Synthesis of Tetradeca- and Pentadeca(organo)[60]fullerenes Containing Unique Photo- and Electroluminescent π-Conjugated Systems

Abstract

Dianions of deca(phenyl)[60]fullerene–bis(cyclopentadienyl ruthenium) complex, (C60Ph10)(RuCp)2 (1a), and dimethylated deca(phenyl)[60]fullerene, C60Ph10Me2 (1b), reacted with benzyl bromide to produce [C60Ph10(CH2Ph2)2](RuCp)2 (3a and 4a) and tetradeca(organo)[60]fullerenes C60Ph10(CH2Ph2)2Me2 (3b and 4b), respectively (Compounds 3 and 4 refer to C2v and C1 symmetric compounds, respectively.). Nucleophilic addition of benzylmagnesium chloride with the C1 symmetric compounds 4a and 4b yielded [C60Ph10(CH2Ph2)3H](RuCp)2 (5a) and pentadeca(organo)[60]fullerenes C60Ph10(CH2Ph2)3Me2H (5b), respectively. Products were structurally characterized by X-ray crystallographic analysis of diruthenium complexes 3a, 4a, and 5a. These X-ray studies revealed that compounds 3, 4, and 5 have unique π-conjugated systems consisting of doubly bridged triphenylene dimer, triphenylene–benzoacenaphthylene, and triphenylene–biphenyl structures, respectively. Quantum mechanical calculations suggested that these π-conjugated systems are aromatic. Containing no metal atom, methylated derivatives 3b, 4b, and 5b exhibited green, pale yellow, and turquoise blue emissions with quantum yields of 0.066, 0.12, and 0.24, respectively. The application of these materials in organic light-emitting diodes was demonstrated.