Calorimetric investigations of hydrogen bonding in binary mixtures containing pyridine and its methyl-substituted derivatives. II. The dilute solutions of methanol and 2-methyl-2-propanol

Enthalpy of cooperative hydrogen bonding in complexes of tertiary amines with aliphatic alcohols: Calorimetric study

“…Thus, the measured solution enthalpies of methanol in 2-methylpyridine and in 3-methylpyridine are À3.72 ± 0.06 kJ Á mol À1 and À2.83 ± 0.04 kJ Á mol À1 , respectively. These data are similar to values À3.982 ± 0.016 kJ Á mol À1 for the system methanol-2-methylpyridine and À2.814 ± 0.013 kJ Á mol À1 for the system methanol-3-methylpyridine obtained in work [32].…”

“…We also compared the values of solution enthalpies obtained using our equipment with data of Heintz et al [32]. Thus, the measured solution enthalpies of methanol in 2-methylpyridine and in 3-methylpyridine are À3.72 ± 0.06 kJ Á mol À1 and À2.83 ± 0.04 kJ Á mol À1 , respectively.…”

“…The concentration ratio of free and bonded molecules changes, since B forms hydrogen bonds with O-H groups. This phenomenon was discussed in works [29][30][31][32]. It can be concluded, that determination of the enthalpy of cooperative hydrogen bonding of solute molecule with associated solvent clusters requires an accurate evaluation of reorganization term.…”

Association in Dilute Aqueous Solution of Pyridine and Its Methyl Derivatives Studied by Cryoscopic Method

“…Thus, the water molecule is bonded to one molecule of 2,6-dimethylpyridine, while its second proton can accept the electron pair of another molecule of H 2 O. Similar limiting molar enthalpies of solution of methanol and water in pyridine, monomethylpyridines, and 2,6-dimethylpyridine suggest that one molecule of water joins a single amine molecule through the O-H…N bond [3,6]. Thus, there are still water protons capable of the O-H…O bonding even in the amine-rich mixtures.…”

Viscosity of Associated Mixtures Approximated by the Grunberg-Nissan Model

“…Consequently, although neither water nor methanol are inert solvents for pyridine and its derivatives, the effects of mixing may be different. For example, the aggregation is manifested in the ultrasonic absorption and in the excess expansibility [1], while the first enthalpies of solution of water and methanol in pyridines are approximately independent of the solute [5]. That is because the latter function is sensitive mainly to the O-H· · ·N bond strength.…”