Effect of surfactant-perturbed nanocaging on the ground and excited state proton transfer reaction.

ABSTRACT

The effect of mixed cyclodextrin-surfactant systems on the ground and excited state proton transfer reactions of 4-methyl-2,6-diformylphenol (MFOH) in aqueous solution has been investigated by steady state and time-resolved fluorescence spectroscopy. It has been found that micellar media perturbs the solvation of MFOH and facilitates nanocaging. In the presence of micelle, MFOH preferentially resides in the interfacial region. Depending on the local pH due to compartmentalization of reaction media, normal or anionic form of MFOH dominates. Encapsulation of the probe within the cyclodextrin nanocavity enhances the shorter lifetime component of MFOH unexpectedly, which has been explained on the basis of reduced solvation and reduced dipolar effect due to confinement.