Designing efficient absorbents for multi-gas adsorption and separation is of critical significance for gas purification in chemical engineering. Multi-cage structure enables sufficient interactions with multi-gas through the restriction effects, which is promising to achieve high multi-gas separation performance. In this work, two isomorphic metal-organic frameworks (MOFs) (SNNU-275, M ​= ​Cu, and SNNU-276, M ​= ​Ni) with three types of cages (octahedral M₆L₄, cuboctahedral M₁₂L₈, and M₁₂L₂₄), which are (3,4)-linked three-dimensional microporous structures formed by stacking M₆(TPA)₄ octahedral coordination molecular cages are synthesized by using tri(4-pyridyl) amine (TPA) ligands and Cu/Ni metals. TPA is selected as the central ligand due to the small size and flexible characteristics. The synthesized SNNU-275 exhibits a good combination of high C₂H₂/CO₂ adsorption selectivity (28), while high C₂H₂ uptake capacity (68 ​cm³ ​g⁻¹) is achieved for SNNU-276 with high stability. In addition, SNNU-275 and SNNU-276 exhibited superior uptake capacity for benzene and water vapor. Overall, this work not only provides new triangular tripyridine-based MOFs with multiple cages for efficient gas purification, but also demonstrated that the multicage engineering is a promising strategy for the multicomponent gas separation.

设计用于多气体吸附和分离的高效吸收剂对于化工中的气体净化具有重要意义。多笼结构通过限制作用使多气体充分相互作用，有望实现高多气体分离性能。在这项工作中，两个同构金属有机框架 (MOF)（SNNU-275，M = Cu 和 SNNU-276，M = Ni）具有三种类型的笼（八面体 M 6 L 4 ，_立方八面_体M ₁₂ L ₈和M ₁₂ L _{24 )，它们是由M 6} (TPA) ₄堆叠而成的(3,4)连接的三维微孔结构使用三（4-吡啶基）胺 (TPA) 配体和 Cu/Ni 金属合成八面体配位分子笼。由于体积小和灵活的特性，TPA被选为中心配体。合成的 SNNU-275 表现出高 C ₂ H ₂ /CO ₂吸附选择性 (28) 和高 C ₂ H ₂吸收容量 (68 cm ³  g ⁻¹) 是为 SNNU-276 实现的，具有高稳定性。此外，SNNU-275 和 SNNU-276 表现出优异的苯和水蒸气吸收能力。总的来说，这项工作不仅提供了新的多笼三角三吡啶基 MOFs 用于高效的气体净化，而且证明了多笼工程是多组分气体分离的一种有前途的策略。