Prefabricated Cluster Strategy for the Facile Synthesis of Fluoro-Bridged UiO-66 Analogues

Metal cluster-based metal-organic frameworks (MOFs) offer many classical MOF materials because of their better directionality and selectivity of coordination geometry. However, unlike the numerous substitutable organic ligands and metal ions in MOFs, precisely controlling the inorganic bridging species in the metal cluster remains a significant challenge. Here, we use a prefabricated fluoride-bridged lanthanide cluster as a precursor to unambiguously introduce fluoride bridges into a well-known UiO-66-type MOF with an fcu topology. This blueprint provides eight isoreticular coordination networks with bridging F^- through organic ligand alterations of different lengths and functional groups. The characterization of the content and position of bridging F^- proves the complete substitution of O-bridge with F-bridge. More importantly, the rapid and moderate reaction process allows for the synthesis of ten-gram scale at room temperature within 5 s. Compared with prototypical UiO-66, the bridging F^- in the representative structure can promote C₂H₂ adsorption and conduct efficient C₂H₂/CO₂ separation.