The solvation of ions in acetonitrile and acetone: A molecular Ornstein-Zernike study

The solvation of alkali and halide ions in acetonitrile and acetone has been investigated via the molecular Ornstein-Zernike theory using the hypernetted chain approximation. Theoretical Gibbs solvation energies and solvation numbers are compared with experiments and numerical simulations. The calculated single-ion solvation energies are used to check the hypotheses serving to split-up the measured solvation energies of salts into their single-ion components. The solvation structure around the ions is discussed in detail and shown to be strongly influenced by the solvent-solvent spatial correlations. The calculated interionic potentials of mean force are presented and used to compute ion-ion association constants which are compared with experiment, The influence of the Lennard-Jones parameters of the ions upon the calculated properties is emphasized. (C) 1998 American Institute of Physics.