Synthesis, Electrochemical and Photophysical Properties, and Electroluminescent Performance of the Octa- and Deca(aryl)[60]fullerene Derivatives

Three multifunctionalized organo[60]fullerene derivatives, C60Ph5(C6H4‐tBu‐4)5Me2 (cyclophenacene, 1), C60Ph5(C6H4‐tBu‐4)5Me2 (fused corannulene, 2), and C60Ph5(C6H4‐tBu‐4)3Me2 (phenylene‐bridged fused corannulene, 3) are synthesized by the reaction of C60Ph5Me with 4‐tert‐butylphenylcopper reagent in the presence of pyridine, followed by treatment with MeI. Compounds 1–3 undergo reduction in the range from −1.8 to −2.5 V versus Fc/Fc+ and exhibit photoluminescence behavior with fluorescent quantum yields of 18.5%, 2.5%, and 3.2% with fluorescent lifetimes of 67, 1.1, and 27 ns (1–3, respectively). Organic electroluminescent diode devices using 1–3 are fabricated with π‐conjugated polymers and show external electroluminescent efficiencies of 0.04%, 0.07%, and 0.03% emitting yellow, green, and red light, respectively. The device containing all three compounds emits white light. This result indicates that the bulky addends in 1–3 can effectively isolate the π‐conjugated systems of the molecules in the solid state and retard the intermolecular excited‐state quenching process. Light‐emitting deca(aryl)[60]fullerene derivatives possessing hoop‐shaped cyclophenacene and bowl‐shaped corannulene type π‐electron conjugated systems are synthesized through two‐step organocopper‐mediated addition reactions to [60]fullerene and investigated for electrochemistry, photoluminescence, and electroluminescence.