Photochromic isomerization of spirobenzopyran in nanoholes of anodic alumina.
A notable change in the photochromic characteristics was observed when the benzene solution of spirobenzopyran was put in nanoholes of anodic alumina. The absorption peak that appeared in the ultraviolet irradiation process shifted to a shorter wavelength, and the decay time of the decoloration process became approximately 200 times longer than that of the original solution. After a preservation period of several days, however, both the absorption wavelength and the decay time recovered to those of the original solution. These experimental results suggest that the photochromic isomerization in the alumina nanoholes is affected by the large surface area of the matrix rather than the limited free volume.
Saito
Mitsunori
M
Department of Electronics and Informatics, Ryukoku University, Japan. msaito@rins.ryukoku.ac.jp
Tsubokura
Yasuhiro
Y