1,1':4',1''-Terphenyl-2',5'-dicarboxylic acid is a rigid, conjugated aromatic dicarboxylic acid derivative. Its structure features a central biphenyl unit with two carboxylic acid groups in the *meta* positions relative to each other, connected via a phenyl ring. This extended π-conjugated system and the presence of reactive carboxyl groups are key to its functionality. This compound serves as a crucial organic semiconductor building block and monomer. Its primary application is in the synthesis of high-performance organic light-emitting diodes (OLEDs), particularly as a precursor for electron-transporting materials (ETMs) and host materials in emissive layers. The carboxylic acid groups allow for its incorporation into metal-organic frameworks (MOFs) and coordination polymers with interesting luminescent or charge-transport properties. Furthermore, it is used as a monomer for constructing rigid-rod polymers and polyamides, imparting high thermal stability and specific mechanical or optical characteristics to the resulting materials. The compound's rigid, planar structure promotes efficient π-π stacking, which is beneficial for charge carrier mobility in electronic devices. It is typically a solid powder and requires handling under standard laboratory conditions for air- and moisture-sensitive compounds.