Mono-, oligo-and polyalkylidenefluorenes and their use as charge transport materials

A compound of formula I

• R9—[(A)a—(B)b—(C)c]n—R10 I
• wherein
• A and C are independently of each other —CX1═CX2—, —C≡C—, optionally substituted arylene, or optionally substituted heteroarylene,
• X1 and X2 are independently of each other H, F, Cl or CN,
• B is a group of formula II
• R1 and R2 are independently of each other halogen, optionally substituted aryl, optionally substituted heteroaryl, P—Sp—X, or straight chain, branched or cyclic alkyl with 1 to 20 C-atoms, which is unsubstituted, mono- or poly-substituted by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH2 groups can be replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR0—, —SiR0R00—, —CO—, —COO—, —OCO—, —OCO—O—, —SO2—, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
• R3 to R10 are independently of each other H, halogen, optionally substituted aryl, optionally substituted heteroaryl, P—Sp—X, or straight chain, branched or cyclic alkyl with 1 to 20 C-atoms, which is unsubstituted, mono- or poly-substituted by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH2 groups can be replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR0—, —SiR0R00—, —CO—, —COO—, —OCO—, —OCO—O—, —SO2—, —S—CO—, —CO—S—, —CH═CH— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
• R0, R00 are independently of each other H or alkyl with 1 to 12 C-atoms,
• P is a polymerisable or reactive group,
• Sp is a spacer group or a single bond,
• X is —O—, —S—, —OCH2—, —CH2O—, —CO—, —COO—, —OCO—, —OCO—O—, —CO—NR0—, —NR0—CO—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CH═CH—COO—, —OOC—CH═CH— or a single bond,
• a, b, c are independently of each other 0 or 1, with a+b+c>0, and wherein in at least one recurring unit [(A)a—(B)b—(C)c] b is 1, and
• n is an integer ≧1,
• wherein the recurring units [(A)a—(B)b—(C)c] can be identical or different, and
• with the provisos that
• a) in case n is 1, a and c are 0, R3-8 are H, and one of R1 and R2 is methyl and the other is methyl, ethyl or phenyl, R9 and R10 are not at the same time Cl or Br, and
• b) A and C are different from 2,7-(4-hexylphenyl)fluorene-9-carbonyl.