Gerwald F. Grahe

Design, Synthesis and Physical Properties of New Liquid Crystal Materials Having a Fluoro-Substituted Tetrahydronaphthalene Structure for Active Matrix LCD

Liquid crystal materials having a fluoro-substituted tetrahydro-naphthalene structure were designed for active matrix LCD. 6-Aryl-5-fluoro-1,2,3,4- tetrahydronaphthalenes and 5,6-difluoro-1,2,3,4-tetrahydronaphthalenes were prepared by regioselective fluorination and hydrogenation of 2-naphthols. 6-Aryl-5,7-difluoro-1,2,3,4-tetrahydronaphthalenes were synthesized from 5,7-difluoro-1,2,3,4-tetrahydronaphthalene-2-one. The liquid crystal mixture containing these compounds with very good co-solubility exhibits a wide nematic temperature range with low melting point and very large value of dielectric anisotropy. From these results these compounds are useful for design of new liquid crystal mixtures for TFT-displays.

Design, Synthesis and Physical Properties of New Liquid Crystal Materials for Active Matrix LCD (1): New Saturated Ring Systems Prepared by Stereoselective Hydrogenation as New Mesogens Containing Fluorines

Abstract Liquid crystal materials having a decahydronaphthalene ring structure were designed for active matrix LCD and were prepared by hydrogenation of the ocatahydronaphthalenes obtained through the reaction of a fluorinated phenyl magnesium bromide with the 6-alkyl-decahydronaphthalen-2-ones and followed by dehydration. These compounds exhibit wide nematic temperature ranges with low melting points and very low birefringences. These results are useful for design of new liquid crystal mixtures for TFT-displays.