Dual excimer emission of p-terphenyl induced by γ-cyclodextrin in aqueous solutions

Steady-state and time-resolved fluorescence spectroscopy of p-terphenyl (p-T) in an aqueous solution of γ-cyclodextrin (γ-CD) has revealed the presence of three emitting species, namely the locally-excited p-terphenyl, a low-energy excimer emitting at λmax=408 nm and a higher-energy excimer at λmax=390 nm. In the presence of β-cyclodextrin (β-CD), only the locally-excited state is observed. The identity and the kinetics of the emitting species are discussed. This Letter reports on the detection of excimer fluorescence for p-terphenyl.