Laterally fluorinated phenyl biphenylcarboxylates; versatile components for ferroelectric smectic C mixtures

Twenty-six fluoro-substituted 4-n-alkoxyphenyl 4'-n-alkyi-and 4'-n-alkoxybiphenyl-4-carboxylates are reported. The number and position of the fluoro groups influences the liquid crystal phase sequence and has a dramatic effect on the liquid crystal transition temperatures. Some compounds have low melting points and a very wide smectic C phase, whereas other compounds exhibit a very wide smectic A phase. Compounds containing a 2,3-difluorophenyl group provide useful materials which have a large negative dielectric anisotropy.