We have previously reported that cholesteric liquid crystals doped with chiral azobenzene molecules show different HTP(Helical Twisting Power)trans-form or cis-form of azobenzene groups.Binaphthyl derivatives are well known as one of chiral molecules exhibiting high HTP.In addition it is reported that HTP of a chiral molecule having an ester bond depends on the direction of the ester bond and the length of the molecule.In this study,we tried to design and synthesize various binaphtyl chiral derivatives combining azobenzene and biphenyl groups,and investigated the effect of the ester bonding direction to the binaphtyl group on the HTP and photoisomerization rate
