Metal-organic frameworks (MOFs) are of great interest for a wide variety of applications, including energy storage and carbon capture, and have outstanding chemical tunability. In order to fully exploit the potential of MOFs for real-world applications, however, we must work towards designing syntheses to obtain MOFs with new sorption or catalytic properties, particularly enabled by new or previously inaccessible structures. While to some extent this can be achieved by the use of new geometries and functionalities of organic linker, one of the key components determining the structure of a MOF is the shape and identity of the metal cluster. By increasing our understanding of the inorganic component, we can obtain control over the nuclearity of the cluster, and hence the connectivity of the MOF, which allows us to dramatically change the MOF structure.