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Keywords:

  • electroluminescence;
  • fullerenes;
  • organic light-emitting diodes;
  • organocopper reagents;
  • photoluminescence

Abstract

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 13 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 (13, respectively). Organic electroluminescent diode devices using 13 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 13 can effectively isolate the π-conjugated systems of the molecules in the solid state and retard the intermolecular excited-state quenching process.