Photoresponsive rolling and bending of thin crystals of chiral diarylethenes

Abstract

Dithienylhexafluorocyclopentene with (R)- or (S)-N-phenylethylamide substituents formed rod-like and 0.2-1.0 microm-thick platelike crystals by sublimation; upon UV irradiation, the crystals bent concavely to the incident light and finally rolled crystals were obtained; the bent crystals were reconverted to flat crystals by visible light irradiation.

Light Switching of Molecules on Surfaces

“…This is because the geometric changes required to change from one state to the other are minimal. Indeed photochemistry is preserved even in crystalline states (66)(67)(68). Initial attempts to study the photoswitching of diarylethenes selfassembled on a surface of gold nanoparticles showed that when the switching unit is isolated from the surface by a linker based on a pentamethylene alkyl chain, the photochromism of the compound is retained (69), with both ring closure and ring opening on gold nanoparticles proceeding in a manner similar to that observed in solution.…”

Quantitative Evaluation of Photoinduced Bending Speed of Diarylethene Crystals

“…The photomechanical crystals have attracted much attention because they can work without any direct contact or electrical wires [9]. Various types of photomechanical behaviors such as contraction [8,10], expansion [11], OPEN ACCESS bending [8,[11][12][13][14][15][16][17], separation [18], twisting [19], and rolling [12] have been reported so far. Although photochromic compounds such as diarylethenes [8,19], furylfulgide [20], azobenzene [21,22], anthracene carboxylates [23][24][25][26][27][28], salicylideneaniline [29], 4-chlorocinnamic acid [30], 1,2-bis(4-pyridyl)ethylene salt [31], benzylidenedimethylimidazolinone [32], and others [33] exhibit photochemical reactions in the crystalline phase, their photomechanical motions in the crystal are almost bending.…”

Photoinduced Twisting of a Photochromic Diarylethene Crystal

“…Some diarylethene crystals thus far have been reported to cause the photoinduced reversible bending. [4][5][6][7][8] In the present case, the contraction is considered to occur in the diagonal direction. When irradiated with UV light, the photoisomerization of the diarylethene molecules from the open-ring isomer 1 a to the closed-ring isomer 1 b occurs in the crystalline phase.…”

“…Single microcrystals of diarylethenes have been found to exhibit rapid and reversible macroscopic changes in shape and size upon irradiation with UV and visible light. [4][5][6][7][8] Recently, 9-anthracenecarboxylic acid (9AC) crystals have been shown to twist upon UV light irradiation. [11] 9AC can undergo a reversible [4+4] photocyclodimerization in the crystalline phase.…”

“…[1][2][3] In particular, recent reports have described the development of photomechanical devices with photoresponsive organic crystals, such as diarylethene, anthracene, azobenzene, and furylfulgide. [4][5][6][7][8][9][10][11][12][13] Diarylethenes undergo thermally irreversible and fatigueresistant photochromic reactions, even in the single-crystalline phase. [14] The shape of diarylethene crystals can be modulated solely by photoirradiation.…”