Indane compounds having negative dielectric anisotropy

Indanes having negative Δε of the formula (Ia) or (Ib)

• 160
• in which:
• R, in each case independently of one another, is an alkyl or alkoxy radical having 1 to 12 carbon atoms which is unsubstituted, monosubstituted by —CF3 or at least monosubstituted by halogen, an oxaalkyl, alkenyl or alkenyloxy radical having 2 to 12 carbon atoms or an oxaalkenyl radical having 3 to 12 carbon atoms, where one or more CH2 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 (—F, —Cl, —Br, —I), —CN, —CH3, —CH2F, —CHF2, —CF3, —OCH3, —OCH2F, —OCHF2 or —OCF3, 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-cyclohexadienylene, in which —CH2— 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 —CH2—CH2—, —CF2CF2—, —CH═CH—, —CF═CH—, —CH═CF—, —C═C—, —CO—O—, —O—CO—, —O—CH2—, —CH2—O—, O—CF2— or a—CF2—O— group,
• X is —H, —F, —Cl, —CN, —NCS, —CF3, —OCF3, —OCHF2,
• Y, V are each, independently of one another, hydrogen, an alkyl, alkoxy, alkenyl or alkinyl radical having 1 to 15 or, respectively, 2 bis 15 carbon atoms which is unsubstituted, mono-substituted by —CF3 or at least monosubstituted by halogen where one or more CH2 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 —CF2— or —CH═ or —CF═ and, in formula (Ib), addition-ally —CH2—
• n, m are each, independently of one another, 0, 1, 2, 3 or 4 and the dofted line is a single bond or a double bond, with the proviso that X in formula (Ib)≠H when W is twice —CH2—.