Lu Huangjie, Zheng Zhaofa, Li Zi-Jian, Bao Hongliang, Guo Xiaojing, Guo Xiaofeng, Lin Jian, Qian Yuan, Wang Jian-Qiang
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China.
Key Laboratory of Interfacial Physics and Technology, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai 201800, China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):2745-2752. doi: 10.1021/acsami.0c20036. Epub 2021 Jan 6.
Rational design and synthesis of new photochromic sensors have been active research areas of inquiry, particularly on how to predict and tailor their properties and functionalities. Herein, two thulium 2,2':6',2''-terpyridine-4'-carboxylate (TPC)-functionalized metal-organic hybrids, Tm(TPC)(HCOO)(HO) () and Tm(TPC)(HCOO) () with different photochromic response behaviors, have been successfully prepared, allowing for straightforward investigations of the structure-property correlation. Single-crystal X-ray diffraction and electron paramagnetic resonance analyses revealed that the incorporation of a unique dangling decorating TPC unit in offers a shorter and more accessible π-π interaction pathway between the adjacent TPC moieties than that in . Such a structural feature leads to the production of radical species via a photoinduced intermolecular electron-transfer (IeMCT) process upon UV or X-ray irradiation, which ultimately endows with a rather unusual UV and X-ray dual photochromism. A linear relationship between the change of UV-vis absorbance intensity and X-ray dose was established, making a promising dosimeter for X-ray radiation with an extremely high energy threshold (30 kGy). To advance the development for real-world application, we have fabricated polyvinylidene fluoride (PVDF) membranes incorporating for functioning either as a UV imager or as an X-ray radiation indicator. Lastly, exhibits high thermal stability (up to 400 °C) and radioresistance (at least 900 kGy), and also excellent reversibility of photochromic transformation (at least 5 cycles).
新型光致变色传感器的合理设计与合成一直是活跃的研究领域，特别是关于如何预测和定制其性质与功能。在此，成功制备了两种具有不同光致变色响应行为的铥2,2':6',2''-三联吡啶-4'-羧酸酯（TPC）功能化金属有机杂化物，即Tm(TPC)(HCOO)(HO)（ ）和Tm(TPC)(HCOO)（ ），这使得能够直接研究结构-性质相关性。单晶X射线衍射和电子顺磁共振分析表明，在 中引入独特的悬空修饰TPC单元，与 相比，相邻TPC部分之间提供了更短且更容易接近的π-π相互作用途径。这种结构特征导致在紫外或X射线照射下通过光诱导分子间电子转移（IeMCT）过程产生自由基物种，最终赋予 相当不寻常的紫外和X射线双光致变色特性。建立了紫外可见吸收强度变化与X射线剂量之间的线性关系，使 成为一种具有极高能量阈值（30 kGy）的有前途的X射线辐射剂量计。为了推进实际应用的发展，我们制备了包含 的聚偏二氟乙烯（PVDF）膜，其可作为紫外成像器或X射线辐射指示器发挥作用。最后， 表现出高热稳定性（高达400°C）和抗辐射性（至少900 kGy），并且光致变色转变具有优异的可逆性（至少5个循环）。
