A series of 4-(4-n-heptoxy-2,3-difluorophenylethynyl)phenyl 3-nitro-4-polyf
luoroalkoxybenzoate liquid crystals was synthesized and their phase transit
ion behaviours were studied by optical polarizing microscopy and DSC. The r
esults show that the mesogens containing long polyfluoroalkoxy chain tend t
o exhibit the smectic A phase.