Proton-Transfer Equilibria between Notrophenols and Alkylamines in N-Methylformamide

Article abstract of DOI:10.1021/j100237a025

The equilibrium constants, K_e, of the proton-transfer reactions between o-, m-, and p-nitrophenols (ONP, MNP, and PNP, respectively), and monomethylamine and di- and triethylamines (MNA, DEA, and TEA, respectively) in N-methylformamide (NMF) were measured spectrophotometrically by using amine-amine hydrochloride buffers at different temperatures and 0.1-0.2 M ionic strength.Together with the previously measured pK_a of p-nitrophenol, these values allowed the determination of the acidity constants of alkylamines and the other nitrophenols in this solvent.The reported values are compared with literature data in other media including the gas phase.The reaction enthalpies and entropies are also reported and discussed for some of these systems.