Abstract: The spectrophotometric titrations have been performed in aqueous solutions with different pHvalues at 25.0℃ to give the stability constants (IgK_s) for inclusion complexa-tion of various 4-substituted phenols with α-, β- and γ- cyclodextrins and binuclear copper (II)-α, β-cyclodextrins complexes. The stoichiometry of the supramolecular complexes formed is 1:1 for all the host cyclodextrins and binuclear copper(II)-cyclodextrins complex-es inclusion complexation with various guest 4-substituted phenols.The molecular recogni-tion mechanism for 4-substituted phenols of the cyclodextrins and binuclear Cu(II) complex-es with cyclodextrins is discussed from the viewpoint of the size/shape-fit, multiple recogni-tion,induced-fit relationship between the host cavity and the guest molecules.The results obtained indicate that the binuclear Cu(II) complex with β-cyclodextrin possesses the spe-cial binding ability and molecular selectivity for 4-substituted phenols.

Key words: Cyclodextrin, Binuclear copper (Ⅱ) complex with cyclodextrin, Molecular recognition, 4-Substituted phenol