Synthesis And Photochromic Properties Of Fulgide

Photochromic compounds have attracted considerable attention because of their potential application to photonic devices, such as optical memories and switches. Considerable efforts have been devoted to the development of photochromic compounds such as diarylethenes, fulgides, spiropyrans and spirooxazines. Among of them, fulgides are the most promising candidates for the application because of their thermally irreversible and fatigue-resistant photochromic performance.The main purpose of this paper is to synthesize novel photochromismfulgides and study the photochromic properties of these compounds. Twoaspects were included in this paper:1. Using substituted succinate as starting material, indolfulgide, 3-(3,5-dimethoxybenzylidene)-dihydro-4-substituted-furan-2,5-dione and 3-(benzo[d][1,3]dioxol-5-ylmethylene)-4-substituted-dihydrofuran-2,5-di one were synthesized by Stobbe condensation reaction. The structures of the products were confirmed by IR, ¹H NMR, ¹³C NMR and MS. The structures of 3-(benzo[d][1,3]dioxol-5-ylmethylene)-4-(pentan-3-ylidene) dihydrofuran-2,5-dione (18b) and 3,4-bis(benzo[d][1,3]dioxol-5-ylmethylene)dihydrofuran-2,5-dione (20) were confirmed also by X-ray. 2. We studied the photochromic properties of fulgides. The photochromic experiments results showed that indolfulgides exhibit thermally irreversible photochromic reactions, but3-(3,5-dimethoxybenzylidene)-dihydro-4-substituted-furan-2,5-dione and 3-(benzofd][1,3]dioxol-5-ylmethylene)-4-substituted-dihydrofuran-2,5-di one have no photochromic property.In conclusion, We synthesized a series of novel fulgides and studied the photochromic properties.