Study On Synthesis Of New Liquid Crystal Compounds Containing Trans Decalin-group

Synthesis of new liquid crystal compounds containing trans decalin wasstudied,and fluorinated liquid crystals containing trans decalin with differentstructureswere designed as well.Two liquid crystal compounds with superiorperformance were synthesized by2-isonaphthol as basic materials.Novel trans-decalinderivative shows the excellent optical characters such as lower thresholdvoltage,increasing dielectric anisotropy and decreasing birefringence in liquid crystalcomposition.It is especially useful as a liquid crystal for TFT driving.This thesis consists of the following four parts:Part one, the relationship between the properties and molecular structure of theliquid crystal was discussed.The effect on the performance of liquid crystal mixturewith liquid crystal compounds containing trans decalin-group was reviewed.Part two, the intermediate6-propyl-2-isonaphthol was synthesized via reactions of2-isonaphthol with phenolichydroxylgroupmethoxylation, Friedel-Crafts reaction,Wolff-Kishner-Huang reaction and acylationdemethylation.This compound wasidentified by GC-MS, IR and1HNMR.Part three, the intermediate6-propyl-2-decalone was synthesized via reactions of6-propyl-2-isonaphthol with hydrogenation reaction and Jones oxidation reaction.Thiscompound was identified by GC-MS, IR and1HNMR. It was discussed that the effecton configuration of2,6-substituted decalinof hydrogenation conditions. theconfiguration of dominant product was confirmed according to the analysis conditionsPart four, the target compounds were synthesized via reactions of mixture6-propyl-2-decalone and substituted benzene by the coupling reaction with lithium reagent, dehydration and hydrogenation reactions. Two compounds were synthesizedas follow:6-propyl-2-(3’,4’,5’-trifluoro-1’,1"-biphenyl)trans decalin and6-propyl-2-(2’,3’-difluoro-4’-ethyoxylphenyl) trans decalin.These compounds were identified by GC,GC-MS,IR and1HNMR.