3-(4-Bromophenyl)-5-(4-hydroxyphenyl)isoxazole: a versatile, new molecular building block for side-chain liquid crystal oligomers and polymers

摘要

The synthesis and liquid crystalline behaviour of new comb-shaped methacrylate oligomers, derived from a new key intermediate in the synthesis of heterocyclic liquid crystals, i.e., 3-(4-bromophenyl)-5-(4-hydroxyphenyl)isoxazole, are reported. These new thermotropic liquid crystals exhibit a smectic A mesophase (SmA) above a soft crystal phase (CrE). The new methacrylate oligomers were synthesized by free radical polymerization of the corresponding monomers. Additionally, one main-chain liquid crystal polymer (MCLCPs) was prepared using a Mizoroki-Heck polymerization.