| 摘要 |
PROBLEM TO BE SOLVED: To obtain a microcrystalline photochromic material being transparent in the visible region, showing a large change in absorbance upon light irradiation and having excellent durability after repeated use by using a diarylethene having a five-membered heterocycle in each aryl moiety. SOLUTION: This material comprises a diarylethene having a five-membered heterocycle, desirably pyrrole, thiophene, furan or selenophene in each aryl moiety and desirably having a molecular structure of formula I [wherein R<1> and R<1> ' are each CH3 ; R<2> and R<2> ' are each H, CH3 or substituted (phenyl); and R<3> and R<3> ' are each H or CH3 ]. It is obtained by for example dissolving a diarylethene in ethanol, pouring the obtained solution into an intensely agitated water to form an aqueous solution of microcrystals, admitting the solution into a precision filter membrane to form an aqueous solution which exhibits no scattering at a wavelength of 400nm or above, mixing this aqueous solution with an aqueous PVA solution and casting the mixture to form a thin polymer film containing the microcrystals in a high concentration. |
