Diphenic acid is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

with the formula (C₆H₄CO₂H)₂. It is the most studied of several isomeric dicarboxylic acids of

biphenyl Biphenyl (also known as diphenyl, phenylbenzene, 1,1′-biphenyl, lemonene or BP) is an organic compound that forms colorless crystals. Particularly in older literature, compounds containing the functional group consisting of biphenyl less one ...

. It is a white solid that can be prepared in the laboratory from

anthranilic acid Anthranilic acid is an aromatic acid with the formula C6H4(NH2)(CO2H) and has a sweetish taste. The molecule consists of a benzene ring, ''ortho''-substituted with a carboxylic acid and an amine. As a result of containing both acidic and basic f ...

via the

diazonium salt Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. General properti ...

. It is the product of the microbial action on

phenanthrene Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics and pesticides, e ...

. The compound forms a variety of

coordination polymer A coordination polymer is an inorganic or organometallic polymer structure containing metal cation centers linked by ligands. More formally a coordination polymer is a coordination compound with repeating coordination entities extending in 1, 2, o ...

s.{{cite journal, doi=10.1021/cg801085d, title=A Series of Lead(II) Complexes with π−π Stackings: Structural Diversities by Varying the Ligands, journal=Crystal Growth & Design, volume=9, issue=4, pages=1894–1911, year=2009, last1=Yang, first1=Jin, last2=Ma, first2=Jian-Fang, last3=Liu, first3=Ying-Ying, last4=Ma, first4=Ji-Cheng, last5=Batten, first5=Stuart R. It also exhibits

atropisomerism Atropisomers are stereoisomers arising because of hindered rotation about a single bond, where energy differences due to steric strain or other contributors create a barrier to rotation that is high enough to allow for isolation of individual co ...

References

Biphenyls Benzoic acids Carboxylic acids