Advanced Functional Materials, Vol.19, No.14, 2224-2229, 2009
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-Bu-t-4)(5)-Me-2 (cyclophenacene, 1), C60Ph5(C6H4-Bu-t-4)(5)Me-2 (fused corannulene, 2), and C60Ph5(C6H4-Bu-t-4)(3)Me-2 (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 Mel. 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 pi-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 pi-conjugated systems of the molecules in the solid state and retard the intermolecular excited-state quenching process.