Multiparameter correlations for description of thermodynamic parameters of solvation: I. Enthalpy of nonspecific solvation

Applicability of a linear solvation-energy approach for descripition of the solvation enthalpies of nonelectrolytes is examined. In most cases a good fit of experimental solvation enthalpies can be attained. However, the resulting data are difficult to interpret in terms of different types of intermolecular interactions

Multiparameter correlations for describing thermodynamic parameters of solvation: II. Enthalpy of specific interaction

The applicability of the approach based on the linear solvation energy relationship to describing the enthalpies of specific solvent-solute interactions was examined. In associated solvents, this approach reflects the contribution of specific interaction incorrectly. Although the enthalpies of solvation as a whole are described well, this is an "occasional" result and is due to averaging over different compounds and redistribution of contributions from other types of interactions. A modification of this approach was suggested to take into account the effect of reorganization of an associated solvent

Photoinduced activation of arene C-H bonds with (η5-cyclopentadienyl)-trimethylplatinum(IV): A possible role of CpPtR2H

(η5-Cyclopentadienyl)trimethylplatinum(IV) reacts with ArMe arenes rather than alkanes or benzene under heating to 150 °C in the dark or under irradiation with light at room temperature by a radical mechanism to produce (η5-cyclopentadienyl)dimethyl(arylmethyl)platinum(IV) complexes, and the expected complex CpRR2(H) is unstable under the reaction conditions, as found by the reduction of CpRMe2I with complex metal hydrides

Thermochemistry of the solvation of organic non-electrolytes

This review surveys experimental data on the thermochemistry of the solvation of organic non-electrolytes. An analysis of the enthalpy of solvation as the sum of the enthalpies of non-specific solvation and of specific interaction is presented. The various methods for isolating the contribution of the enthalpies of the complex formation reactions between the solute and the solvent are examined. The role of the dipole moment of the solute molecule in solvation is analysed in detail. © 1991 IOP Publishing Ltd

Determining the Gibbs energies of hydrogen-bonding interactions of proton-accepting solutes in aqueous solutions from thermodynamic data at 298 K with regard to the hydrophobic effect

Reaction rate and equilibrium constants in aqueous solutions are affected by the strength of hydrogen bonds formed between dissolved species and water molecules. Thermodynamic functions of hydrogen bonding with bulk water cannot be measured directly using spectroscopic methods, but the contribution of hydrogen-bonding processes to the thermodynamic functions of hydration may be determined using some model of aqueous solutions. We determined the Gibbs energies of hydrogen-bonding interactions in water for various simple proton-accepting organic molecules on the basis of two different models that allow the contributions of nonspecific van der Waals interactions and the hydrophobic effect to be quantified. It is shown that hydrogen bonding with bulk water may be stronger than with a single water molecule. The influence of solute structure on the Gibbs energy of hydrogen-bonding interactions is discussed. © 2011 American Chemical Society

Thermodynamic description of the solvophobic effect in ionic liquids

© 2016 Elsevier B.V.The solvophobic effect is a driving force for self-assembly processes that acts in protic molecular organic solvents as well as in both protic and aprotic ionic liquids. It is known to reduce the solubility of apolar compounds and influence the magnitudes of thermodynamic functions of solvation in molecular solvents. In ionic liquids, thermodynamic aspects of the solvophobic effects have not yet been carefully considered. By comparing the relations between the Gibbs free energy and enthalpy of solvation of different compounds, we show that the solvophobic effect in aprotic ionic liquids can be even stronger than in organic solvents forming a network of intermolecular hydrogen bonds, such as formamide and ethylene glycol. The strength of the solvophobic effect expressed in terms of energy contributions is correlated with the average number of ions per unit volume, which is inversely proportional to the molar volume of the liquid. It is shown that the solvophobic effects become stronger when we change the cation or anion of the ionic liquid with another of a smaller size, and can be extremely weak when the cation contains long alkyl chains, but they are a general phenomenon for all ionic liquids

The hydrogen bonding enthalpies of water and methanol in ionic liquids

© 2018 Elsevier B.V. The thermochemical study of hydrogen bonding of water with different proton acceptor ionic liquids was carried out. Along with the available experimental data, the solution enthalpies of water in [BMIM][TfO], [BMIM][BF4] and [BMIM][PF6] were measured. The hydrogen bonding enthalpies of water with various ionic liquids were determined by using previously developed method of solvation enthalpy separation into the nonspecific solvation enthalpy and the specific solute-solvent interaction enthalpy (hydrogen bonding). The findings indicate the formation of a complex, where one molecule of water is bound to two molecules of ionic liquids. Similarly, hydrogen bonding enthalpies of methanol with the same proton acceptor ionic liquids were determined

Gibbs free energy of hydrogen bonding of aliphatic alcohols with liquid water at 298K

Thermodynamics of hydrogen bonding between water and molecules of aliphatic alcohols in dilute aqueous solutions is studied. The Gibbs free energies of hydrogen bonding of normal aliphatic alcohols from methanol to octanol with liquid water are determined from experimental data. The molar fractions of free unbonded molecules of alcohols and monomeric species of water are reported. Strong cooperative effects are observed when an alcohol molecule binds to an associate of water, leading to huge negative values of the Gibbs energies and an increased aqueous solubility. Formation of the second and third hydrogen bonds of an alcohol molecule with water is much less favorable, what can be described as an anti-cooperative effect. © 2011 Elsevier B.V

Solvophobic effects: Qualitative determination and quantitative description

Solvophobic effects strongly influence the thermodynamic properties of solutions and are one of the driving forces of self-assembly processes of supramolecular structures. However, the generally accepted definition and a quantitative measure of these effects have so far been absent. Based on the analysis of a large set of experimental data on the thermodynamic functions of solvation in various systems, we propose a qualitative criterion allowing us to judge about whether the solvophobic effects are manifested in the solution or not, and also a method to determine their contributions to the thermodynamic functions of solvation. A feature of the solvophobic effect is a violation of the linear relationship between the Gibbs free energy and the enthalpy of solvation, which is fulfilled for the solutions of different compounds in many non-associated solvents. It is shown that in self-associated solvents the solvophobic effect is observed for any dissolved compounds, including well soluble ones, resulting in an increase in the Gibbs energy of solvation. Previously proposed solvophobicity parameters are considered and compared with our results. © 2013 I. A. Sedov, B. N. Solomonov

A method for calculating the Gibbs energy of nonspecific solvation

A method for calculating the Gibbs energy of nonspecific solvation of nonelectrolytes was suggested. The new equation for the Gibbs energy of nonspecific solvation contains one solvent parameter that characterize nonspecific solvent-solute interactions and two experimental Gibbs energies of solvation in two standard solvents. The method is applicable to a wide range of solutes and solvents. It was successfully used to describe some 800 Gibbs energies of solvation for systems without specific solvent-solute interactions. © 2008 MAIK Nauka