Proton Chemical Shifts and Thermodynamics of the Formation of Hydrogen-Bonded Dimers and Mixed 1:l Associates in the Ternary System Acetic Acid/Met hanol/Tetra hydrofuran- d8

The chemical shifts of the carboxylic proton of acetic acid and of the hydroxylic proton of methanol dissolved together and separately in tetrahydrofuran-d8 were determined as a function of the temperature and the solute concentrations. The determination of these chemical shifts was possible because in very pure samples the line positions are not affected by proton-exchange reactions. The data can only be explained by the presence of the following association reactions between hydrogen-bonded species which involve the solvent, S