Itoh Takahiro, Kondo Mio, Sakamoto Hirotoshi, Wakabayashi Kaori, Kanaike Mari, Itami Kenichiro, Masaoka Shigeyuki
Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan.
Dalton Trans. 2015 Sep 14;44(34):15334-42. doi: 10.1039/c5dt01620g.
The incorporation of active sites into metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) is an attractive way to functionalise these materials. However, the methodology to organise substitution-inert metal-based secondary building units (SBUs) with active sites into MOFs or PCPs via coordination driven self-assembly is severely limited. In this study, we successfully assembled substitution-inert paddle-wheel Rh(II) dimers to afford three novel porous frameworks, Rh2(ppeb)4(THF)2 (1-THF), Rh2(ppeb)4(3-pentanone)2 (1-PN) and Rh2(ppeb)4(1-adamantylamine)2 (1-AD) (ppeb = 4-[(perfluorophenyl)ethynyl]benzoate), by using non-covalent interactions. Multipoint arene-perfluoroarene (Ar-Ar(F)) interactions, which allow the unidirectional face-to-face interaction mode of aromatic rings, were used to assemble the substitution-inert paddle-wheel Rh(II) dimers. The obtained frameworks were structurally characterisation by single crystal X-ray diffraction, and it is found that all structures exhibited a one-dimensional channel with active axial sites exposed to the pores. The porous properties of the obtained frameworks were also investigated by thermogravimetric analysis, gas adsorption and powder X-ray diffraction measurements. Moreover, the ligand substitution reaction at the active axial sites was examined at the crystalline state and the flexible structural transformation with the change of channel shapes and sizes was observed.
将活性位点引入金属有机框架（MOF）或多孔配位聚合物（PCP）是使这些材料功能化的一种有吸引力的方法。然而，通过配位驱动自组装将具有活性位点的取代惰性金属基二级结构单元（SBU）组装到MOF或PCP中的方法受到严重限制。在本研究中，我们通过非共价相互作用成功组装了取代惰性的桨轮式Rh（II）二聚体，得到了三种新型多孔框架，即Rh2(ppeb)4(THF)2（1-THF）、Rh2(ppeb)4(3-戊酮)2（1-PN）和Rh2(ppeb)4(1-金刚烷胺)2（1-AD）（ppeb = 4-[(全氟苯基)乙炔基]苯甲酸酯）。利用多点芳烃-全氟芳烃（Ar-Ar(F)）相互作用，这种相互作用允许芳香环的单向面对面相互作用模式，来组装取代惰性的桨轮式Rh（II）二聚体。通过单晶X射线衍射对所得框架进行结构表征，发现所有结构均呈现出一维通道，活性轴向位点暴露于孔中。还通过热重分析、气体吸附和粉末X射线衍射测量研究了所得框架的多孔性质。此外，在晶体状态下研究了活性轴向位点的配体取代反应，并观察到随着通道形状和尺寸的变化而发生的柔性结构转变。
