Studies On Synthesis And Properties Of Liquid Crystalline Compounds Associated 4,4'-Dihydroxydiphenyl Compounds Containing Chiral Carbon

LCD has wider application prospect in high-tech fields, so many researchers are paying great attention to it. Chiral is a common phenomenon in nature and living things. The problems of chiral have great significance for the development of life sciences, pharmaceutical chemistry, (polymer) materials science and other related subjects. The introduction of the chiral dopants in liquid crystal, which greatly promoted the development and applications of new liquid crystal materials and nonlinear optical materials. The LCD which has excellent thermal effects and stable performance has more and more applications in the thermal spectrum image. Chiral liquid crystal materials have been paid more and more attention, which are due to their unique optical properties (such as selective reflection of light, thermochromism, ferroelectric, piezoelectric, etc), so Chiral liquid crystal materials have broad application prospects in the nonlinear optics, rapid light switches, microelectronics and other fields.Two kinds of chiral dopants were synthesized based on L-lactate and Isosorbide respectively, on the basis of them, reacted with United hydroquinone respectively, two novel small molecule thermo tropic liquid crystals were synthesized, the more common routes of synthesis were compared, the experimental factors were discussed, and optimal synthetic route was selected. The structures of compounds were characterized by IR,1HNMR. The relationship between molecular structure and properties were discussed by 341 type polar meter,J-810type circular dichroism instrument and hot stage polarized optical microscopy (POM). The results show that:the four compounds synthesized have good optical properties, The optical properties of two novel chiral liquid crystals will change greatly; we not only get a good mixed results but also not affect the basic performance of the LCD itself when the concentration of chiral dopant was one percent, the chiral liquid crystals do not have black cross extinction phenomenon after reaching clearing point. During the cooling process, the texture of liquid crystal will change more; The properties of Chiral Liquid crystal compounds got improvement comparing with the liquid crystalline in melting point and clearing point, the texture get more changes during the heating process and without significant changes during the cooling process.