In supramolecular chemistry, an aromatic interaction (or π-π interaction) is a noncovalent interaction between organic compounds containing aromatic moieties. π-π interactions are caused by intermolecular overlapping of p-orbitals in π-conjugated systems, so they become stronger as the number of π-electrons of increases. Other noncovalent interactions include hydrogen bonds, van der Waals forces, charge-transfer interactions, and dipole-dipole interactions. Supramolecular chemistry is a relatively new field of chemistry which focuses quite literally on going beyond molecular chemistry. ... The term orbital has several meanings: in physics and chemistry it is used to describe an atomic electron configuration, see also molecular orbital and atomic orbital. ... In chemistry, a hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. ... The title given to this article is incorrect due to technical limitations. ... A charge transfer complex is defined over a pair of a molecular groups, where one is electron donating and the other is electron accepting, where there is a partial transfer of electronic charge from the acceptor to the donor in an excited molecular state(excited state). ... Intermolecular forces are electromagnetic forces which act between molecules or between widely separated regions of a macromolecule. ...

π-π interactions act strongly on flat polycyclic aromatic hydrocarbons such as anthracene, triphenylene, and coronene because of the many delocalized π-electrons. This interaction, which is a bit stronger than other noncovalent interactions, plays an important role in various parts of supramolecular chemistry. For example, π-π interactions have a big influence on molecule-based crystal structures of aromatic compounds. An aromatic hydrocarbon (abbreviated as AH), or arene is a hydrocarbon, the molecular structure of which incorporates one or more planar sets of six carbon atoms that are connected by delocalised electrons numbering the same as if they consisted of alternating single and double covalent bonds. ... In chemistry, anthracene is a solid polycyclic aromatic hydrocarbon consisting of three benzene rings derived from coal-tar. ... In chemistry, triphenylene is the name of an organic compound. ... Coronene is an aromatic molecule consisting of 7 benzene rings. ... In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. ... In chemistry, an aromatic molecule is one in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. ...

Uses in Materials

Many discotic liquid crystals can form columnar structures by π-π interactions. In addition, π-π interactions are an important factor in self-assembly techniques in bottom-up nanotechnology. The columnar phase is a class of liquid-crystalline phases in which molecules assemble into cylindrical structures to act as mesogens. ... Self-assembly is the fundamental principle which generates structural organization on all scales from molecules to galaxies. ... A mite next to a gear set produced using MEMS, the precursor to nanotechnology. ...

See also

• Aromaticity
• Stacking (chemistry)