Specific interactions of pyridinium ions and pyridine molecules in nitrobenzene. Substituent effects

A potentiometric study of (acid + base) equilibria in substituted 4-nitropyridine N-oxide systems in methanol and dimethyl sulfoxide

“…The equilibria of acid dissociation and cationic homoconjugation in non-aqueous solvents, in system formed by pyridine N-oxides have been studied by using a variety of experimental techniques, including UV-Vis, IR, NMR spectroscopies [12][13][14], conductometry [15][16][17], solubility [18] and potentiometric [19][20][21] methods. Also in this work, the potentiometric method was used as a basic technique for the investigation of (acid + base) equilibria.…”

Potentiometric studies of acid–base interactions in substituted 4-nitropyridine N-oxide systems

“…and cationic heteroconjugation equilibria (3) The above-mentioned equilibria in systems of mono-, di-and tri-substituted pyridine N-oxides have extensively been studied by using a variety of techniques such as conductometry [3][4][5], UV-Vis, IR and NMR spectroscopies [6][7][8], and the solubility method [9]. Actually, in spite of the relatively numerous experimental methods used for the determination of (acid + base) equilibrium constants, the commonly used one is the potentiometric method.…”