Correlations between Two and Three Protons

Intrinsic Binding Constants, Correlation Functions, and Corresponding Free Energies (in kcal/mol) for Various Carboxylic Acids  

The intrinsic binding constants were calculated from the experimental thermodynamic constants (see Section 2.3) as follows  

The pair and triplet correlations and the corresponding free energies are 

This isfarfrombeingnegligiblecompared with the values of W(l, 1, l)or W(l, 1). The source of this nonadditivity is not entirely clear. Since there is no major conformational change in the molecule, it has been attributed [e.g., by Saroff (1987)] to resonance energy and to solvent effects. 

Before speculating on the origin of the nonaddivity in the tricarboxylic acid, we note that the pair correlation in the cyclohexane-triamine is much stronger than the corresponding pair correlation in benzene-tricarboxylic acid—probably due to the shorter distances between the protons in the former. Furthermore, the nonaddi- 

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