Browsing by Author "Thain, Jennifer M."

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    Nuclear magnetic resonance studies of preferential solvation: Part 3.—Thermodynamic treatment involving change of solvation number, and application to dimethyl sulphoxide-containing solvents
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (10), 1974) Covington, Arthur K.; Lantzke, Ian R.; Thain, Jennifer M.
    Studies of 7Li and 133Cs ion n.m.r. chemical shifts in dimethyl sulphoxide (DMSO)+ water mixtures, have been interpreted in terms of a series of competitive equilibria in which the solvation number of the ions for DMSO is half that for water. It is concluded that nitrate ions are preferentially solvated by DMSO and Li+ by water. The treatment has also been applied to 133Cs shift data for sulpholan and water mixtures, and it is concluded that caesium ions are solvated by the organic component.
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    Nuclear magnetic resonance studies of preferential solvation: Part 4.—Thermodynamic treatment involving non-statistical distribution of solvated species
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (10), 1974) Covington, Arthur K.; Thain, Jennifer M.
    The solvation of an ion in a binary solvent mixture has been treated in terms of consecutive stepwise equilibria with the solvent exchange process becoming more, or less, energetically favourable as the solvation shell becomes successively richer in the second component. Equations developed can be used to fit a wide range of observed n.m.r. chemical, and u.v. peak maximum, shift results in mixed solvents, such as dimethyl sulphoxide + H2O, acetonitrile + H2O, ethylenediamine + water. A classification of the observed behaviour is presented in terms of two parameters, K1/n(K1/n > 1 preferential solvation by second component, where n is the solvation number) and k(1.5 > k > 0.5). It is concluded that Cs+, NO–3, I– are preferentially solvated by DMSO and Li+ slightly preferentially solvated by H2O, in DMSO + H2O mixtures. In acetonitrile + H2O mixtures, Na+, Cl–, Br–, I– are preferentially hydrated.