MOLECULAR-SOLVENT MODEL FOR A CRYPTATE SOLUTION IN ACETONITRILE - A HYPERNETTED-CHAIN STUDY

Hypernetted chain calculations are reported for pure liquid acetonitrile and for a 0.39 M acetonitrile solution of cryptate K+ 222, ClO4-. The obtained molecular correlations between solvent and solute particles are discussed in detail. It is found that the acetonitrile correlations are very similar in the pure liquid and in the solution. The solvation geometries around the cations and the anions are surprisingly unsymmetric and hence far from the picture which chemists currently use to describe ionic solvation. The theoretical results are compared to available wide-angle neutron scattering data for the pure liquid and to small-angle neutron scattering data for the cryptate solution. To our knowledge, this is the first integral equation study of molecular correlations in a real nonaqueous electrolyte solution.