3,5-Dibromobiphenyl is an organic compound featuring a biphenyl core substituted with two bromine atoms at the 3 and 5 positions. It is a halogenated aromatic building block with a molecular formula of C12H8Br2. This compound serves as a crucial intermediate in the synthesis of advanced organic electronic materials. Its primary application is as a precursor for the construction of π-conjugated systems, such as oligo(phenylene)s and poly(phenylene)s, which are core components in organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), and other optoelectronic devices. The bromine atoms act as reactive handles for cross-coupling reactions (e.g., Suzuki, Stille, or Negishi couplings), enabling the controlled extension of the conjugated backbone. As a versatile synthetic building block, it is also used in the preparation of liquid crystals, pharmaceuticals, and ligands for catalysis. It is a solid at room temperature and requires careful handling due to its potential irritant properties.