m-Terphenyls (also known as meta-terphenyls, meta-diphenylbenzenes, or meta-triphenyls) are organic molecules composed of two phenyl groups bonded to a benzene ring in the one and three positions.

[3] Due to the extensive pi-conjugated system, the molecule it has a range of optical properties and because of its size, it is used to control the sterics in reactions with metals and main group elements.

[5] Meta-terphenyl, and other aromatic compounds, remained of much interest to scientists in throughout the end of the 20th century, with many of the physical properties being measured and compared during this time.

This also led to the first alternate form of meta-terphenyl synthesis, which involved passing gaseous benzene and toluene through a hot glass tube.

Instead of heating benzene, they found that a combination of dihydroresocinol and two equivalents of phenyllithium would create unsymmetrical meta-terphenyl molecules.

In 1975, Karl-Werner Glombitza, Hans-Willi Rauwald, and Gert Eckhardt isolated two meta-terphenyls from the algae Fugus vesiculosus.

Using an excess of Grignard reagent that had a phenyl group attached, meta-terphenyl was able to be made quickly, in one step, with a relatively high yield.

This method continues to remain very popular in terms of the creation of symmetrical meta-terphenyl compounds, but that has not stopped attempts to quicken synthesis, increase yield, and create more sterically bulky m-terphenyls.

As opposed to general routes to produce common meta-terphenyl compounds, the shift has been to improve certain derivatives to accomplish particular goals.

Their large size can help to sterically force a certain reaction to take place, however they are mainly used to stabilize compounds that would be unstable otherwise.

[23] M-terphenyls have also been quite helpful in getting preliminary structures of divalent lithium and sodium, although both molecules had substantial stabilization from the electron-rich meta-terphenyl group.

Due to its composition and shape, meta-terphenyl can be used as the basis for the formation of synthetic proteins that can bind to carbohydrates, lectins.

This is due to the large twisted shape of meta-terphenyl, when not hindered by bulkier substituents used in organometallics and main-group chemistry, which may opt to increase the rotational barrier of the molecule.