Exciplex Formation between Perylene and N,N-Dimethylaniline in a Ternary Inclusion Compound with γ-Cyclodextrin in H2O–Ethanol (7 : 3) Mixture

Inclusion compounds in the system of γ-cyclodextrin (γ-CD)-N,N-dimethylaniline (DMA)-perylene (Pe) have been studied in an H2O–ethanol (7 : 3) mixture by means of absorption and fluorescence spectral measurements. A ternary 1 : 1 : 1 inclusion compound of γ-CD–ethanol–Pe is formed by the addition of γ-CD to an H2O–ethanol solution of Pe. In the presence of γ-CD, a further addition of DMA results in the formation of a γ-CD–DMA–Pe inclusion compound followed by association with a 1 : 1 γ-CD–DMA inclusion compound to form a ternary 2 : 2 : 1 inclusion compound of γ-CD–DMA–Pe. The exciplex fluorescence of Pe–DMA within the γ-CD cavity has been observed from the ternary inclusion compound. Equilibrium constants for the formation of these inclusion compounds have been evaluated.