Recent advances on supramolecular isomerism in metal organic frameworks

Metal-organic frameworks (MOFs) or coordination polymers (CPs), a class of compounds constructed often by self-assembly of inorganic metal ions and organic ligands, have attracted growing interest on account of their diverse structures, permanent porosity and tunable properties, with a prospect for various applications. In some cases, the self-assembly of the building blocks produces different MOFs with the same molecular composition, i.e., supramolecular isomers. The design of supramolecular isomers in the area of MOFs is challenging and this highlight gathers recently published articles concerning the different types of supramolecular isomers, i.e., structural, conformational, catenane and optical, in this area. The syntheses and structures of the isomers and their comparison are presented, as well as the role of various parameters, such as temperature, solvent, concentration, crystallization method, additive and template, in the formation of the different supramolecular isomers, by analyzing selected examples.