6533b7d4fe1ef96bd1262bc4

RESEARCH PRODUCT

The Recognition of Viologen Derivatives in Water by N-Alkyl Ammonium Resorcinarene Chlorides

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description

Three water-soluble N-alkyl ammonium resorcinarene chlorides decorated with terminal hydroxyl groups at the lower rims were synthesized and characterized. The receptors were decorated at the upper rim with either terminal hydroxyl, rigid cyclohexyl, or flexible benzyl groups. The binding affinities of these receptors toward three viologen derivatives, two of which possess an acetylmethyl group attached to one of the pyridine nitrogens, in water were investigated via 1H NMR spectroscopy, fluorescence spectroscopy, and isothermal titration calorimetry (ITC). ITC quantification of the binding process gave association constants of up to 103 M-1. Analyses reveal a spontaneous binding process which are all exothermic and are both enthalpy and entropy driven. peerReviewed