DITHIENYLCYCLOPENTENE COMPOUND, STYRENE POLYMER HAVING DITHIENYLCYCLOPENTENE, PHOTOCHROMIC MATERIAL, AND PHOTONIC ELEMENT

摘要

A display material which, upon light irradiation, generates two isomers each relatively stable to heat and which in a colored state can be easily returned to a colorless state; a photochromic material which reacts irreversibly by the action of ultraviolet; a novel photochromic material which assumes a red color; a novel photochromic material which reacts irreversibly by the action of ultraviolet to show photochromism and is irreversibly decolored by heating; and a polymer which in a solid state shows photochromism and which can contain a photochromic ingredient evenly at a high density. The display material is a dithienylcyclopentene compound represented by the following general formula (I). The polymer is a styrene polymer having a dithienylcyclopentene represented by the following general formula (II).