126334-33-6Relevant articles and documents
The synthesis and electro-optic properties of liquid crystalline 2- (2,3-difluorobiphenyl-4'-yl)-1,3-dioxanes
Dong, Chu Chuan,Styring, Peter,Goodby, John W.,Chan, Lawrence K. M.
, p. 1669 - 1677 (2007/10/03)
Fifty-six novel alkyl and/or alkoxy disubstituted 2-(2,3- difluorobiphenyl-4'-yl)-1,3-dioxanes (DFBPD) were prepared. Smectic C and nematic mesophases were exhibited by most of the alkyl-alkoxy homologues. Conversely, most of the dialkyl compounds exhibited smectic C, smectic A and nematic phases. The birefringence (Δn), dielectric anisotropy (Δε), spontaneous polarisation and response times of two ferroelectric mixtures formulated from the dioxanyl systems were determined. The birefringence results were compared with eight other groups of mixtures where the materials were based on different core systems. The overall electro-optic properties of the DFBPDs were found to be comparable to the best of the eight most commonly used materials in ferroelectric display devices.
The Synthesis and Transition Temperatures of Some 4,4"-dialkyl- and 4,4"-Alkoxyalkyl-1,1':4',1"-terphenyls with 2,3- or 2',3'-difluoro Substituents and of their Biphenyl Analogues
Gray, George W.,Hird, Michael,Lacey, David,Toyne, Kenneth J.
, p. 2041 - 2054 (2007/10/02)
The tetrakis(triphenylphosphine)palladium(o)-catalysed coupling of arylboronyc acids with aryl halides is used to prepare several 4,4"-dialkyl- and 4,4"-alkoxyalkyl-1,1':4',1"-terphenyls with 2,3- or 2',3'-difluoro substituents and their related biphenyl systems.Lithiation ortho to a 1,2-difluoroaromatic unit provides the route to the 2,3-difluoroarylboronic acids.The 2,3-difluoro substituted terphenyls are low-melting liquid crystals with wide-range Sc phases and no underlying smectic phase; these compounds are excellent hosts for ferroelectric systems.The compounds with widest Sc ranges are those with the difluoro substituents in an end ring and the compounds with difluoro substituents in the central ring show more nematic character and so are useful for ECB devices.