Fullerene derivatives

A compound of formula I

• wherein
• Cn denotes a fullerene composed of n carbon atoms, optionally with one or more atoms trapped inside,
• Adduct is a secondary adduct, or a combination of secondary adducts, appended to the fullerene Cn with any connectivity,
• m is 0, an integer>1, or a non-integer>0,
• o is an integer≥1,
• ArS1 denotes an aryl or heteroaryl group with 5 to 20, preferably 5 to 15, ring atoms, which is mono- or polycyclic,
• R1 to R6 denote, independently of each other, H, halogen, CN, R7, R8 or R9,
• R7 denotes, on each occurrence identically or differently, a saturated or unsaturated, non-aromatic carbo- or heterocyclic group, or an aryl, heteroaryl, aryloxy or heteroaryloxy group, wherein each of the aforementioned groups has 3 to 20 ring atoms, is mono- or polycyclic, does optionally contain fused rings, and is optionally substituted by one or more halogen atoms or CN groups, or by one or more identical or different groups R8 or R9,
• R8 denotes, on each occurrence identically or differently, an alkyl group with 1 to 30 C atoms, which is straight-chain, branched or cyclic, and in which one or more CH2 groups are optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR0—, —C(═O)NR0—, —NR0—C(═O)—, —SiR0R00—, —CF2—, —CHR0═CR00—, —CY1═CY2— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, Br, I or CN,
• R9 denotes, on each occurrence identically or differently, a straight-chain, branched or cyclic alkyl group with 1 to 50, preferably 2 to 50, more preferably 2 to 25, most preferably 2 to 12, C atoms, in which one or more CH2 or CH3 groups are replaced by a cationic or anionic group,
• Y1 and Y2 denote, independently of each other, H, F, Cl or CN,
• R0 and R00 denote, independently of each other, H or an optionally substituted carbyl or hydrocarbyl group having 1 to 40 C atoms,
• with the provisos that
• a) at least one of R1, R2, R3 and R4 is different from H, and
• b) if n=70, then R1 is different from —C(═O)—O—CH3 if R2 is H, and R2 is different from —C(═O)—O—CH3 if R1 is H, and
• wherein when R1 , R2, R3 and R4 are different from H, they are selected from the following formulae
• wherein
• ArS2 denotes R7 or has one of the meanings of ArS1,
• i is 0 or an integer from 1 to 9,
• k is 0 or an integer from 1 to 9.