Photosalient Effect of a Diarylethene with a Perfluorocyclohexene Ring

Abstract

Crystals of a diarylethene with a perfluorocyclohexene ring exhibit a remarkable photosalient effect upon UV light irradiation that is attributed to the structural changes that occur when going from open- to closed-ring isomers in the crystalline state, together with the existence of two conformers with different photoconversions compared with those of a perfluorocyclopentene derivative. Our current results give a design principle for molecular structures so as to achieve the photosalient effect for photochromic crystals.

Photochromic Crystalline Systems Mimicking Bio‐Functions

“…Upon UV irradiation, both conformers undergo a cyclization reaction from 7o to 7c.T he longitudinal axes of the blue-and green-colored conformers shrunkf rom 6.736 and 6.742 ,r espectively,t o6 .132 ,b oth at shrinkager atios of roughly 9.0 %. The horizontal axes of the conformers A (blue) and B( green)o f7o were 13.662 and 13.646 .T hey expanded to 14.456 when the molecules werec onverted to 7c, [41] and the expansion ratios were 5.8and 5.9 %, respectively. These changes were far larger than those of 6o to 6c,a nd thus the crystal lattices were strongly deformed and finally broke to showphotosalient phenomena ( Figure 21 g, h).…”

“…The horizontal axes of the conformers A (blue) and B (green) of 7 o were 13.662 and 13.646 Å. They expanded to 14.456 Å when the molecules were converted to 7 c , and the expansion ratios were 5.8 and 5.9 %, respectively. These changes were far larger than those of 6 o to 6 c , and thus the crystal lattices were strongly deformed and finally broke to show photosalient phenomena (Figure 21 g, h).…”

“…Thus, small plastic beads (1.0‐μm diameter) containing fluorescent dye were packed into the hollow crystal (Figure a) and the crystal was irradiated with UV light (Figure b). As previously reported, the largest surfaces of a single crystal were found to be the (010), (0−10) planes from X‐ray analysis …”

“…As previously reported,t he largest surfaceso fa single crystal were found to be the (010), (0À10) planes from X-ray analysis. [41] As cyclization reactiono f7o proceeded in the hollow crystal, the photoirradiated surfaceo ft he hollow crystal expanded along aa nd ba xes while shrinking along ca xis, and then deformationo ft he hollow structure was induced ( Figure 24 c). Then the beads immediatelys cattered with the breaking of the walls, in the manner of seeds bursting from impatiens (Figure 24 d,e).…”

Turning on Solid‐State Fluorescence with Light

“…This strong fluorescence turn-on is accompanied by vigorous blasting and/or jumping of the crystals in am anner that visually resembles the motility of thermosalient and photosalient solids. [16][17][18][19][20][21][22][23][24][25][26][27][28][29] Herein we report the reasons behind the dramatic enhancement of the emission of 3 and we explore the detailed mechanism of the related reaction.…”