NOVEL WATER-SOLUBLE BETA-CYCLODEXTRIN-CALIX[4]ARENE COUPLES AS FLUORESCENT SENSOR MOLECULES FOR THE DETECTION OF NEUTRAL ANALYTES

The synthesis and the host-guest chemistry of two novel fluorescent be ta-cyclodextrin-calix[4]arene couples 1 and 2 is described. The compou nds were prepared by coupling a beta-cyclodextrin linked with an amino xylyl spacer with two different calix[4]arene building blocks each bea ring a fluorophore. The fluorophores attached to 1 and 2 are the 2-nap hthylamine and the dansyl moiety, respectively. The unsymmetric calix[ 4]arene functionalization was achieved by monoprotection of the 1,3-di formylcalix[4]arene. The host molecules 1 and 2 were used as fluoresce nt probes for several organic analytes in aqueous solution. 1 shows se nsitivity for a series of neutral organic guest species, such as stero ids, terpenes, and other natural products. In contrast, compound 2 doe s not show sensitivity for organic analytes in aqueous solution. The d ifferent behavior of the two fluorescent probes 1 and 2 is explained b y the different strength of self-inclusion of each fluorphoric group i nto the beta-cyclodextrin cavity.