UV-vis Spectral Analysis of Inclusion Complexes between β -Cyclodextrin and Aromatic/Aliphatic Guest Molecules

beta-Cyclodextrin (beta-CD) forms a series of supramolecular complexes with aromatic or aliphatic guest molecules such as benzaldehyde, butyl acrylate, etc. Remarkable blue shifts (lambda max) of the UV-vis absorption peaks of the guest molecules are observed after the formation of inclusion complexes. The congestion lines appearing in the guest molecules are reduced in a remarkable extent accordingly. The mechanisms of the blue shifts are investigated herein.