR).sub.2 and SO.sub.2 R, where R, R.sup.1 are each a straight-chain or branched, aliphatic radical (C.sub.1 to C.sub.20) which may be unsubstituted or monosubstituted or polysubstituted by identical or different substituents, in which radical up to every third CH.sub.2 unit can be replaced by O or NR.sup.4, where R.sup.4 is (C.sub.1 -C.sub.20)-alkyl or benzyl, or a benzyl radical or phenyl radical which can be unsubstituted or substituted by from 1 to 5 substituents R, OH, OR, COOR, OCOR, SO.sub.3 H, SO.sub.2 Cl, F, Cl, Br, NO.sub.2 and CN or together are ##STR50## or are different from one another and are each COR, R or H, or are different from one another and are each COR/R or F/Cl/Br, where R is as defined above, or are different from one another and are each NO.sub.2, R.sup.3 or H, where R.sup.3 is an unsubstituted, monosubstituted or polysubstituted aliphatic radical (C.sub.1 to C.sub.20);
• n:
• is a natural number from 1 to 10+m where m=20, 25, 28, 29.