Yang Huajun, Peng Fang, Schier Danielle E, Markotic Stipe A, Zhao Xiang, Hong Anh N, Wang Yanxiang, Feng Pingyun, Bu Xianhui
Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, CA, 90840, USA.
Department of Chemistry, University of California, Riverside, Riverside, CA, 92521, USA.
Angew Chem Int Ed Engl. 2021 May 10;60(20):11148-11152. doi: 10.1002/anie.202017042. Epub 2021 Apr 8.
For rare-earth separation, selective crystallization into metal-organic frameworks (MOFs) offers new opportunities. Especially important is the development of MOF platforms with high selectivity toward target ions. Here we report a MOF platform (CPM-66) with low-coordination-number environment for rare-earth ions. This platform is highly responsive to the size variation of rare-earth ions and shows exceptional ion-size selectivity during crystallization. CPM-66 family are based on M O trimers (M=6-coordinated Sc, In, Er-Lu) that are rare for lanthanides. We show that the size matching between urea-type solvents and metal ions is crucial for their successful synthesis. We further show that CPM-66 enables a dramatic multi-fold increase in separation efficiency over CPM-29 with 7-coordinated ions. This work provides some insights into methods to prepare low-coordinate MOFs from large ions and such MOFs could serve as high-efficiency platforms for lanthanide separation, as well as other applications.
对于稀土分离而言，选择性结晶到金属有机框架（MOF）中提供了新的机遇。特别重要的是开发对目标离子具有高选择性的MOF平台。在此，我们报道了一种具有低配位数环境的用于稀土离子的MOF平台（CPM-66）。该平台对稀土离子的尺寸变化高度敏感，并且在结晶过程中表现出卓越的离子尺寸选择性。CPM-66家族基于M O三聚体（M = 六配位的Sc、In、Er-Lu），这对于镧系元素来说较为罕见。我们表明尿素型溶剂与金属离子之间的尺寸匹配对于它们的成功合成至关重要。我们进一步表明，与具有七配位离子的CPM-29相比，CPM-66能使分离效率显著提高数倍。这项工作为从大离子制备低配位MOF的方法提供了一些见解，并且此类MOF可作为镧系元素分离以及其他应用的高效平台。
