Anisotropic compounds with negative or positive DC-anisotropy and low optical anisotropy

Abstract

Anisotropic compounds with negative or positive DCA and .DELTA.n.ltoreq.0.2 have the formula (1) ##STR1## in which R.sup.1 and R.sup.2 l are independently hydrogen, alkyl, alkoxy having 1 to 12 carbon atoms respectively, or one of R.sup.1 and R.sup.2 can represent cyclical fragment of formulae (1a) or (1b); ##STR2## the bridges Z.sup.1, Z.sup.2 and Z.sup.3 are identical or different and means covalent bonds or carboxyl or oxycarbonyl groups; R.sup.3 is hydrogen, alkyl or alkoxy group having 1 to 12 carbon atoms, respectively; X.sup.1 and X.sup.4 are independently hydrogen, halogen, nitrile or nitro, wherein at least one of X.sup.1 and X.sup.4 is not hydrogen when R.sup.2 represents a cyclical fragment of formula (1a) or (1b) and Z.sup.2 is a carboxyl group or Z.sup.3 is an oxycarbonyl group, respectively. Liquid crystal compositions are also disclosed.

Dependencies are inferred from the claim text.