Effect of cyclodextrin complexation on excited state proton transfer reactions

Steady state and time-resolved fluorometric investigations of the excited state proton transfer reactions of carbazole and 2-naphthylamine in the presence of β-cyclodextrin are reported in this paper. The results, together with earlier reports, reveal that the prototropic reaction depends not only on the microenvironment of the molecule, which is imposed by cyclodextrin, but also on the nature of the molecule itself. Thus, in comparison with the bare chromophore, the deprotonation rate of the cyclodextrin inclusion complex is enhanced when the guest molecule is carbazole, whereas it is decreased for guests like naphthylamine or naphthols