DETECTION OF ORGANIC-COMPOUNDS BY GUEST-RESPONSIVE MONOMER AND EXCIMER FLUORESCENCE OF 6(A),6(B)-BIS(2-NAPHTHYLSULFONYL)-BETA-CYCLODEXTRINS, 6(A),6(C)-BIS(2-NAPHTHYLSULFONYL)-BETA-CYCLODEXTRINS, AND 6(A),6(D)-BIS(2-NAPHTHYLSULFONYL)-BETA-CYCLODEXTRINS

The naphthalene monomer and excimer emissions of 6A,6B-, 6A,6C-, and 6A 6D-bis(2-naphthylsulfonyl)-beta-cyclodextrins (beta-1, beta-2, and beta-3) were used to detect a variety of organic compounds in a 10% ethylene glycol aqueous solution. Beta-1, beta-2, and beta-3 exhibit almost pure monomer fluorescence but exhibit remarkable excimer emission upon addition of guest species, particularly in the cases of beta-2 and beta-3. The intensity of the monomer fluorescence is mostly depressed by the presence of guest species, the absolute variation in the emission intensity being roughly in parallel with that of the excimer emission except for steroids. The orders of the sensitivities are cyclohexanol < cyclododecanol < I-borneol < 1-adamantanecarboxylic acid when measured at the guest concentration of 0.2 mM, and nerol congruent-to geraniol < I-menthol when measured at the guest concentration of 2 mM. Steroid compounds were detected by the monomer emission variation but not by the excimer one, and the order of the sensitivities as measured at the guest concentration of 0.2 mM was cholic acid < deoxycholic acid < chenodeoxycholic acid congruent-to ursodeoxycholic acid. All these results demonstrate that the bichromophoric beta-cyclodextrin derivatives can be used as effective sensors.