Blue and red photoluminescence of bicapped [60]fullerene-γ-cyclodextrin complex in aqueous solutions

For the first time, a blue and red photoluminescence of [60]fullerene in its aqueous sample solution is reported. The water solubility of [60]fullerene is achieved by its water-soluble bicapped complex with γ-cyclodextrin. Upon UV excitation at 320 nm, this complex produces intense blue and weak red photoluminescence at 440 and 710 nm which are assigned to the radiative 2t1g (LUMO+1)→4hu (HOMO) and 5t1u (LUMO)→4hu (HOMO) transitions of [60]fullerene, respectively. Further, the contribution demonstrates that the blue photoluminescence can be used for a selective probing of [60]fullerene in its mixtures with higher fullerenes even at trace level