We report the synthesis of a fluorescent polycyclic aromatic hydrocarbon dye with a "symmetry-broken" core, derived from the related hexa-peri-benzocoronene core with a fluoranthene subunit. The fluorophore is composed of a pure carbon skeleton without heteroatoms and exhibits remarkable photoluminescence properties with a photoluminescence quantum yield of up to 67% in toluene, exceeding that of the parent hexa-peri-benzocoronene by a factor of 30. The single crystal X-ray structure reveals the distorted polycyclic aromatic hydrocarbon structure, which is responsible for the optoelectronic properties, as supported by density functional theory calculations. We show that the new fluorescent dye can be readily used for the fabrication of organic light-emitting diodes without extensive optimization, whereby solubility in a variety of solvents and successful film formation are decisive.
