Lei Xiao-Wu, Yang Huajun, Wang Yanxiang, Wang Yong, Chen Xitong, Xiao Yuchen, Bu Xianhui, Feng Pingyun
Department of Chemistry and Chemical Engineering, Jining University, Qufu, Shandong, 273155, P. R. China.
Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA.
Small. 2021 Jun;17(22):e2003167. doi: 10.1002/smll.202003167. Epub 2020 Aug 25.
Metal trimers M (O/OH) are among the most important structural building blocks. From these trimers, a great success has been achieved in the design of 6- or 9-connected framework materials with various topological features and outstanding gas-sorption properties. In comparison, 8-connected trimer-based metal-organic frameworks (MOFs) are rare. Given multiple competitive pathways for the formation of 6- or 9-connected frameworks, it remains challenging to identify synthetic or structural parameters that can be used to direct the self-assembly process toward trimer-based 8-connected materials. Here, a viable strategy called angle bending modulation is revealed for creating a prototypical MOF type based on 8-connected M (OH)(OOCR) (Py-R) trimers (M = Zn, Co, Fe). As a proof of concept, six members in this family are synthesized using three types of ligands (CPM-80, -81, and -82). These materials do not possess open-metal sites and show excellent uptake capacity for various hydrocarbon gas molecules and inverse C H /C H selectivity. CPM-81-Co, made from 2,5-furandicarboxylate and isonicotinate, features selectivity of 1.80 with high uptake capacity for ethane (123 cm g ) and ethylene (113 cm g ) at 298 K and 1 bar.
金属三聚体M(O/OH)是最重要的结构构建单元之一。基于这些三聚体，在设计具有各种拓扑特征和出色气体吸附性能的6或9连接框架材料方面取得了巨大成功。相比之下，基于8连接三聚体的金属有机框架(MOF)却很少见。鉴于形成6或9连接框架存在多种竞争途径，确定可用于将自组装过程导向基于三聚体的8连接材料的合成或结构参数仍然具有挑战性。在此，揭示了一种可行的策略，即角度弯曲调制，用于创建基于8连接M(OH)(OOCR)(Py-R)三聚体(M = Zn、Co、Fe)的原型MOF类型。作为概念验证，使用三种类型的配体(CPM-80、-81和-82)合成了该家族中的六个成员。这些材料不具有开放金属位点，并且对各种烃类气体分子表现出优异的吸附能力和反式C₂H₆/C₂H₄选择性。由2,5-呋喃二甲酸酯和异烟酸酯制成的CPM-81-Co在298 K和1 bar下对乙烷(123 cm³ g⁻¹)和乙烯(113 cm³ g⁻¹)具有高吸附能力，选择性为1.80。
