N. G. Ivanova

H/D Isotope Substitution Effect on the Structural and Thermodynamic Parameters of Intermolecular Interaction in Methanol at 278-318 K

The effect of H/D isotope substitution in methanol molecules on the geometrical parameters of the latter and the energetics of particle interactions is discussed in terms of scale particle theory and a model using internal pressure as a measure of nonspecific interactions in liquids. Deuteration leads to reduced space occupied by a molecule in the structural matrix of methanol. It is established that isotopic substitution differentiates the distribution of specific and van der Waals interactions. The former are strengthened and the latter weakened when protium is substituted by deuterium in a group forming hydrogen bonds, and the case is opposite when deuterium is replaced in the methyl radical of methanol.

Solubility and Thermodynamics of Solvation of Krypton in Mixtures of H/D Isotopomers of Water and Methanol at 101325 Pa and 278-318 K

The solubility of krypton in mixtures of H/D isotopomers of water (H2O, D2O) and methanol (CH3OH, CD3OH, CH3OD) was studied at 101325 Pa and 278.15-318.15 K with a 10 K step. The thermodynamic characteristics of Kr solvation were calculated. The densities of mixtures of water and methanol isotopomers at the examined temperatures were calculated with an error of no more than 1 × 10-5 g cm-3 in the entire composition range. Both in water and aqueous methanol, krypton behaves as a structure-making component, but the alcohol solvation surrounding of the Kr atoms is more labile and more susceptible to the breaking effect of temperature.

Effect of H/D-isotope substitution on the solubility and solvation thermodynamics of krypton in methanol solutions of carbamide

The solubility of gaseous krypton in CO(NH2)2—CH3OH (CD3OH) and CO(ND2)2—CH3OD solutions with carbamide concentrations of up to 1.5 solvomolality units (∼0.026 mole fractions) was measured at 278, 288, 298, 308, and 318 K and at a partial gas pressure of 101325 Pa. The thermodynamic functions of dissolution (solvation) of krypton and the standard Setchenov coefficients were calculated. The solvation of Kr molecules increases upon deuterium substitution and with an increase in the temperature and carbamide concentration. In these solutions, specific contacts between the carbamide and methanol molecules play the predominant role.