Fluoroalkylfluorene derivatives

A compound of Formula (I)

• D-S1-A-S2—B1, Formula (I)
• wherein:
• A represents —Ar1-(FL-Ar2)n- and comprises from 1 to 8 FL groups;
• Ar1 and Ar2 in each occurrence are independently selected from the group comprising Ara and a bond;
• Ara represents a diradical comprising 1 aromatic, heteroaromatic or FL moiety, or 2, 3, 4 or 5 aromatic, heteroaromatic and/or FL moieties mutually connected by a single bond;
• n is an integer from 1 to 8;
• FL is a fluorene moiety of the structure
• incorporated into the chain through covalent bonds at C-2 and C-7;
• the R groups of each FL moiety are identical and are selected from the group consisting of straight chain or branched achiral C1-C14 alkyl, C1-C14 haloalkyl, C1-C14 fluoroalkyl, C2-C14 alkenyl group, optionally wherein 1, 2, 3, 4 or 5 CH2 groups are replaced by an oxygen provided that no acetal, ketal, peroxide or vinyl ether is present in the R group;
• D represents a cross linkable group or, when B1 represents a hydrogen, D represents —B2—S3—B3—S1a-A-S2a—B1a, —S3(B2)—B3—S1a-A-S2a—B1a, —S3(B2)(B3)—S1a-A-S2a—B1a, —S3(B2)(B3), or a cross linkable group wherein the dash at the left-hand end of the chain represents the point of attachment to S1;
• B1 represents a cross linkable group or a hydrogen atom;
• B1a represents a cross linkable group or a hydrogen atom;
• B2 and B3 each represents a cross linkable group;
• S1, S2, S1a and S2a are flexible linker groups;
• and
• S3 is a spacer group.