New entry for fluorinated carbocycles: Unprecedented 3,6-disubstituted 1,1,2,2-tetrafluorocyclohexane derivatives.

The synthetic protocols for symmetrical/unsymmetrical 3,6-disubstituted 1,1,2,2-tetrafluorocyclohexane molecules were successfully established for the first time. Some of thus obtained tetrafluorinated cyclohexanes underwent recrystallization to afford trans -configured products preferentially. One of the unsymmetrical trans -disubstituted tetrafluorocyclohexanes, trans -1-ethyl-2,2,3,3-tetrafluoro-4-[4-( trans -4- n -propylcyclohex-1-yl)phenyl]cyclohexane, was found to possess a low birefringence Δ n (0.073) and a large negative dielectric anisotropy Δ ε (–9.4) in a binary mixture system, which were very prominent as characteristics of LC molecules in VA-mode driving LC displays. [ABSTRACT FROM AUTHOR]