Patent ID: 8304036

Claim:
A compound of formula I in which Y denotes Se or Te, L 1 and L 2 each, independently of one another, denotes H, halogen, CN, CF 3 or an alkyl group having 1 to 5 C atoms, R 1 and R 2 each, independently of one another, denotes F, Cl, —CN, —NCS, —SF 5 , —CF 3 , —CHF 2 , —CH 2 F, —OCF 3 , —OCHF 2 , —OCH 2 F or an alkyl group having 1 to 15 C atoms, which may optionally be monosubstituted by CN or at least monosubstituted by halogen, in which one or more CH 2 groups may each be replaced, independently of one another, by —O—, —S—, —CH═CH—, —CF═CF—, —CF═CH— or —CH═CF— in such a way that neither O nor S atoms are linked directly to one another, or a polymerizable group, each, independently of one another, denotes (a) a trans-1,4-cyclohexylene radical, in which one or two non-adjacent CH 2 groups may be replaced by —O— and/or —S—, (b) a 1,4-cyclohexenylene radical, (c) a 1,4-phenylene radical, in which one or two non-adjacent CH groups may be replaced by N, (d) a radical selected from the group consisting of naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl and indane-2,5-diyl, (e) a radical selected from the group consisting of 1,3-cyclobutylene, 1,4-bicyclo[2.2.2]octylene, 1,3-bicyclo[1.1.1]-pentylene and spiro-[3.3]-heptane-2,6-diyl, or (f) a radical selected from the group consisting of the following formulae and their minor images in which hydrogen atoms may be mono- or polysubstituted by F, Cl, CN, NCS, SF 5 , CH 2 F, CHF 2 , CF 3 , OCH 2 F, OCHF 2 or OCF 3 , and one or more double bonds may be replaced by single bonds, M, M 1 and M 2 each, independently of one another, denotes —O—, —S—, —CH 2 —, —CHY— or —CY′Y 2 — in such a way that adjacent groups do not simultaneously denote —O— or —S—, Y 1 and Y 2 each, independently of one another, denotes Cl, F, CN, OCF 3 or CF 3 , wherein in (a) and (b), one or more H atoms may be replaced, independently of one another, by F, and in (b), (c) and (d), one, two or three —CH═ groups may each be replaced, independently of one another, by a group selected from the group consisting of —CF═, —CCl═, —CBr═, —C(CN)═, —C(CH 3 )═, —C(CH 2 F)═, —C(CHF 2 )═, —C(OCH 3 )═, —C(OCHF 2 )═ and —C(OCF 3 )═, and one or more —CH 2 — groups may be replaced by —CF 2 —, Z 1 and Z 2 each, independently of one another, denotes a single bond, —CH 2 —CH 2 —, —CF 2 —CH 2 —, —CH 2 —CF 2 —, —CF 2 —CF 2 —, —CHF—CHF—, —CH 2 —CHF—, —CHF—CH 2 —, —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —C≡C—, —(CO)O—, —O(CO)—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 — or a combination of two of these groups, where no two O atoms are connected to one another, n denotes 0, and m denotes 0, 1, 2, 3 or 4, with the proviso that compounds wherein n=0, m=1, Z 2 =a single bond, A 2 =1,4-phenylene and R 2 ═CN, or OH are excluded, and with the proviso that compounds having the following formula are excluded