Thermodynamics of transfer of cryptand 222 from water to non-aqueous solvents and of protonated cryptand 222 from water to methanol
Abstract
Gibbs energies of transfer of cryptand 222 from water to methanol, octan-1-ol, acetonitrile, propylene carbonate, dimethylsulphoxide, dimethylformamide and n-tetradecane are reported. Values, on the molar scale, are small, being mostly only 1–2 kcal mol–1. Combination with previously reported enthalpies of transfer yield standard entropies of transfer from water. The latter are very large and positive, and arise, it is suggested, through loss of substantial hydrogen bonding in water. A thermodynamic cycle yields ΔG°t, ΔH°t and ΔS°t for transfer of mono- and di-protonated cryptand 222 from water to methanol.