Photochromic diarylethene derivatives containing 2,4-diphenylphenyl substituents form stable amorphous solids and exhibit reversible photochromism in the solid state. Refractive indices of the amorphous films changed reversibly with the photochromic reactions as much as Δn = 0.028 at 817 nm.
Photochromic diarylethene derivatives containing 2,4-diphenylphenyl substituents formedstable amorphous solids and showed reversible solid-state photochromism. Refractive indicesof the amorphous films changed reversibly with the photochromic reactions as much as Δn= 0.028 at 817 nm. Changes in both absorption band and static polarizability contributedto the large refractive index modulation.