A diarylethene with a perfluorocyclohexene ring formed hollow crystals by sublimation under normal pressure. Upon UV irradiation of the crystals, they showed remarkable photosalient phenomena and scattered into small pieces. The speed of the flying debris released from the crystal by UV irradiation exceeded several meters per second. To clearly show a photosalient effect resembling the scattering behavior of Impatiens on a smaller scale, small fluorescent beads (1-μm diameter) were inserted into the hollow crystal. Consequently, scattering of the beads was observed as UV irradiation caused deformation and bursting of the hollow structure. This phenomenon is unique to hollow crystals, and the ability to effectively induce remarkable photosalient phenomena is similar to the behavior of hollow-structured Impatiens in nature.

Double roughness structure, the origin of the lotus effect of natural lotus leaf, was successfully reproduced on a diarylethene microcrystalline surface. Static superwater-repellency and dynamic water-drop-bouncing were observed on the surface, in the manner of natural lotus leaves. Double roughness structure was essential for water-drop-bouncing. This ability was not observed on a single roughness microcrystalline surface showing the lotus effect of the same diarylethene derivative. The double roughness structure was reversibly controlled by alternating irradiation with UV and visible light.

The photoresponse of diarylethene crystalsi s found to depend on the intensity of UV light, that is, photoinduced bending is switched to photosalient phenomenab y increasing the light intensity.T he change in the size of the crystal unit cell upon UV irradiation is larger for asymmetric diarylethenes with thiazole and thiophene rings than that for the corresponding symmetric diarylethenes. As ar esult, the crystalso fa na symmetric diarylethenes how much more drastic photosalient effects than those of the corresponding symmetric diarylethene crystals upon UV irradiation. It is also found that the crystals of diarylethene, which have not previously been reported to exhibit ap hotosalient effect, show photosalient phenomena upon irradiation with strong UV light. Furthermore, the dependence of photosalientp henomenaont he size and shape of the crystals is reported.

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.

Get selective! Enantioselective allylation of ketimines derived from isatins by using chiral 1,3-bis(imidazolin-2-yl)benzene (Phebim)-Pd(II) complexes afforded products with good enantioselectivity (see scheme). The reaction was applied to a wide variety of ketimines. The obtained product can be converted to homoallylic amines and a spirocyclic amine without the loss of enantiopurity.