Binding in complex ionic systems: anticooperative effects in systems stabilized by electrostatic interactions

We compute the binding energies of complexes involving more than two molecular ions. More specifically, complexes constituted by acetate anions and either tetramethylammonium or sodium cations have been considered. Calculations have been performed at the ab initio HF and MP2 levels using the 6-31+G(d) basis set. Solvation effects have been represented by a continuum reaction field procedure.