ALPHA-HYDROXY CARBOXYLIC ACID DERIVATIVES SUITABLE FOR USE IN LIQUID CRYSTAL MATERIALS AND DEVICES

摘要

Compounds which may be used as a dopant or host in a ferroelectric chiral smectic liquid crystal mixture. The compounds are characterised in that they are derivatives of an X-hydroxy carboxylic acid and contain the chiral unit (I), in which Ro may be alkyl, alkoxy, halogen, formula (II), where b may be 0 to 3 and the phenyl ring may be substituted, and a is 0 or 1. The chiral unit is combined with a range of mesogenic combinations of groups. Lactic acid derivatives are described in detail (i.e. Ro = methyl) together with various preparative routes, for example the compound formula (III), which has dopant properties in a range of hosts.