Supramolecular chemistry

Supramolecular chemistry is a branch of chemistry that deals with the association of molecules to higher-level (supra-)structures. It deals with processes of self-assembly and host-guest chemistry and the resulting supramolecular systems. The field has been shaped by findings on aggregates of enzymes and their substrates. Interdisciplinary methods from all areas of chemistry and physics are used to study supramolecules. Donald J. Cram, Jean-Marie Lehn and Charles Pedersen were awarded the Nobel Prize in Chemistry in 1987 for their contributions to this field, and the 2016 Nobel Prize to Jean-Pierre Sauvage, J. Fraser Stoddart and Bernard L. Feringa also concerned an important area of supramolecular chemistry with molecular machines and mechanically interlocked molecules (such as catenanes, rotaxanes).

Cram explained host-guest complexes as follows:

"These complexes consist of two or more molecules or ions whose unique structures are held together by forces other than covalent bonds. [...] These electrostatic forces include hydrogen bonds, ion-pair formation, acid-base interactions, metal-ligand interactions, van der Waals forces, and hydrophobic interactions."

Among the most studied classes of compounds in supramolecular chemistry are the crown ethers, the cryptands and cryptates, together with the associated metalla-topomers, as well as the cyclodextrins and calixarenes. However, inorganic hosts such as zeolites and polyoxovanadates are also possible.

The study of these associates has several goals: It seeks both to provide deeper insights into the nature of enzyme-substrate complexes and to provide access to improved catalysts and analytical methods. Furthermore, supramolecular chemistry strives to synthesize new materials with properties that are as tailored as possible. Molecular machines such as a molecular switch or a synthetic molecular motor could be mentioned in this context. The most important tool of supramolecular chemistry is spontaneous self-assembly (self-grouping) and self-organization.

[18]Crown-6, a crown ether

Metallo-supramolecular chemistry

In the subfield of metallo-supramolecular chemistry, metal ions are used as important structure-forming assemblies. The structures obtained in this way (for example, lattice-like metal complexes) are referred to as metallo-topomers in comparison with purely organic structures of the same topology.

Questions and Answers

Q: What is supramolecular chemistry?

A: Supramolecular chemistry is an area of chemistry that studies the relationship and linking of molecules into bigger systems.

Q: What does supramolecular chemistry focus on?

A: Supramolecular chemistry focuses on the chemical systems made up of a discrete number of assembled molecular subunits or components.

Q: Why is studying supramolecular chemistry important in understanding biological processes?

A: Studying supramolecular chemistry is important in understanding biological processes because many of these processes rely on non-covalent interactions for structure and function.

Q: What are non-covalent interactions?

A: Non-covalent interactions are weak interactions between molecules that do not involve the sharing of electrons.

Q: How are biological systems related to supramolecular research?

A: Biological systems are often the inspiration for supramolecular research.

Q: Give an example of a biological process that rely on non-covalent interactions for structure and function.
A: A good example of a biological process that relies on non-covalent interactions for structure and function is vision.

Q: What is the purpose of the study of supramolecular chemistry?

A: The purpose of the study of supramolecular chemistry is to understand how molecules interact and assemble into larger structures and systems.