Solvation of ions—enthalpies, entropies and free energies of transfer

Parker, A. J.

doi:10.1016/0013-4686(76)85035-9

Cited by 145 publications

(58 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar behaviors have been reported for other solutes [6] [24]. It is wellestablished that H 2 O molecules surround a hydrophobic solute by the formation of a Hbonded network involving themselves [25], i.e., the solute is enclosed in a highly ordered H-bonded solvent cage (skin phase). This order increases in the H 2 O-rich zone by the addition of EtOH.…”

supporting

confidence: 52%

Effect of Preferential Solvation on the Thermodynamic Properties of Antidepressant Drug Trazodone in Aqueous Ethanol: Linear Free-Energy Relationships

Shehatta

2002

HCA

View full text Add to dashboard Cite

Dissociation constants (pK a ) of trazodone hydrochloride (TZD ¥ HCl) in EtOH/H 2 O media containing 0, 10,20,30,40, 50, 60, 70, and 80% (v/v) EtOH at 288.15, 298.15, 308.15, and 318.15 K were determined by potentiometric techniques. At any temperature, pK a decreased as the solvent was enriched with EtOH. The dissociation and transfer thermodynamic parameters were calculated, and the results showed that a nonspontaneous free-energy change (D diss G o > 0) and unfavorable enthalpy (D diss H o > 0) and entropy (D diss S o < 0) changes occurred on dissociation of trazodone hydrochloride. The free-energy change or pK a varied nonlinearly with the reciprocal dielectric constant, indicating the inadequacy of the electrostatic approach. The dissociation equilibria are discussed on the basis of the standard thermodynamics of transfer, solvent basicity, and solutesolvent interactions. The values of D trans G o and D trans H o increased negatively with increasing EtOH content, revealing a favorable transfer of trazodone hydrochloride from H 2 O to EtOH/H 2 O mixtures and preferential solvation of H and trazodone (TZD). Also, D trans S o values were negative and reached a minimum, in the H 2 Orich zone that has frequently been related to the initial promotion and subsequent collapse of the lattice structure of water. The pK a or D diss G o values correlated well with the Dimroth-Reichardt polarity parameter E T (30), indicating that the physicochemical properties of the solute in binary H 2 O/organic solvent mixtures are better correlated with a microscopic parameter than the macroscopic one. Also, it is suggested that preferential solvation plays a significant role in influencing the solvent dependence of dissociation of trazodone hydrochloride. The solute-solvent interactions were clarified on the basis of the linear free-energy relationships of Kamlet and Taft. The best multiparametric fit to the Kamlet-Taft equation was evaluated for each thermodynamic parameter. Therefore, these parameters in any EtOH/H 2 O mixture up to 80% were accurately derived by means of the obtained equations.

show abstract

supporting

confidence: 52%

Effect of Preferential Solvation on the Thermodynamic Properties of Antidepressant Drug Trazodone in Aqueous Ethanol: Linear Free-Energy Relationships

Shehatta

2002

HCA

View full text Add to dashboard Cite

show abstract

“…Previous theories [24,25] described the structure of water to be effectively polymeric and has a unique well-developed hydrogen-bonded structure of low entropy. On mixing methanol two factors contribute to the values of ∆H * and ∆S * , namely intercomponent bond formation and the bond breaking "depolymerization of water" with a disordering effect.…”

Section: Thermodynamic Treatment Of the Resultsmentioning

confidence: 99%

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Taha

2004

Port. Electrochim. Acta

View full text Add to dashboard Cite

The rate of copper II/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (CH 3 OH) and dimethyl sulphoxide (DMSO) has been studied and the reaction was found to follow first-order kinetics. The influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of Cu 2+ ions, temperature and concentration of organic solvent, was investigated. In the case of CH 3 OH, rotating zinc cylinder was used, while in the presence of DMSO stationary zinc sheet and rotating zinc cylinder were used. It was found that (1) the percentage inhibition caused by methanol ranged from 10.70 to 58.38 depending on the concentration of the alcohol used; (2) the rate of cementation in the presence of DMSO using rotating zinc cylinder > the rate of cementation in the presence of DMSO using stationary zinc sheet; (3) the rate of cementation on zinc cylinder in the presence of DMSO < the rate of cementation in the presence of CH 3 OH. Different reaction conditions, and the physical properties of solutions are studied to obtain dimensionless correlation among all these parameters. Thermodynamic parameters ∆S*, ∆H* and ∆G* were studied.

show abstract

“…Therefore, the large sigmoidal wave was separated into two sections with the first being used to describe TB À IT and the second for UO 2 2 + IT. Conventional evaluation of LSVs or cyclic voltammograms (CVs) obtained from liquid j liquid systems is to calibrate the potential scale using the TATB assumption [29,30] and known IT potentials; this technique is analogous to an internal standard method and in the present case TMA + IT was used as an internal reference, D w o f8' = 0.160 V [31]. First the electrochemical cell is scanned, then a known concentration of internal standard is added, and the system is scanned again.…”

mentioning

confidence: 99%

Evaluation of Gibbs Energy of Dioxouranium Transfer at an Electrified Liquid|Liquid Interface Supported on a Microhole

et al. 2011

View full text Add to dashboard Cite

Herein is reported the determination of the Gibbs energy of dioxouranium (UO 2 2 + ) transfer across an interface between two immiscible electrolytic solutions (ITIES), water and 1,2-dichloroethane, that was supported at a 25 mm diameter microhole, by means of linear sweep voltammetry. Through the use of minimal to no supporting electrolyte, this technique is able to observe ion transfer (IT) of extremely hydrophilic ions voltammetrically. As the applied potential in the aqueous phase became increasingly positive the UO 2 2 + ions were driven into the organic phase resulting in IT. The standard transfer potential, D w o f8' was determined to be 0.865 V through a novel curve fitting methodology applied directly to the voltammogram. The Gibbs energy of transfer was calculated to be 167 kJ·mol À1. Additionally, the kinetics of IT was explored using a Butler-Volmer model through finite element analysis, whereby the voltammetric current response owning to migration effects in the experimental CVs was approximated in the overlaid, simulated CVs using slow reaction kinetics.

show abstract

Solvation of ions—enthalpies, entropies and free energies of transfer

Cited by 145 publications

References 16 publications

Effect of Preferential Solvation on the Thermodynamic Properties of Antidepressant Drug Trazodone in Aqueous Ethanol: Linear Free-Energy Relationships

Effect of Preferential Solvation on the Thermodynamic Properties of Antidepressant Drug Trazodone in Aqueous Ethanol: Linear Free-Energy Relationships

Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder

Evaluation of Gibbs Energy of Dioxouranium Transfer at an Electrified Liquid|Liquid Interface Supported on a Microhole

Contact Info

Product

Resources

About