Low Melting Liquid Crysalline Heterocyclc Anils⁽¹⁾

Abstract

Abstract A homologous series of 3-N-(4′-alkoxybenzilideneamino)-6-n-alkylpyridines has been synthesized and compared to the carbocyclic analogs. The pyridine anils exhibit low melting points and generally nematic behavior with much lower thermal nematic stability. The lateral attractive effect of a permanent dipole was exhibited without concomitant interference from the steric interactions which usually accompany an added dipole. The effect of heteroatomic ring position was assessed by comparison to the synthetic 2-N-(4′-alkoxybenzilideneamino)-5-n-alkylpyridine isomers. The role of symmetry in the heterocyclic materials and the influence of an additional permanent dipole was investigated. A simple, rapid, high yield synthesis was developed for making the required intermediate disubstituted pyridines.