Association of caffeine in water and in aqueous solutions of sucrose

Abstract

The association of caffeine in water and in aqueous sucrose solutions at 25 °C has been investigated by solubility, distribution, enthalpy of dilution and NMR chemical shift measurements. All the results are consistent with a model (the isodesmic model) in which the caffeine associates to form dimers, trimers etc and for which, the equilibrium constant, for each step, in any solvent mixture studied, is the same. Values are presented for thermodynamic quantities which represent the solution properties.