Liquid crystalline compounds containing a biphenyl core

摘要

A compound of formula (I) or a dimer thereof; where R¹ and R² are independently selected from optionally substituted alkyl, optionally substitituted alkenyl, optionally substituted alkynyl, a functional group or a group of sub-formula (i) -(O)_m-(CH₂)_p-R⁷ (i) where m is 0 or 1; p is an integer of from 1 to 12; R⁷ is a group of formula -C_qX_2q+1 where q is an integer of from 1 to 12 and X is halogen such as fluoro, or R⁷ a group of sub-formula (ii) where k is an integer of from 1 to 10, R⁸, R¹⁰, and R¹² and each R⁹ and R¹¹ are independently selected from alkyl, alkenyl or aryl, such as lower alkyl and in particular methyl; provided that at least one of R¹ or R² is a group of sub-formula (i); R³, R⁴, R⁵ and R⁶ are independently selected from hydrogen or halogen, and in particular fluorine, n is 0 or 1, and A is a ring structure as specified. Compounds of formula (I) may have liquid crystal properties and/or be useful in liquid crystal devices.