強発光と高性能単イオン磁性を示す多機能性シアノ架橋型錯体の研究

今年，我本着寻找基于稀土配合物的新型功能发光单分子磁体(SMM)的研究目标，重点研究了由Tb(III)和六氰基钴(III)构建的氰基桥联d-f双金属配位框架的磁性和发光。单晶结构研究表明，该骨架可以承受由室温水化和热脱水可逆诱导的水合相{[Tb(H2O)2][Co(CN)6]2H2O}0.7H2O和脱水相Tb[Co(CN)6]之间的拓扑定向转变。因此，功能中心Tb(III)离子在磁性和发光性质上都表现出可切换的特性。脱水后，Tb络合物转变为高度对称的三棱柱几何结构，这导致了非常大的磁各向异性，其Orbach势垒超过约450 cm^(-1)。如此高的价值可以与历史上最好的Tb(III)-酞菁SMM系统相媲美，我们在这项工作中自豪地推出了一种全新的高性能Tb(III)-SMM。此外，由于配位场的变化，Tb中心的发光强度和光谱模式也发生了变化，导致了光学温度特性的改变。值得注意的是，SMM行为的工作温度范围和脱水相的光学测温在6K到45K之间有很大的重叠，这种温度重叠是迄今为止最宽的，这为SMM功能中心的实时温度监测提供了很大的可能性。

This year, following the research objective of searching for novel functional luminescent single-molecule magnets (SMMs) based on lanthanide complexes, I have focused on the magnetic and luminescent studies on a cyanido-bridged d-f bimetallic coordination framework built of Tb(III) and hexacyanocobaltate(III). Single crystal structure study unveiled that this framework can bear a topotactic transformation between an as-synthesized hydrated phase, {[Tb(H2O)2][Co(CN)6] 2H2O}0.7H2O, and its dehydrated phase, Tb[Co(CN)6], reversibly induced by room temperature hydration and thermal dehydration. As a consequence, the functional center, Tb(III) ion, exhibits a switchable characteristics on both magnetic and luminescent properties. Upon dehydration, the Tb complex converts into a highly symmetric trigonal prism geometry, which leads to a very large magnetic anisotropy with Orbach energy barrier over ca. 450 cm^(-1). Such high value is comparable to the very historical yet best Tb(III)- phthalocyaninato SMM system, and we proudly introduce a totally new class of high-performance Tb(III)-SMM in this work. In addition, the Tb-centered luminescence intensity and spectral pattern change due to the variation of ligand field, resulting in a modified optical thermometric characteristic. Notably, the working temperature ranges of SMM behavior and the optical thermometry for the dehydrated phase overlap largely between 6 K to 45 K. Such temperature overlap is to-date the widest, and it opened great possibility of real-time temperature monitoring for the functioning center of a SMM.