Reentrant phenomena in cyano substituted biphenyl esters containing flexible spacers

摘要: Abstract A number of 4′-substituted phenyl 4-(4′-cyano-4-oxybiphenyl)butanoates have been synthesized to study the effects -O-(CH2)3COO- inter-ring linkage on mesomorphic behaviour. Transition temperatures determined and are compared with those cyanobiphenylmethanoate analogues. In general, butanoates exhibit lower melting points but in all cases, a nematic-isotropic transition is observed. An interesting feature some members butanoate series presence several reentrant mesophases. unique phenomenon observed while studying behaviour one was appearance smectic filaments from isotropic liquid cooling. These filaments, through an unusual process, eventually form typical texture. Formation SA phase or nematic this fashion has not reported previously.