Cucurbit[7]uril as a molecular platform for the association and isolation of monosaccharides

CHED 371

Bethany C. Collins and Steven C. Haefner, shaefner@bridgew.edu. Department of Chemical Sciences, Bridgewater State College, Bridgewater, MA 02325

Cucurbit[7]uril (CB[7]) was synthesized according to a standard literature procedure and separated from all other homologues by selective dissolution and recrystallization.  While CB[7] is insoluble in water, addition of monosaccharides results in a marked increase in solubility.  The interactions between CB[7] and aqueous monosaccharides were studied using various techniques including infrared and NMR spectroscopies.  Preliminary results indicate that glucose solutions preferentially interact with CB[7] relative to other homologues, and we have found that CB[7] and monosaccharides associate to form a hydrogen-bonded complex which can be isolated from solution by the use of a precipitating solvent, namely acetone or acetonitrile.  Interactions between CB[7] and monosaccharides produce a significant upfield shift of the CB[7] protons as evidenced by 1H NMR.  The synthesis, isolation, and characterization of CB[7] and its subsequent interactions with glucose and mannose will be presented.