The link between supramolecular chemistry and coordination polymer materials

Supramolecular chemistry has been dramatically enriched by emerging class of coordination polymers constructed from metal ions and organic linkers. Nowadays, coordination polymers are of particular importance in the world of crystal engineering due to their potential uses as storage devices as well as nonlinear optical switches, luminescent materials and temperature sensors. Of course, other applications have significantly expanded in the past decade.

One of the most important elements in the design of networks is the coordinate-covalent bond between metal and ligand that's strength and directionality all lead to the development of diverse supramolecular designs. It is interesting to note that the dimensionality of the network can be enhanced by adding specific components that are not covalently bonded but employ intermolecular and intramolecular hydrogen bonds. With a sophisticated combination of organic linkers with specific metal cations, a wide range of new supramolecular structures are possible to obtain. For instance, by far the most exploited metal ions in coordination polymer chemistry are zinc ions. They have a d10 electronic configuration feature a variety of coordination modes and spatial arrangements, ranging from octahedral to tetrahedral geometrical dispositions.

Indeed, metal species are able to form complex compounds with different nuclearities and, when combined with the suitable linkers and ligands, all sorts of designs like 1D, 2D, and 3D structures are possible to obtain. Carboxylate anion, which is commonly used as a ligand in traditional coordination chemistry because of its capacity to make stabile Zn(II) complexes. It is often used in the creation of coordination polymers. However, the capability to predict crystal packing and supramolecular assembly within the solid phase is an ongoing problem.