Solvation of ions. XIX. Thermodynamic properties for transfer of single ions between protic and dipolar aprotic solvents

1974 ◽  
Vol 27 (3) ◽  
pp. 477 ◽  
Author(s):  
BG Cox ◽  
GR Hedwig ◽  
AJ Parker ◽  
DW Watts
Keyword(s):  
Thermodynamic Properties ◽  
Water Structure ◽  
Dimethyl Formamide ◽  
Aprotic Solvents ◽  
Free Energies ◽  
Enthalpy Changes ◽  
Solvation Of Ions ◽  
Anions And Cations ◽  
Solvent Molecules ◽  
Dipolar Aprotic Solvents

Standard molar free energies, enthalpies and entropies of transfer of some uni-univalent electrolytes from water to methanol, N-methylformamide, formamide, dimethyl sulphoxide, N,N-dimethyl- formamide, propylene carbonate, sulpholane, N-methylpyrrolidone and acetonitrile are presented. They have been divided into the corresponding thermodynamic properties for single ions by means of extrathermodynamic assumptions. Changes in the chemistry of anions on transfer from protic to dipolar aprotic solvents are mainly a function of enthalpy changes. There is a substantial loss of entropy on transferring both anions and cations from water to non-aqueous solvents. Entropies of transfer can be interpreted in terms of ordering and disordering solvent molecules and a uniquely extensive water structure. Evidence for solvation of the first and second kind in water is presented. Enthalpies of transfer from water are exothermic for cations but endothermic for many anions.

Solvation of ions. XXV. Partial molal volumes of single ions in protic and dipolar aprotic solvents

1975 ◽  
Vol 28 (5) ◽  
pp. 955 ◽  
Author(s):  
MRJ Dack ◽  
KJ Bird ◽  
AJ Parker
Keyword(s):  
Propylene Carbonate ◽  
Dimethyl Sulphoxide ◽  
Aprotic Solvents ◽  
Solvent Interactions ◽  
Partial Molal Volumes ◽  
Steric Crowding ◽  
Solvation Of Ions ◽  
Molal Volumes ◽  
Solvent Molecules ◽  
Dipolar Aprotic Solvents

Partial molal volumes at 25� are reported for some 1 : 1 electrolytes, and for triphenylmethane, in dimethyl sulphoxide, N,N- dimethylformamide, acetonitrile, propylene carbonate, formamide and hexamethylphosphoramide. The assumption that ΔV�tr(Ph4As+) = ΔV�tr(BPh4-) was used to obtain ionic partial molal volumes of transfer from water to the non-aqueous solvents. Solvent compressibility appears to determine the partial molal volumes of non-electrolytes and large hydrophobic ions in solution. Values of ΔV�tr for cations and anions are discussed in terms of ion-solvent interactions, solvent-solvent interactions and steric crowding of large solvent molecules around the ions.

Solvation of ions by dipolar aprotic solvents and water. A CNDO/2 study

1985 ◽  
Vol 50 (11) ◽  
pp. 2493-2508 ◽  
Author(s):  
Petr Kyselka ◽  
Zdeněk Havlas ◽  
Ivo Sláma
Keyword(s):  
Binary Mixtures ◽  
Quantum Chemical ◽  
Chemical Method ◽  
Molecular Structures ◽  
Dimethyl Sulphoxide ◽  
Ternary Mixtures ◽  
Aprotic Solvents ◽  
Quantum Chemical Method ◽  
Solvation Of Ions ◽  
Dipolar Aprotic Solvents

Solvation of Li+, Be2+, Na+, Mg2+, and Al3+ ions has been studied in binary mixtures with dimethyl sulphoxide, dimethylformamide, acetonitrile and water, and in ternary mixtures of the organic solvents with water. The CNDO/2 quantum chemical method was used to calculate the energies of solvation, molecular structures and charge distributions for the complexes acetonitrile...ion (1:1, 2:1, 4:1), dimethyl sulphoxide...ion (1:1), dimethylformamide...ion (1:1), and acetonitrile (dimethyl sulphoxide, dimethylformamide)...ion...water (1:1:1).

Octahedral cobalt(III) complexes in dipolar aprotic solvents. XIII. The isomerization of cis- and trans-Dibromobis(ethylenediamine)cobalt(III) ions, [CoBr2 em2]+, in anhydrous sulpholane

1968 ◽  
Vol 21 (3) ◽  
pp. 595 ◽  
Author(s):  
WR Fitzgerald ◽  
DW Watts
Keyword(s):  
Equilibrium Constants ◽  
Activation Parameters ◽  
Ion Pair ◽  
Pair Formation ◽  
Isomerization Reaction ◽  
State Entropy ◽  
Enthalpy Changes ◽  
Solvent Molecules ◽  
Cis And Trans ◽  
Dipolar Aprotic Solvents

The isomerization of cis- and trans-[CoBr2 en2]+ has been studied in anhydrous sulpholane (tetramethylene sulphone). No evidence has been found for the presence of species containing coordinated solvent molecules, and the mechanism of isomerization of both isomers is interpreted as SNl the rates being influenced by ion-pair formation. Activation parameters have been measured for the isomerization of both species at various bromide concentrations. Equilibrium constants and standard state entropy and enthalpy changes for the isomerization reaction and for the formation of the cis-[CoBr2 en2]+ .......Br- ion pair have been measured.

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