Synthesis And Properties Of New Difluorovinyl Tolane Liquid Crystal Comounds

The Liquid Crystal Optical Grating(LCOG)has been greatlyimproved the se years It will demand to be used the 1iquid crystal materialwith high birefringence(0 3≤An≤0 45),low-visco sity,high clearingPoint and fast re sPonse The 1iquid crystal material can be used as thevisible and near infrared 1ight and laser wave frequencY correctionadaptive optic s system In recent years,LCOG has been greatly improvedThe se currently liquid crystal material used in LCOG．the An value is le s sthan 0 2,the re sPonse speed is slow-,the length range of contr011ed waveis relatively narrow-,slow-efficiency of light energy utilization anddependence on the temperature Because of the se drawbacks,it cannotsatisfy the corrector with the wide band static s According toliterature,the liquid crystal compounds with difluoroVinyl has excellentphotoelectricity propertie s and low-visco sity,and tolane conjugatedstructural has high birefringence There are good pro spects in the liquidcrystal compounds In order to develop high birefringence,low-ervisco sity,improve re sponse time(<3ms),meet the requirement for fastbroadband technologY LCD correction performance s,and solve problemsof our near-infrared adaptive optic s and laser wave frequency correctionsystem This paper studie s on the difluoroVinyl tolane 1iquid crystal s,which has high birefringence,10w-vi sco sity,high stability through de sign,synthe si s,purification and propertie s In this way we will solve theproblem that low-vi sco sity and high birefringence of liquid crystalgratingThis Paper de signs and synthe size s nPUTPVF．nUTPVF and nPTPVFthree serie s of 12 target compounds All of them are not reported yet Thestructure s of the se compounds were confirmed by'HNMR,"CNMR,''FNMR,MS,IR and elemental analy sis The birefringence of nPUTPVF An Value s 1s more than 0 4:nU l PVF 1S between 0 19-0 2 and nPl PVF 1Sbetween 0 20-0 27 AcCOrding to their phase transition temperaturemeasured by differential SCanning calorimetry(DSC),it show-s that thenPUTPVF has a high clearing point(>210℃,and a wide nematic phasetemperature range (> 128℃)；the clearing point of nUTPVF is below-50℃and the nematic phase temperature is le s s than 12℃:the clearingpoint of the nUTPVF is between 80-1 00℃and the nematic phasetemperature range is 20-40℃When the visco sity is measured at differenttemperature S．the effect is very ideal...