Synthesis of polyfluorinated polycyano negative dielectric anisotropy liquid crystalline compounds

In order to meet the different demands of the LCD,two novel polyfluorinated polycyano negative dielectric anisotropy liquid crystalline compounds were synthesized.These compounds were synthesized from phthalonitrile and 1,2-difluorobenzene by several steps.Their constructions were confirmed by NMR and elemental analysis.The parameters and the performances of these products were measured by POM,DSC and rotary viscometer.These polyfluorinated polycyano compounds have small optical anisotropy(Δn=0.096~0.107),large negative dielectric anisotropy(Δe=-15.2~-16.7)and high viscosity(γ1= 234.8~248.6mPa·s).These compounds can be used in the LCDmatrix to improve partial performance of the LCD.The preparation method is of simple operation and low cost,which can also realize industrialization easily.