2,7-Dichlorofluorene is an organic compound featuring a fluorene core substituted with chlorine atoms at the 2 and 7 positions. This specific substitution pattern is crucial for its electronic properties, making it a versatile and important building block in materials science. Its primary and most significant application is as a key monomer or precursor in the synthesis of conjugated polymers and small molecules for organic electronic devices. The chlorine atoms serve as excellent leaving groups in cross-coupling reactions (e.g., Suzuki, Stille), enabling the efficient construction of extended π-conjugated systems. It is extensively used to create polyfluorenes and their copolymers, which are fundamental materials for organic light-emitting diodes (OLEDs), organic photovoltaics (OPVs), and organic field-effect transistors (OFETs). The fluorene unit contributes to high charge carrier mobility and good thermal stability. Beyond its role in advanced materials, 2,7-dichlorofluorene is also a valuable synthetic intermediate in organic chemistry for constructing complex polycyclic aromatic frameworks. It is handled as a solid and requires standard precautions for handling halogenated aromatic compounds.