A rational synthesis of polyacrylates with discogenic side groups

Abstract

The ferric chloride mediated oxidative coupling of 3,3,4,4-tetrahexyloxybiphenyl with 2-hexyloxyanisole followed by demethylation gave 3,6,7,10,11-pentahexyloxy-2-hydroxyor triphenylene. Reaction with tert -butyldimethylsilyl-protected 6-bromohexanol, removal of the protecting group, and condensation with acryloyl chloride methacryloyl chloride gave acrylate and methacrylate monomers with hexamethylene 'spacers'. Alternatively, reaction of 3,6,7,10,11-pentahexyloxy-2-hydroxytriphenylene with 2-(2-chloroethoxy)ethanol followed by acryloyl chloride or methacryloyl chloride gave acrylate and methacrylate monomers with diethylenoxy 'spacers'. Both of the poly(acrylate) homopolymers and the poly(methacrylate) homopolymer with the diethylenoxy 'spacer' gave columnar liquid crystal phases. This is contrary to the current perception that the methacrylate polymer backbone is too inflexible to be incorporated in columnar phases.