Cyanostilbenes

Compound according to the general formula (I)

• wherein
• Ar1 is phenylene which is unsubstituted;
• Ar2 is phenylene or biphenylene which is unsubstituted or substituted by R1, R2 and R3;
• and wherein:
• if X is hydrogen and Y is CN,
• then R1, R2 or R3 are independently from each other hydrogen or —CF3, with the proviso
• that R1, R2 or R3 are not simultaneously hydrogen;
• if X is CN and Y is hydrogen;
• then R1, R2 or R3 are independently from each other hydrogen or —CF3;
• M is a single covalent bond or a straight-chain or branched alkylene residue having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 carbon atoms, which is unsubstituted, mono-substituted by cyano or halogen, or poly-substituted by halogen and wherein one or more, CH2 groups independently may be replaced by a heteroatom or a group selected from —O—, —CO——CO—O—, —O—CO—, —NR1′—, —NR1′—CO—, —CO—NR1′—, —NR1′—CO—O—, —O—CO—NR1′—, —NR1′—CO—-NR1′—, —C═C—, —C≡C—, —O—CO—O—and —Si(CH3)2—O—Si(CH3)2—, wherein R1′ is a hydrogen atom or lower alkyl;
• Y1 is —O—;
• Y2 is single bond, —O—, —CO—, —COO— or —OCO—;
• P is a hydrogen atom, optionally substituted alkyl, or a polymerizable group, which is selected from acrylate, methacrylate, vinyl ether and ester, epoxy, styrene derivatives, siloxanes, imide monomers, amic acid monomers and their corresponding polymers, homo or copolymers.