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.

It is shown that the oxidation with bromine of four aliphatic aldehydes to the corresponding carboxylic acids involves a rate-determining proton transfer. It is concluded that the aldehyde hydrate is the reactive entity in these oxidations.

The relative rates of the concurrent A1 and A2 hydrolyses of t-butyl acetate have been measured as a function of solvent composition in water-dimethyl sulphoxide (DMSO) mixtures. A large difference in solvent effect is observed, which correlates well with observed solvent effects on ethyl acetate (A2) and acetal (Al) hydrolyses in the same solvent system. Activity coefficients have been measured for t-butyl acetate, ethyl acetate, and acetal in various water-DMSO mixtures.

.The stability constants for Ag+ complexes of several diazapolyether ligands, L = (2,2,1), (2,1), (2,2) and (2) (Scheme 1), have been measured in acetonitrile and water mixtures. Rate constants for formation and dissociation of Ag(2,2,1)+, together with the free energies of transfer, ΔGtr, of (2,2,1) among the mixtures, are also reported, and are compared with corresponding values for the Ag+-(2,1,1) and Ag+-(2,2,2) systems. The solvent dependences of the stability constants and hence of ΔGtr(AgLCIO4) - AG,,(L) are almost identical for all systems, except for small differences at low water content between the behaviour of the bicyclic cryptand ligands [(2,2,2), (2,2,1), (2,1,1)] and the monocyclic and acylic ligands, attributable to effects of NH solvation in the latter group. The preferential solvation of Ag+ by acetonitrile in the mixtures results in a sharp decrease in the stability constants as acetonitrile is added to water, but the effect is partly compensated for by a corresponding decrease in the free energies of the complexes. A strong differentiation in the kinetic behaviour of the bicyclic cryptand ligands is observed. For (2,1,1) the formation rates are almost independent of solvent composition and the free energies of transfer of the activated complex, ΔG‡tr (Ag+. . .(2,1,1),ClO4-) closely parallels that of AgCIO4, whereas for the larger cryptands the formation rates show a stronger solvent dependence, and ΔG‡tr (Ag+. . .L,ClO4-) values much more closely resemble those of the stable complexes, ΔG‡tr (AgLClO4). It is suggested that for the smaller (2,1,1) ligand preferential solvation of Ag+ by acetonitrile still persists in the transition state, but that in the activated complex for (2,2,1) and (2,2,2) the strong interactions between Ag+ and the ligand nitrogens have already replaced the Ag+. . .N≡CCH3 interactions occurring for the uncomplexed Ag+ ion in the mixtures.

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