Abstract

Chiral binaphthyl derivatives having two photochromic diarylethene units were synthesized in an attempt to use them as dopants for photoresponsive liquid crystals. These compounds showed thermally irreversible photochromic reactions. The circular dichroism (CD) spectra and the optical rotation values of the derivatives reversibly changed in methanol upon alternate irradiation with ultraviolet and visible light. Large photostimulated pitch changes of chiral nematic K-15 liquid crystals were observed on addition of the derivatives as dopants. The relation between the optical rotation and the twisting power force was discussed.