Patent ID: 7122228

Claim:
A compound having negative Δε of the formula (Ia) or (Ib) wherein: R, in each case independently of one another, is an alkyl or alkoxy radical having 1–12 carbon atoms which is unsubstituted, monosubstituted by —CF 3 or at least monosubstituted by halogen, an oxaalkyl, alkenyl or alkenyloxy radical having 2–12 carbon atoms or an oxaalkenyl radical having 3–12 carbon atoms, where one or more CH 2 groups in these radicals may also, in each case independently of one another, be replaced by —O—, —S—, —CO—, —COO—, —OCO— or —OCO—O— in such a way that heteroatoms are not linked directly to one another, A, in each case independently of one another, is 1,4-phenylene, in which ═CH— may be replaced once or twice by ═N— and which may be mono- to tetrasubstituted, independently of one another, by halogen, —CN, —CH 3 , —CH 2 F, —CHF 2, —CF 3, —OCH 3, —OCH 2 F, —OCHF 2 or —OCF 3, 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-cyclohexadienylene, in which —CH 2 — may be replaced once or twice by, independently of one another, —O— or —S— and which may be mono- or polysubstituted by halogen, Z, in each case independently of one another, is a single bond, a —CH 2 —CH 2 —, —CF 2 CF 2 —, —CH═CH—, —CF═CH—, —CH═CF—, —C≡C—, —CO—O—, —O—CO—, —O—CH 2 —, —CH 2 —O—, O—CF 2 — or a —CF 2 —O— group, X is —F, —Cl, —CN, —NCS, —CF 3, —OCF 3, or —OCHF 2, Y, V each is, independently of one another, hydrogen, or alkyl having 1–15 carbon atoms, alkoxy having 2–15 carbon atoms, alkenyl having 2–15 carbon atoms, or alkynyl having 1–15 carbon atoms, which is unsubstituted, monosubstituted by —CF 3 or at least monosubstituted by halogen where one or more CH 2 groups in these radicals may also, in each case independently of one another, be replaced by —O—, —S—, —CO—, —COO—, —OCO— or —OCO—O— in such a way that heteroatoms are not linked directly to one another, Y is additionally —F or —Cl, W, in each case independently of one another, is —O—, —C(O)—, —CHF— or —CF 2 — or —CH═ or —CF═ and, in formula (Ib), additionally —CH 2 — n, m each is, independently of one another, 0, 1, 2, 3 or 4 and the dotted line is a single bond or a double bond, with the proviso that n in formula (Ia) is 1. 2, 3, or 4.