Framework-Isomeric Metal-Organic Frameworks Built from Supermolecular Building Blocks for High Iodine Capture

The supermolecular building block approach is powerful in constructing hierarchically porous metal-organic frameworks (MOFs). However, the structural diversity of these extended frameworks built from the same building blocks has never been explored. Herein, we propose a strategy by synergistically tuning the extending direction of metal-organic polyhedra (MOPs) and the linker conformation to achieve MOFs with framework isomerism. Six novel MOFs (CCNUF-1-6) based on an octahedral MOP and different tritopic pyridine-based linkers were successfully synthesized, among which the structural diversity increased with increasing linker flexibility. The topologies (sql, kgd, and rtl) of these materials are unprecedented in MOP-based MOFs. Moreover, highly porous CCNUF-2-6 showed remarkable iodine uptake capacities in the range of 2.51 to 3.11 g g-1. This study emphasizes the potential of MOPs containing open metal sites as versatile platforms for the development of diversified hierarchically porous MOFs with enhanced functional properties.