Solvent structure. The use of internal pressure and cohesive energy density to examine contributions to solvent-solvent interactions

Abstract

Internal pressures, (∂U/∂V)T, have been obtained at 25� for the solvents dimethyl sulphoxide, propylene carbonate, formamide, dimethylformamide, acetonitrile, methanol and hexamethyl-phosphoramide by measurement of the thermal pressure coefficients. Data in the literature suggest that values of the internal pressure and the cohesive energy density, (ΔU/Vm), are similar for a non-polar solvent. The observed divergence of the two properties in the polar solvents under investigation is discussed in terms of the nature of the solvent-solvent interactions.

Étude statistique des effets de solvant. III. Calcul et interprétation de paramètres empiriques de polarité à partir de propriétés physicochimiques des solvants purs

“…Dans un premier temps on tente, par une est dCfinie comme la variation d'knergie interne lors d'un exanalyse en composantes principales (12, 3 3 , de dtfinir les pansion elementaire du liquide, au cours de laquelle toutes les relations entre les variables, puis de les remplacer par des interactions entre molCcules (et en particulier les liaisons hyfacteurs qui en sont des combinaisons linkaires. Ensuite, on drogkne) ne sont pas rompues (23). P, traduit donc mieux la cherche si l'information associCe aux facteurs permet de rendre situation crCCe par l'introduction d'une molecule de solute, mais comme on n'en connait la valeur que pour un nombre insuffisant des solvants que nous Ctudions ici, nous avons utilisC 6.…”

Thermodynamic Study of Oxyethylated Glycols and Their Mixtures with Tertiary Carboxamides

“…The adequacy of Dack's concept [11] is confirmed by the fact that the inner pressure in nonpolar liquids where there are no other interactions than van der Waals is identical to cohesion (p i = D), while in nonelectrolytes associated by H bonds cohesion is much stronger. The total energy of intermolecular interactions in an individual liquid (U t ) as a sum of specific and nonspecific contributions [7] was calculated by Eq.…”

“…For this reason, the search for correlations between the thermochemical characteristics of solutions with the structure and properties of their components has been performed by qualitative correlation of the resulting data with published data for mixtures of tertiary amides with ethylene glycol [8], diethylene glycol [9], and triethylene glycol [10]. In view of the aforesaid, we considered it reasonable to begin with assessment of the structural state of each glycol and then compare these data in terms of a common model approach [11], proposed for analysis of intermolecular interactions in nonelectrolytes.…”

“…The above calculations enable us, using Dack's model [11] and inner pressure as a measure of nonspecilific interactions, to assess the contribution of such interactions in glycols [Eq. (4)].…”

Direct and Indirect Applications of Sub- and Supercritical Water in Food-Related Analysis

“…On the contrary, it has been suggested (Wiehe and Bagley 1967) that P int only reflects the breakage of non-specific intermolecular interactions as hydrogen bonds have been assumed not to be disturbed by an infinitesimal change in the fluid's volume (Dack 1975). Therefore, the ratio of the internal pressure to the cohesive energy density (n) may be viewed (Reichardt 2004) as a macroscopic-property-based reflection of the relative importance of specific interactions (H-bonding) in the overall solventsolvent intermolecular interactions.…”