Mechanically interlocked structures such as rotaxanes and catenanes provide a novel backbone for constructing functional materials with unique structural characteristics. In this study, the novel photoswitchable [n]rotaxanes 11 and 12 based on dithienylethene unit were efficiently synthesized by the classical template-directed clipping approach. And their structures were well-confirmed by NMR, MS and elemental analysis. Investigation on photochromic properties indicated that dithienylethene-based [n]rotaxanes had good reversibility and excellent fatigue resistance upon irradiation with UV or visible light. And they displayed also excellent fluorescence switchable behavior. Interestingly, It was found that [2]rotaxane 11 had better photoisomerization properties in comparison to its corresponding macrocycle 4, which indicated that the non-covalent components on the [2]rotaxane 11 could influence the photoswitching properties. Furthermore, the mechanically interlocked molecules containing two dithienylethene backbones displayed around a 2-fold increase in the molar absorption coefficient compared with that of the mono dithienylethene derivative, which was consistent with the reported [n]rotaxane 9 and 10.

机械互锁的结构，例如轮烷和链烷，为构建具有独特结构特征的功能材料提供了新颖的骨架。在这项研究中，新颖的基于二噻吩乙烯单元的可光开关的[n]轮烷类化合物11和12是通过经典的模板定向剪切方法有效合成的。并通过核磁共振，质谱和元素分析已很好地确认了它们的结构。对光致变色性质的研究表明，二噻吩基乙烯基[n]轮烷具有良好的可逆性，并在紫外线或可见光照射下具有出色的抗疲劳性。而且它们还显示出出色的荧光可切换行为。有趣的是，发现[2]轮烷11与相应的大环化合物4相比，它具有更好的光异构特性，这表明[2]轮烷11上的非共价成分可能会影响光开关特性。此外，与单二噻吩乙烯衍生物相比，包含两个二噻吩乙烯骨架的机械互锁分子的摩尔吸收系数提高了约2倍，这与报道的[n]轮烷烷9和10一致。