Toward Topology Prediction in Zr-Based Microporous Coordination Polymers: The Role of Linker Geometry and Flexibility

A design strategy based on geometric analysis of linker shape and flexibility is developed in the context of achieving predictable topology of tetratopic-linker based Zr microporous coordination polymers (MCPs). Tetratopic linkers are categorized into tetrahedral, planar square, or planar rectangular groups based on symmetry with an emphasis on linker flexibility. A prediction framework solely based on linker shape and cluster connectivity derived from this strategy is applied to all 18 reported tetratopic-linker based Zr MCPs, and their determined topologies fit well into the scheme. Two new Zr MCPs (UMCM-312 and UMCM-313) are produced using designed linkers based on the strategy to test the robustness of prediction. UMCM-312 contains a biphenyl-core based tetratopic linker to target tetrahedral shape, and UMCM-313 takes advantage of a perylene based tetratopic linker to achieve rectangular shape. The experimentally determined topologies confirm predictions. It is thus demonstrated that the uncertainty of targeting topologies in tetratopic-linker based Zr MCPs can be reduced by accounting for linker shape and flexibility.