Photochromism of Mixed Crystals Containing Bisthienyl-, Bisthiazolyl-, and Bisoxazolylethene Derivatives

Abstract

Single crystals composed of two or three different kinds of diarylethenes, having similar geometrical structures but different colors in the closed-ring isomers, 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a), 1,2-bis(5-methyl-2-phenyl- 4-thiazolyl)perfluorocyclopentene (2a), and 1,2-bis(5-methyl-2-phenyl-4-oxazolyl)perfluorocyclopentene (3a) have been prepared in an attempt to form single crystals which exhibit different colors, depending on illumination wavelengths. When 1a and 2a are mixed in ethanol and the content of 2a in the feed is higher than that of 1a, only a needle-shaped crystal is obtained. The crystal shape is similar to that of 2a. On the other hand, high content of 1a in the feed leads to formation of a block-shaped crystal, of which the shape is similar to that of 1a. At a feed ratio of 1:1 for 1a and 2a, two types of crystals such as needle- and block-shapes are obtained from the same batch. Mixed crystals composed of three kinds of derivatives 1a/2a/3a have also been prepared. A crystal composed of the three derivatives in the molar ratio of 32 (1a):53 (2a):15 (3a) was obtained. X-ray analysis proved that 1a and 3a are packed in the crystal lattice of 2a. The mixed crystal 1a/2a/3a changed color from colorless to yellow, red, and blue upon irradiation with light of appropriate wavelengths.

Photochromism of Diarylethene Molecules and Crystals: Memories, Switches, and Actuators

“…Mixed crystals composed of the three diarylethene derivatives in almost equal amounts have been successfully prepared, as shown in Figure 65b. 759,794 The colorless crystal turned purplish black upon irradiation with 370 nm light. Upon irradiation with >620 These crystals exhibit various colors, such as colorless, yellow, red, blue, orange, purple, green, and black, upon irradiation with light of appropriate wavelengths.…”

Photochromic diarylethene molecules and crystals

“…Although clear full-color change was observed upon photoirradiation, the content of the blue component was very low (<0.5 %). In order to prepare three-component crystals which exhibit full color and contain almost equal amounts of the three-color component diarylethenes, we prepared mixed crystals composed of the following three diarylethene derivatives [17,18].…”

Esterifiable/hydrolytic control of photochromism of diarylethenes with 8-hydroxyquinoline derivatives

“…There were many reports on the diarylethene derivatives, for example, phenol [22], oxazole [23], indole [24], pyrrole [25], thiazole [26] and so on. 8-Hydroxyquinoline [27][28][29][30] has early been received attention because of substituents at 2-, 5-or 7-position of 8-hydroxyquinoline and coordinated with acid, base or other compounds on N-and OH-group of 8-hydroxyquinoline.…”