EFFECT OF 2 ELECTRON-DONATING SUBSTITUENTS ON PHOTOCHROMISM OF ARYL FULGIDE, 2-(2,6-DIMETHYL-3,5-SUBSTITUTED BENZYLIDENE)-3-ISOPROPYLIDENESUCCINIC ANHYDRIDE

Two electron-donating substituents (e.g. p-diethylaminostyryl) were introduced to an aryl structure of fulgide and photochromic performance was investigated. It was found that the strong electron-donating ability of the substituents caused a significant red shift of the colored form to the near-infrared region (lambda(max); 633 nm), resulting in a high molecular extinction coefficient (epsilon(max); 24300 mol-1 cm-1). Furthermore, rapid reactions of both coloration and discoloration were observed; the quantum yields (phi(EC) and phi(CE)) were 0.65 and 0.052, respectively.