Cheng Shao-Chi, Wang Chi-Hsien, Lin Yi-Chia, Tsuchido Yoshitaka, Suzaki Yuji, Sei Yoshihisa, Kuo Ting-Shen, Horie Masaki
Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.
Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
ACS Appl Mater Interfaces. 2020 Nov 4;12(44):50002-50010. doi: 10.1021/acsami.0c15171. Epub 2020 Oct 22.
This work describes the design and characterization of photoresponsive dynamic pseudorotaxane crystals composed of azobenzene and ferrocenyl groups in an ammonium cation axle component threaded through dibenzo[24]crown-8 ether rings. Pseudorotaxanes provide flexibility for cis and trans isomerization of azobenzene groups in a crystal state, enabling reversible bending motions under alternating 360 and 445 nm laser irradiation. For such bending motions, strained azobenzene structures were essential; these motifs were obtained by increasing the bulkiness of the substituents on the axle and ring molecules. In addition, the crystals showed photosalient effects, such as jumping motions, under 445 nm laser irradiation. These motions were assisted by the photoabsorption of the ferrocenyl group, which converted 445 nm laser light into heat. The maximum lifting weight accompanied by the photoinduced mechanical motion of a particular crystal was estimated to be 9600 times the crystal weight. These pseudorotaxane crystals exhibit promising features for applications in micro-nanometer-sized miniature mechanical devices.
这项工作描述了由偶氮苯和二茂铁基组成的光响应性动态准轮烷晶体的设计与表征，这些基团位于穿过二苯并[24]冠-8醚环的铵阳离子轴组分中。准轮烷为晶体状态下偶氮苯基团的顺反异构化提供了灵活性，使得在交替的360和445nm激光照射下能够进行可逆的弯曲运动。对于这种弯曲运动，应变偶氮苯结构是必不可少的；这些结构单元是通过增加轴和环分子上取代基的体积而获得的。此外，这些晶体在445nm激光照射下表现出光致跳跃等光突效应。这些运动是由二茂铁基的光吸收辅助的，它将445nm激光转化为热量。特定晶体的光致机械运动所伴随的最大提升重量估计为晶体重量的9600倍。这些准轮烷晶体在微纳米尺寸的微型机械设备应用中展现出了有前景的特性。
