Su Jian, Xu Ning, Murase Ryuichi, Yang Zhi-Mei, D'Alessandro Deanna M, Zuo Jing-Lin, Zhu Jia
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China.
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210023, P. R. China.
Angew Chem Int Ed Engl. 2021 Feb 23;60(9):4789-4795. doi: 10.1002/anie.202013811. Epub 2021 Jan 4.
A series of stable radical 2D metal-organic frameworks has been assembled. (m-TTFTB) (m-Tetrathiafulvalene-tetrabenzoate) trimer building blocks are beneficial for the stability of the radicals due to delocalization of the unpaired electron. Hexanuclear rare-earth-cluster-based 1D chains further enhance the stability of the frameworks. The radical state of the middle TTF in the trimer has been observed by the change of central C-C and C-S bond distances and the configuration of the TTF by single-crystal X-ray diffraction. The radical characteristics are also confirmed by electron paramagnetic resonance, UV/Vis-NIR absorption, and X-ray photoelectron spectroscopy experiments. Stability tests showed that the radicals are stable even in solutions and under acid/base environments (pH 1-12). Owing to efficient light absorption due to intramolecular charge transfer, low thermal conductivity, and outstanding stability, the radical 2D Dy-MOF shows excellent photothermal properties, an increase of 34.7 °C within 240 s under one-sun illumination.
一系列稳定的自由基二维金属有机框架已被组装出来。（间-四硫富瓦烯四苯甲酸酯）（m-Tetrathiafulvalene-tetrabenzoate）三聚体构建单元由于未成对电子的离域作用，有利于自由基的稳定性。基于六核稀土簇的一维链进一步增强了框架的稳定性。通过单晶X射线衍射观察到三聚体中间TTF的自由基状态，表现为中心C-C和C-S键距离的变化以及TTF的构型变化。电子顺磁共振、紫外/可见-近红外吸收和X射线光电子能谱实验也证实了自由基特性。稳定性测试表明，即使在溶液中以及酸/碱环境（pH 1-12）下，自由基也是稳定的。由于分子内电荷转移导致的高效光吸收、低热导率和出色的稳定性，自由基二维Dy-MOF表现出优异的光热性能，在一个太阳光照下240秒内温度升高34.7°C。
