G-Cyclodextrins Bearing a Pyrenylamide Moiety. The Effect of Photoexcited-state Acid-Base Equilibrium of Appended Chromophone on Their Guest Binding

Abstract

γ-Cyclodextrins bearing a pyrenylamide moiety at primary or secondary hydroxyl side (1 and 2, respectively) showed red-shifted fluorescence as well as normal fluorescence in a solution of pH below 3. This red-shifted fluorescence was emitted from the pyrenylamide moiety protonated in the excited state. Guest binding ability of 2 was markedly affected by the protonation, while that of 1 was harldy affected