Reactive mesogenic azulenes

A reactive mesogenic azulene compound of the formula I

• P—Sp—T—R1 I
• wherein
• P is CH2═CW1—COO—,
• CH2═CW2—(O)k1—, CH3—CH═CH—O—, HO—CW2W3, HS—CW2W3, HW2N—,HO—CW2W3—NH—, CH2═CW1—CO—NH—, CH2═—CH—(COO)k1—Phe—(O)k2—, Phe-CH═CH—, HOOC—, OCN— and W4W5W6 Si—, with W1 being H, Cl, CN, phenyl or alkyl with 1 to 5 C-atoms, W2 and W3 being independently of each other H or alkyl with 1 to 5 C-atoms, W4, W5 and W6 being independently of each other Cl, oxaalkyl or oxacarbonylalkyl with 1 to 5 C-atoms, Phe being 1,4-phenylene and k1 and k2 being independently of each other 0 or 1,
• Sp is a single bond or a linear or branched alkylene group having 1 to 20 C atoms, in which one or more non-adjacent CH2 groups are optionally replaced by —O—, —S—, —NH—, —N(CH3)—, —CO—, —O—CO—, —S—CO—, —O—COO—, —CO—S—, —CO—O—, —CH(halogen)—, —C(halogen)2, —CH(CN)—, —CH═CH— or —C≡C—, or a siloxane group,
• R1 is H, halogen, CN, NO2, an aliphatic, alicyclic or aromatic group with up to 40 C atoms that optionally comprises one or more hetero atoms and one or more fused rings, or a group P—Sp—, and
• T is a mesogenic group of the formula II
• —Z1—(A1—Z2)m—(T1—Z3)n—(A2—Z4)o— II
• wherein
• A1 and 2 are independently of each other an aromatic or heteroaromatic group with up to 18 C atoms which is unsubstituted, mono- or polysubstituted with R1, and A1 may also denote T1,
• Z1 to Z4 are independently of each other —O—, —S—, —CO—, —COO—, —OCO—, —O—COO—, —CO—NR0—, —NR0—CO—, —OCH2—, —CH2O—, —SCH2—, —CH2S—, —CF2O—, —OCF2—, —CF2S—, —SCF2—, —CH2CH2—, —CF2CH2—, —CH2CF2—, —CF2CF2—, —CH═N—, —N═CH—, —N═N—, —CH═CR0—, —CX1═CX2—, —C≡C—, —CH═CH—COO—, —OCO—CH═CH—or a single bond,
• X1 and X2 are independently of each other H, F, Cl or CN,
• T2 is a group consisting of 1,2,3, or 4 azulene groups which are optionally substituted by R2,
• R2 is H, halogen, CN, NO2, 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, wherein one or more non-adjacent CH2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NH—, —NR0 —, —SiR0R00—, —CO—, —COO—, —OCO—, —OCO—O—, —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, or denotes an aromatic or heteroaromatic group or a group P—Sp,
• R0 and R00 are independently of each other H or alkyl with 1 to 12 C-atoms,
• m and o are independently of each other 0, 1, 2 or 3, and
• n is 1, 2or3.