Multicolor Photochromism of Fulgide Mixed Crystals with Enhanced Fatigue Resistance

• Published in: Crystal growth & design Vol. 17; no. 6; pp. 3040 - 3047
• Main Authors: Weerasekara, Roshan K., Uekusa, Hidehiro, Hettiarachchi, Champika V.
• Format: Journal Article
• Language: English
• Published: American Chemical Society 07.06.2017
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.6b01708

Two photochromic mixed fulgide single crystal systems showing multicolor photochromism and enhanced fatigue resistance were prepared with isostructural molecular pairs containing methyl-chloro and methyl-bromo groups. Parent crystals p-methylacetophenylisopropylidenesuccinic anhydride (1E), p-chloroacetophenylisopropylidenesuccinic anhydride (2E), and p-bromoacetophenylisopropylidenesuccinic anhydride (3E) showed light magenta, brownish orange, and orange colors, respectively, upon irradiation at 365 nm. Each two component mixed crystal MIX-1E and MIX-2E composed of 1E/2E and 1E/3E in a 0.39:0.61 and 0.88:0.12 ratio, showed four different colors upon irradiation with UV light and visible light of appropriate wavelengths. Further, it was found that colors of mixed crystals can be fine-tuned to impart different shades of colors over a range of four distinct colors shown by each, upon changing the length of the time irradiated at selected wavelengths. Such multicolored photochromic systems can be used to develop optoelectronic devices upon further improvements.