A hetero-supermolecular-building-block strategy for the assembly of porous (3,12,24)-connected uru metal–organic frameworks

Supermolecular building block (SBB) approaches have been widely used for synthesizing highly connected metal–organic frameworks (MOFs). However, it remains a challenge to synthesize trinodal MOFs via SBB approaches. Here we report the assembly of (3,12,24)-connected uru-MOFs via a hetero-supermolecular-building-block (hetero-SBB) strategy, that is, using different types of highly connected metal–organic polyhedra (MOPs) as building units. This hetero-SBB strategy allows the facile synthesis of previously inaccessible uru-MOFs via 12-connected cuboctahedral and 24-connected rhombicuboctahedral MOPs. The uru-MOF-1, consisting of hierarchical microporous and mesoporous cages, exhibits a Brunauer–Emmett–Teller area of 3,170 m² g⁻¹. This MOF shows a high methane uptake of 339.6 cm³ (standard temperature and pressure) cm⁻³ at 159 K and 10 bar and is a promising candidate for low-temperature methane storage. The hetero-SBB strategy paves a way for the designed synthesis of highly connected MOFs, which are difficult to synthesize via traditional strategies, by taking advantage of the arsenal of synthetic MOPs.