Diphenic acid

Diphenic acid
Names
	Preferred IUPAC name [1,1′-Biphenyl]-2,2′-dicarboxylic acid
	Other names 2,2'-dibenzoic acid
Identifiers
CAS Number	482-05-3;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:23837;
ChEMBL	ChEMBL79411;
ChemSpider	9795;
ECHA InfoCard	100.006.889
EC Number	207-576-4;
Gmelin Reference	536420
PubChem CID	10210;
UNII	QY5X735ZIM;
CompTox Dashboard (EPA)	DTXSID0060064 ;
	InChI InChI=1S/C14H10O4/c15-13(16)11-7-3-1-5-9(11)10-6-2-4-8-12(10)14(17)18/h1-8H,(H,15,16)(H,17,18) Key: GWZCCUDJHOGOSO-UHFFFAOYSA-N;
	SMILES C1=CC=C(C(=C1)C2=CC=CC=C2C(=O)O)C(=O)O;
Properties
Chemical formula	C14H10O4
Molar mass	242.230 g·mol−1
Appearance	white solid
Density	1.2917 g/cm3
Melting point	235.5 °C (455.9 °F; 508.6 K)
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Diphenic acid, also known as Dibenzoic acid, is an organic compound with the formula (C₆H₄CO₂H)₂. It is the most studied of several isomeric dicarboxylic acids of biphenyl. It is a white solid that can be prepared in the laboratory from anthranilic acid via the diazonium salt. It is the product of the microbial action on phenanthrene.

The compound forms a variety of coordination polymers. It also exhibits atropisomerism. It can form an internal anhydride featuring a seven-membered ring fused to the two benzene rings.