Liquid crystal compounds containing chiral 2-halo-2-methyl ether and

Abstract

This invention provides chiral nonracemic compounds of general formula I which are useful as components of FLC compositions in SSFLC and DHFLC devices: ##STR1## wherein Z is a C.dbd.O group or a CH.sub.2 group, R.sub.F is a partially or fully fluorinated alkyl or alkenyl group, R.sub.2 is selected from an alkyl, alkenyl or alkynyl group in which one or more CH.sub.2 groups can optionally be substituted with one or two halogen atoms or in which one or more non-neighboring CH.sub.2 can be replaced with an O, S or an alkyl silyl group, S.sub.1 (R.sub.A)(R.sub.B), in which R.sub.A and R.sub.B, independently of one another, are small alkyl or alkenyl groups having from one to six carbon atoms, * indicates the chiral carbon and where Ar can be a one, two, or three aromatic ring LC core moieties. In particular, the core can have one to three, aromatic rings which are optionally linked by linking groups including O, S, CH.sub.2 S, SCH.sub.2, CH.sub.2 CH.sub.2, CH.sub.2 O, OCH.sub.2, CH.sub.2 CO.sub.2, CH.sub.2 OCO, COO, OOC, COS, a double or a triple bond and can contain cyclohexyl cyclohexenyl rings which are optionally substituted or which contain O atoms in the ring.