Wu Xue-Ru, Wu Shu-Qi, Liu Zhi-Kun, Chen Ming-Xing, Tao Jun, Sato Osamu, Kou Hui-Zhong
Engineering Research Center of Advanced Rare Earth Materials (Ministry of Education), Department of Chemistry, Tsinghua University, 100084, Beijing, PR China.
Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Nat Commun. 2024 May 10;15(1):3961. doi: 10.1038/s41467-024-48425-8.
Mechanically interlocked molecules (MIMs) including famous catenanes show switchable physical properties and attract continuous research interest due to their potential application in molecular devices. The advantages of using spin crossover (SCO) materials here are enormous, allowing for control through diverse stimuli and highly specific functions, and enabling the transfer of the internal dynamics of MIMs from solution to solid state, leading to macroscopic applications. Herein, we report the efficient self-assembly of catenated metal-organic frameworks (termed catena-MOFs) induced by stacking interactions, through the combination of rationally selected flexible and conjugated naphthalene diimide-based bis-pyridyl ligand (BPND), [M(CN)] (M = Ag or Au) and Fe in a one-step strategy. The obtained bimetallic Hofmann-type SCO-MOFs [Fe(BPND){Ag(CN)}]·3CHCl (1Ag) and [Fe(BPND{Au(CN)}]·2CHCl·2HO (1Au) possess a unique three-dimensional (3D) catena-MOF constructed from the polycatenation of two-dimensional (2D) layers with hxl topology. Both complexes undergo thermal- and light-induced SCO. Significantly, abnormal increases in the maximum emission intensity and dielectric constant can be detected simultaneously with the switching of spin states. This research opens up SCO-actuated bistable MIMs that afford dual functionality of coupled fluorescence emission and dielectricity.
包括著名的索烃在内的机械互锁分子（MIMs）具有可切换的物理性质，因其在分子器件中的潜在应用而持续吸引着研究兴趣。在此使用自旋交叉（SCO）材料的优势巨大，能够通过多种刺激进行控制并实现高度特异性功能，还能使MIMs的内部动力学从溶液转移到固态，从而实现宏观应用。在此，我们报告了通过合理选择的柔性共轭萘二酰亚胺基双吡啶配体（BPND）、[M(CN)]（M = Ag或Au）和Fe以一步法策略相结合，由堆积相互作用诱导的连锁金属有机框架（称为连锁MOFs）的高效自组装。所得到的双金属霍夫曼型SCO-MOFs [Fe(BPND){Ag(CN)}]·3CHCl（1Ag）和[Fe(BPND{Au(CN)}]·2CHCl·2HO（1Au）具有独特的三维（3D）连锁MOF，由具有hxl拓扑结构的二维（2D）层的多连锁构建而成。两种配合物都经历热诱导和光诱导的SCO。值得注意的是，在自旋状态切换的同时可以检测到最大发射强度和介电常数的异常增加。这项研究开辟了由SCO驱动的双稳态MIMs，其具有耦合荧光发射和介电性质的双重功能。
