Mesostructured Imidazolate Frameworks

Metal-organic frameworks (MOFs) are crystalline hybrid framework materials composed of inorganic metal “nodes” bridged by rigid organic linkers, thereby featuring exceptionally high surface areas and porosities. Despite the successful synthesis of a plethora of intricate framework topologies, a major objective in current MOF chemistry is the extension of pore sizes from the micropore (> 2 nm) to the mesopore regime (2 – 50 nm). In contrast, siliceous materials constitute a large class of inorganic materials spanning different pore size regimes with pore topologies on the micro-, mesoand macroscale. Here, microporous zeolites and mesoporous silica represent the most famous of such ordered siliceous materials.[1] While zeolites have already found MOF analogues named zeolitic imidazolate frameworks (ZIFs), featuring zeolite-like framework topologies, materials that combine metal-organic building blocks with supramolecular templates such as those found in mesostructured silica materials are still elusive. Therefore, the combination of mesophase synthesis, which employs surfactants as supramolecular templates, with the solvothermal synthesis of MOFs and especially ZIFs is one promising avenue that may ultimately afford mesostructured materials with hierarchical, i.e. micro and meso, porosity. Here we describe the first representative of a mesostructured zinc coordination polymer with imidazolate linkers, which has been obtained by an inverse microemulsion-based synthesis.[2]