Colliard Ian, Nyman May
Department of Chemistry, Oregon State University, Corvallis, OR, 97331, USA.
Angew Chem Int Ed Engl. 2021 Mar 22;60(13):7308-7315. doi: 10.1002/anie.202016522. Epub 2021 Feb 24.
M molecular oxo-clusters (M=Zr, Hf, Ce, Th, U, Np, Pu) are prolific in bottoms-up material design, catalysis, and elucidating reaction pathways in nature and in synthesis. Here we introduce Ce , a wheel-shaped oxo-cluster, [Ce (OH) (O) (SO ) (H O) ] . Ce crystallizes into intricate high pore volume frameworks with divalent transition metals and Ce-monomer linkers. Eight crystal-structures feature four framework types in which the Ce -rings are linked as propellers, in offset-stacks, in a tartan pattern, and as isolated rings. Small-angle X-ray scattering of Ce dissolved in butylamine, with and without added cations (Ce , alkaline earths, Mn ), shows the metals' differentiating roles in ring linking, leading to supramolecular assemblies. The large acidic pores and abundant terminal sulfates provide ion-exchange behavior, demonstrated with U and Nd . Frameworks featuring Ce -monomer linkers demonstrate both oxidation and reduction. This study opens the door to mixed-metal, highly porous framework catalysts, and new clusters for metal-organic framework design.
M分子氧簇（M = 锆、铪、铈、钍、铀、镎、钚）在自下而上的材料设计、催化以及阐明自然和合成中的反应途径方面应用广泛。在此，我们介绍一种轮状氧簇Ce，即[Ce₁₂(OH)₁₂(O)₁₂(SO₄)₆(H₂O)₆]。Ce与二价过渡金属和Ce单体连接体结晶形成复杂的高孔隙率骨架结构。八种晶体结构具有四种骨架类型，其中Ce环以螺旋桨状、错位堆积、格子图案以及孤立环的形式相连。溶解于丁胺中且添加或不添加阳离子（Ce³⁺、碱土金属、Mn²⁺）的Ce的小角X射线散射表明，金属在环连接中具有不同作用，从而导致超分子组装。大的酸性孔隙和丰富的末端硫酸盐具有离子交换行为，用U⁶⁺和Nd³⁺得以证明。具有Ce单体连接体的骨架结构兼具氧化和还原性能。本研究为混合金属、高孔隙率骨架催化剂以及用于金属有机骨架设计的新型簇合物打开了大门。
