Photoswitching of Helical Twisting Power of a Chiral Diarylethene Dopant:  Pitch Change in a Chiral Nematic Liquid Crystal

Abstract

A chiral cyclohexane containing two photochromic diarylethene units was synthesized in an attempt to use it as a dopant for a photoresponsive liquid crystal. A stable photoswitching between nematic and cholesteric phases could be induced by the addition of a small amount of the chiral cyclohexane to a nematic liquid crystal 4-cyano-4‘-penthylbiphenyl (K-15).