The photophysical properties of azafullerenes C59HN and its dimer (C59N)2

The preliminary photophysical properties of azafullerene materials C59HN and dimer (C59N)(2) are investigated and compared with C-60, C-60 derivatives, and C-60 dimer (C-120). It is found that the quantum yields of the azafullerenes are unexpectedly lower than C-60 with a value of 8.8 x 10(-5) for C59HN and 1.5 x 10(-4) for (C59N)(2) in toluene. The possibility of a photoinduced intramolecular charge transfer process to quench fluorescence of the azafullerenes is ruled out by the effects of solvent polarity and pH. The weak fluorescence of azafullerenes is discussed in terms of El-Sayed's rules.