Supramolecular Chemistry

Supramolecular chemistry examines the assembly of discrete molecular entities into organised architectures through reversible, non-covalent interactions. Whereas traditional chemistry focuses on making and breaking covalent bonds, supramolecular chemistry exploits hydrogen bonds, metal–ligand coordination, π–π stacking, electrostatic attraction, dispersion forces, halogen and chalcogen bonding, anion-π and cation-π interactions to guide molecules into higher-order structures. Host–guest complexes, in which a cavity-forming host molecule encapsulates a complementary guest, exemplify the precision of molecular recognition. Metal–organic cages, rotaxanes, catenanes and responsive gels demonstrate how weak forces may combine cooperatively to yield stable yet dynamic systems. Such assemblies underpin developments in catalysis, drug delivery, adaptive materials, chemical sensing and energy conversion. By mimicking natural processes—such as enzyme–substrate binding and membrane transport—supramolecular chemistry offers routes to programmable functions under mild conditions, promoting sustainability and enabling technologies from precision medicine to smart textiles.

Research from Nature Portfolio

A model hexa-cata-hexabenzocoronene doped with boron and phosphorus centres has been shown to capture up to three carbon dioxide molecules. Density functional theory reveals that initial CO₂ binding alters the electronic acidity and basicity of neighbouring sites, enhancing subsequent fixation events via a cooperativity effect driven by π-delocalisation. Activation barriers and thermodynamic profiles indicate that sequential and simultaneous capture pathways are both viable, pointing to new strategies for greenhouse-gas sequestration on extended aromatic surfaces.

Contrary to long-held assumptions, methyl groups bound to atoms less electronegative than carbon can act as Lewis bases in diverse non-covalent interactions. Crystallographic surveys identify thousands of structures where methyl C–H bonds donate electron density into electrophilic sites—ranging from p-block centres to metal ions—via highly directional interactions. Computational analyses confirm significant charge transfer from σ(C–H) orbitals to acceptor orbitals, demonstrating that simple alkyl substituents may engage in purposeful molecular recognition.

Supramolecular Chemistry publication trend

The graph below shows the total number of articles in supramolecular chemistry across all publications each year (not limited to Nature Index journals).

Technical terms

Supramolecular chemistry: The discipline concerned with the organisation of molecules into larger structures via reversible non-covalent interactions.

Non-covalent interaction: A reversible force (electrostatic, dispersion, coordination, etc.) that binds molecular components without forming or breaking covalent bonds.

Host–guest interaction: A specific non-covalent binding event in which a host molecule’s cavity selectively encapsulates a complementary guest.

σ-hole: A region of positive electrostatic potential located along the extension of a covalent bond, enabling directional halogen or chalcogen bonding.

π-hole: An area of positive potential located above or below a molecular plane, facilitating interactions with electron-rich donors.

References

1. Reactivity of a model of B3P3-doped nanographene with up to three CO2 molecules. Scientific Reports (2023).
2. Methyl groups as widespread Lewis bases in noncovalent interactions. Nature Communications (2021).
3. DFT-D4 Insight into the Inclusion of Amphetamine and Methamphetamine in Cucurbit[7]uril: Energetic, Structural and Biosensing Properties. Molecules (2021).
4. Computational Insight into the Nature and Strength of the π-Hole Type Chalcogen∙∙∙Chalcogen Interactions in the XO2∙∙∙CH3YCH3 Complexes (X = S, Se, Te; Y = O, S, Se, Te). International Journal of Molecular Sciences (2023).