Fast reactions involving hydrogen bonding in 2,2-disubstituted malonic acids

Rate constants have been obtained by the temperature-jump method for acid-base reactions of 2,2-disubstituted malonic acids in aqueous solution. Differences of rate constants for a given reaction have been correlated with the effects substituent groups have on the intramolecular hydrogen bond. Activation energies, enthalpies, and entropies have been calculated which indicate that the substituent effect is primarily steric in nature. The acid dissociation constants for these substances were determined by potentiometric titrations at 0.1 M ionic strength and 25°.