ORIENTATIONAL ORDER OF P-N-ALKOXYBENZYLIDENE-P'-FLUOROANILINES - X-RAY-DIFFRACTION AND ELECTROOPTIC RESPONSE OF THE CHIRAL (S)-P-2-METHYLBUTYLOXY DERIVATIVE

This work continues our study of the mesomorphic properties of the p-n -alkoxybenzylidene-p'-fluoroanilines. Previous studies have shown that the straight chain homologues, with the number of carbon atoms in the chain ranging from 4 to 8, form smectic phases. In this paper we desc ribe H-2 NMR studies of the homologues with n = 4, 5 and 8 and the syn thesis and properties of a chiral branched chain derivative, S)-p-2-me thylbutyloxybenzylidene-p'-fluoroaniline. This compound is not mesomor phic, but does show solid state polymorphism. From an optical, electro -optical, DSC and X-ray diffraction study we infer that the higher tem perature crystalline form is a CrE phase.