Unique molecular recognition property of bis-pyrene-modified β-cyclodextrin dimer in collaboration with γ-cyclodextrin Original Research Article

β-Cyclodextrin (β-CyD) dimer modified with two pyrene moieties, 6-(2-pyrenebutylate-aminoethyl)pyrenebutylate-amino-6-deoxy-bis-β-CyD (β-1) has been prepared to investigate the chemo-sensing ability for organic guests and the host–guest complexation behavior in the presence of γ-CyD. This fluorescent cyclodextrin dimer showed monomer and excimer emissions; the guest-induced emissions were observed as increase or decrease depending on the guest molecules. The sensing parameters, image and image, were used to describe the sensing ability of β-1, where image, Im, Iex and image were fluorescence intensities of monomer and excimer emission, respectively, in the presence and absence of the guest and image and image. This host particulary able to distinguish between ursodeoxycholic acid and chenodeoxycholic acid, which are related as diasteromer. It is observed that supramolecular association between the β-1 and γ-CyD was formed in the presence of 1-adamantanol and bisphenol A as a guest. In this work, we succeeded to make a new type of supramolecular assembly system based on hetero association between a guest, β-1 and γ-CyD.