Chiroptical Switching between Liquid Crystalline Phases

摘要

We have demonstrated that the helically shaped photoswitchable alkenes 1 and 2 are highly effective in the reversible, light-induced, conversion of cholesteric to nematic LC phases as well as in the reversible alteration of the macroscopic helical pitch (and the screw sense) in the cholesteric phase. Both processes in this three-position switch can be controlled by modulation of the diastereomeric ratio that is produced depending on the wavelength used for irradiation. A quantitative study of helical twisting power and wavelength dependency of these processes with other mesoscopic systems is currently in progress.