吉林大学陈于蓝团队报道了通过机械致变色和光致变色亚基的协同耦合，从单一发色团获得多色。相关研究成果发表在2023年1月15日出版的《德国应用化学》。

研究人员报道了一种多功能的机械载体，其显示出可生动检测、可光调节的多色机械色变。这种光学特征依赖于机械变色双罗丹明（Rh）和光致变色双噻吩乙烯（BTE）的协同耦合。含有这种双机械载体的聚（丙烯酸甲酯）可以在超声作用下被机械活化。两种不同颜色和荧光的Rh开环产物的相对分布随施加的力的大小而改变。正交使用BTE核的光致变色反应可以增强聚合物的机械变色性并控制聚合物的机械荧光。由于BTE连接提供的共轭增加，力和光诱导的光信号都显示出高对比度。

DFT模拟和实验结果表明，该发色团中的三个亚基（两个Rh和一个BTE）依次激活，从而产生可切换的三色形式和梯度光学响应。

附：英文原文

Title: Multicolor chromism from a single chromophore through synergistic coupling of mechanochromic and photochromic subunits

Author: Weiye He, Yuan Yuan, Mengjiao Wu, Xinxin Li, Yanbing Shen, Zhiyu Qu, Yulan Chen

Issue&Volume: 2023-01-15

Abstract: We report a versatile mechanophore exhibiting a vividly detectable, light-regulable multicolor mechanochromism. Such optical features rely on the synergistic coupling of mechanochromic bis-rhodamine (Rh) and photochromic bisthienylethene (BTE). Poly(methyl acrylate)s incorporating this bis-mechanophore can be mechanically activated under sonication. The relative distribution of the two distinctly colored and fluorescent Rh ring-opening products is altered with different magnitudes of applied force. Orthogonal use of the photochromic reaction of the BTE core can strengthen the mechanochromism and gate the mechanofluorescence in polymers. Due to increased conjugation offered by the BTE linker, both force- and light-induced optical signals display high contrast. Combined DFT simulated and experimental results reveal that the three subunits (two Rhs and one BTE) in this chromophore are activated sequentially, thus generating switchable three-colored forms and gradient optical responses.

DOI: 10.1002/anie.202218785

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202218785