Cluster-based inorganic–organic hybrid materials

Clusters as building blocks have been used for two types of inorganic-organic hybrid materials. The first are hybrid polymers, with polymer-like properties and structures, where the cluster units crosslink the polymer chains. They are prepared by co-polymerization of organic monomers with functional ligands attached to the clusters. The second type is crystalline metal-organic framework structures which are obtained by coordination chemistry approaches, i.e. by coordinating multifunctional organic ligands to cluster units. This tutorial review shows that both types of cluster-based materials are limiting cases with many options for varying both the cluster units as well as the connecting organic entities.