Enthalpy of solvation of butanediols in different solvents

The enthalpies of solution for 1,2-, 1,3-, 1,4- and 2,3-butanediol in water, formamide and dimethylsulphoxide were determined by calorimetry. From the results and data available in the literature for the enthalpy of vaporisation, the enthalpy of solvation was determined. The enthalpy of solvation was decomposed into two terms, cavity formation in the solvent to hold the solute and solute-solvent interaction.http://www.sciencedirect.com/science/article/B6THV-3Y9X8C1-2/1/b096193734aae40b777de9e3a0cf0f5

Structure of the 2-isopropylaminoethanol isolated molecule: Conformational analysis and intramolecular interactions

In this paper, a systematic exploration of all the possible conformers of 2-isopropylaminoethanol (2-IPAE) was carried out using the Density Functional Theory (B3LYP) and the 6-311++G(d,p) basis set. At this level, 66 unique conformers within a Gibbs energy range of ca. 31 kJ mol-1 were found in the potential energy surface and their geometrical and thermodynamic properties were determined and discussed. A significant molecular strain was evidenced by the dihedrals and distances between non-bonded hydrogen atoms. According to the geometrical parameters, a O-H···N hydrogen bond was found to be present in the three most stable conformers, representing 68% of the conformational composition at 298.15 K. The energetic and geometrical data derived from the DFT calculations were further complemented by a NBO analysis of the most stable conformers.http://www.sciencedirect.com/science/article/B6TGT-4SP3SK0-2/1/823e968aaafa83b518fa859a45fbcb5

On the interpretation of the enthalpy of solvation of hydroxyl cyclohexane derivatives in different solvents

Scaled particle theory was used for calculating the enthalpy of cavity formation in the solvation process of hydroxyl cyclohexane derivatives in water and in organic solvents. From the values calculated for the enthalpy of formation of the cavity and from those quoted for the enthalpy of solvation, the enthalpy of solute/solvent interaction was determined. This thermodynamic property shows that the formation of a cavity is an important contribution to the enthalpy of solvation, and is strongly dependent on the structure of the solvent. Unexpected results observed for water as compared with organic solvents are due to the differences in the cavity formation term rather than to solute/solvent interactions.http://www.sciencedirect.com/science/article/B6WHM-45FC659-3P/1/fa45ed4ff2b4aaea60be322822fe1b8