Patent ID: 8303844

Claim:
A compound of the formula I: in which m and n are each, independently of one another, 0, 1, 2 or 3, where m+n≦4; L 1 and L 2 each, independently of one another, denote H, halogen, CN, CF 3 , CHF 2 , CH 2 F or CH 3 ; A 1 and A 2 each, independently of one another, denote (a) 1,4-phenylene, in which ═CH— may be replaced once or twice by ═N— and which may be unsubstituted or mono- to tetrasubstituted, independently of one another, by —CN, —F, —Cl, —Br, —I, C 1 -C 6 -alkanyl which is unsubstituted or mono- or polysubstituted by fluorine and/or chlorine, or C 1 -C 6 -alkoxy which is unsubstituted or mono- or polysubstituted by fluorine and/or chlorine, (b) 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-cyclohexadienylene, in which —CH 2 — may be replaced once or twice, independently of one another, by —O— or —S— in such a way that heteroatoms are not linked directly, and which may be unsubstituted or mono- or polysubstituted by —F and/or —Cl, or (c) bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl or spiro[3.3]heptane-2,6-diyl; Z 1 and Z 2 each, independently of one another, denote a single bond, or a group selected from the group consisting of —CF 2 O—, —OCF 2 —, —CH 2 CH 2 —, —CF 2 CF 2 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —(CO)O—, —O(CO)—, —CH 2 O—, —OCH 2 —, —CF═CH—, —CH═CF—, —CF═CF—, —CH═CH—, and —C≡C—, or a combination of two of said groups groups, where O atoms are not linked directly; R 1 and R 2 , independently of one another, denote hydrogen, an alkanyl, or alkoxy radical having 1 to 15 C atoms, or an alkenyl or alkynyl radical having 2 to 15 C atoms, which alkanyl, alkoxy, alkenyl or alkynyl radical is unsubstituted, monosubstituted by —CN or mono- or polysubstituted by —F, —Cl and/or —Br, in which alkanyl, alkoxy, alkenyl or alkynyl radical one or more CH 2 groups may each be replaced, independently of one another, by —O—, —S—, —SO 2 —, —CO—, —(CO)O—, —O(CO)—or —O(CO)O— in such a way that heteroatoms are not linked directly, or denote —F, —Cl, —Br, —CN, —SCN or —SF 5 ; and ring B denotes one of the following rings where A 1 and A 2 or Z 1 and Z 2 may each have identical or different meanings if m or n is greater than 1, where R 1 and R 2 do not simultaneously denote H, and where in the case where R 1 ═H and m=0 or R 2 ═H and n=0, then ring B denotes a pyran of the formula