Properties and nature of interactions in Cl-(H2O)n n=1,6 clusters:: a theoretical study

A series of Cl-(H2O)(n) complexes has been studied using ab initio post-Hartree-Fock methods. The arrangement of water molecules around the chloride ion in the Cl-(H2O)(n) clusters reveals the competition between the solvation of an anion and the hydrogen bonding between solvent molecules. The larger studied clusters (n = 5,6) possess water molecules in the second solvation shell. Experimental electron affinities together with experimental dissociation energies of ionic clusters were used to estimate the properties of neutral Cl(H2O)(n) complexes. The partitioning of the interaction energies in ionic Cl-(H2O)(n) clusters indicates the dominant character of the electrostatic forces. (C) 2000 Elsevier Science B.V. All rights reserved.