Material Properties with Syntheses and properties of a novel unsymmetrical photochromic diarylethene

A novel unsymmetrical diarylethene derivative bearing thiophene moieties, in which a methyl group was substituted at the ortho-positions of the terminal phenyl ring, was synthesized. At the same time, its photochromic properties and fluorescence switch were investigated in detail. The results showed that this compound exhibited reversible photochromism, undergoing reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light both in solution and in PMMA film,and its absorption maxima were observed at 556 nm in hexane and at 560 rim in PMMA amorphous film, respectively, upon irradiation with 297 nm UV light. The fluorescence intensity of diarylethene decreased dramatically along with the photochromism from open-ring isomer to closed-ring isomer upon irradiation with 297 urn UV light in PMMA.