Diarylethene microcrystals make directional jumps upon ultraviolet irradiation

Abstract

Microcrystals of a diarylethene {1,2-bis[5'-methyl-2'-(2"-pyridyl)thiazolyl]perfluorocyclo-pentene} undergo jumps upon photoirradiation. These photochromic crystals present molecular structural changes upon irradiation with ultraviolet light because of reversible photocyclization reactions. When the energy absorbed by crystals reaches about 10 microJ, the uniaxial stress induced in the crystal lattice relaxes through directional jumps. If one prevents crystals from jumping, then parallel, equidistant cracks appear on crystal surfaces. These photomechanical effects could result from a Grinfeld surface instability.

Template assisted synthesis of silica-coated molecular crystal nanorods: From hydrophobic to hydrophilic nanorods

“…For now, we speculate that the slowing of the CS nanorod response could be due to the constricting effect of the silica shell. The ability of the rod to undergo a photoinduced crystal-to-crystal transition and remain intact probably relies at least partially on the high surface-to-volume ratio of the nanorods, which alleviates the crystal strain associated with such a transformation [14,[37][38][39][40]. Any shell structure would be likely to inhibit the surface reconstruction necessary for the crystal transformation, and thus delay the geometry change that results from that transformation.…”

Photosalient Effect of a Diarylethene with a Perfluorocyclohexene Ring

“…Irie et al. reported the photoinduced crystal jump of diarylethene microcrystals upon UV irradiation . Many of these diarylethenes that have been synthesized previously have included a five‐membered perfluorocyclopentene ring .…”

Effect of Crystal Packing on the Thermosalient Effect of the Pincer‐Type Diester Naphthalene‐2,3‐diyl‐bis(4‐fluorobenzoate): A New Class II Thermosalient Solid

“…The meltw as cooled, and the solid material also movedw hile solidifying. [2][3][4][5][6][7][8][9][10][11] In contrastwith form I, crystals of form III did not show motion, as determined by HSM, and thus, this polymorph was determined not to be thermosalienta bove room temperature. Af ew crystals that did not jump melted at ah igher temperature ( Figure 1B).…”