Enthalpies of interaction of polar and nonpolar molecules with aromatic solvents

Abstract

. Can. J. Chem. 60, 1953Chem. 60, (1982. Enthalpies of solution of representative ketones, phenols, alcohols, and ethers have been determined in a,a,a-trifluorotoluene, benzene, toluene, and mesitylene, and combined with heats of vaporization to give enthalpies of transfer from vapor to the aromatic solvents [AH(v+S)]. Comparison of these values with AH(v-+S) of nonpolar model compounds provides an estimate of the special interactions (dipole -induced dipole or charge transfer, and hydrogen bonding) of the polar solutes with each aromatic solvent. Unless the model compound is perfectly matched, an alternative procedure, the pure base method, is superior for evaluating hydrogen bonding.The special interactions of ketones and ethers with aromatic solvents increase with decreasing x electron density of the solvent.By contrast, m-cresol shows the strongest special interaction with the most electron-rich solvent (mesitylene > toluene > benzene > trifluorotoluene). These results demonstrate that -OH and -OR groups undergo quite different interactions, and that a distinctive interaction occurs between the hydroxyl group and the aromatic ring.Calorimetric heats of vaporization have been measured for the solutes n-butyl ether (10.68 + 0.02kcal/mol), 2,2,4,4-tetramethylpentane (9.20 + 0.03), n-pentane (6.36 0.02), 1-butanol (12.46 + 0.00), and 2-methyl-2-butanol(11.94 + 0.02). On a mesure par calorimttrie les chaleurs de vaporisation des solutes: ether 11-butylique (10,68 + 0,02 kcal/mol), tetramethyl-2,2,4,4 pentane (9,20 + 0,03), 11-pentane (6,36 + 0,02), butanol-1 (12,46 + 0,OO) et methyl-2 butanol-2 (1 1.94 +_ 0,02).[Traduit par le journal]

Solution calorimetry of organic nonelectrolytes as a tool for investigation of intermolecular interactions

“…Solution and solvation of alkanes in various media were studied thermochemically in a series of works. [62,[78][79][80][81] It was ascertained that solvation enthalpy of alkyl derivatives of various substances is the additive function of the number of methylene groups in solute molecule. [62,80] Besides, it was shown in References [78,82] that solution enthalpy for alkanes of various structure is proportional to the volume of alkane molecule.…”

“…Examples of such proportional dependences are shown in Fig. 1, where the solution enthalpy values were obtained from References [62,[78][79][80][83][84][85][86][87][88][89] .…”

“…Solutes: 1 -n-pentane, 2 -n-hexane, 3n-heptane, 4 -n-octane, 5 -n-nonane, 6 -n-decane, 7 -n-undecane, 8n-dodecane, 9 -n-tetradecane, 10 -n-hexadecane. D soln H Alk=S and MR Alk values taken from References [62,[78][79][80][83][84][85][86][87][88][89] only with calorimetric, [91] but also with IR spectroscopic data. [92,93] The solvent effect on the stretching vibration frequencies of different bonds of the solute was successfully described using this parameter.…”

Solute−Solvent Complex Kinetics and Thermodynamics Probed by 2D-IR Vibrational Echo Chemical Exchange Spectroscopy

“…The typical organic solute-solvent interaction energy is weak, less than 5 kcal/mol. 3 This value suggests that the dissociation time scale of solute-solvent complexes in room temperature solutions will be faster than 1 ns. 4 However, complexes that exist for even short times, ten to a hundred picoseconds, fundamentally change the behavior of a solvent surrounding a solute.…”

A method to determine the Gibbs energy of specific interactions in solutions. Hydrogen bonding of proton donating solutes in basic solvents

“…There were several works aimed to quantify the specific interaction enthalpy between solute and solvent in infinitely diluted solutions of nonelectrolytes from calorimetric data [4][5][6][7][8][9]. It was found that the specific interaction enthalpies of H-donors in basic solvents are close to the enthalpies of 1:1 hydrogen bonding complexation in tetrachloromethane even for most polar bases [4].…”