Refractive Index Change of Dithienylethene in Bulk Amorphous Solid Phase

Abstract

A diarylethene derivative, 1,2-bis(5-(4- tert -butylphenyl)-2,4-dimethylthiophen-3-yl)- 3,3,4,4,5,5-hexafluorocyclopentene, forms stable amorphous solid with T g of 68°C. Reversible photochromism in the amorphous solid film is observed upon alternate irradiation with UV ( e.g. 313 nm) light and visible (580 nm) light. The refractive index of the solid film changed by as much as 3.8×10 -2 along with the photoisomerization.