THERMODYNAMIC DATA FROM FLUORESCENCE SPECTRA .2. HYDROPHOBIC BOND FORMATION IN BINARY COMPLEXES

Association constants for the formation of complexes between some phenolic compounds and sodium monocarboxylic acid salts have been determined at several temperatures by the method of fluorescence quenching. Some discussion is provided to support the validity of attributing deviations from Stern-Volmer kinetics, in these systems, to association. Assuming that complexes involving formate contain only a hydrogen bond, but that complexes involving higher homologs of formate contain both a hydrogen and a hydrophobic bond, subtraction of the thermodynamic parameters for hydrogen bonding from those for association in the higher homologs yields the thermodynamic parameters for the formation of pairwise hydrophobic bonds. These experimental values agree with those predicted from theory.