Cyclohexadiene fullerene derivatives

A compound of formula I

• wherein
• Cn is 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,
• R1, R2, R3, R4 independently of each other denote H, halogen, CN, R5 or R6,
• R5 denotes 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 R6,
• R6 denotes 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 each 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 each optionally replaced by F, Cl, Br, I or CN,
• Y1 and Y2 denote independently of each other H, F, Cl or CN, and
• R0 and R00 denote independently of each other H or an optionally substituted carbyl or hydrocarbyl group with 1 to 40 C atoms,
• wherein at least one of R1, R2, R3 and R4 denotes R5 that is substituted by one or more groups R6 as defined above, which have at least 3 C atoms wherein at least one CH2 group is optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR0—, —SiR0R00—, —CF2—, —CHR0═CR00—, —CY1═CY2— or —C≡C—.