On the affinities of ammonia and water for Li +, Na + and K +

Abstract

The affinities of ammonia for Na + and K +, recently determined experimentally, have been computed by the ab initio SCF method using e∈nded polarized gaussian basis sets and shown to be satisfactory Furthermore, the corresponding values computed at the same level of accuracy for the three cations Li +, Na +, K + and the two ligands NH 3 and H 2O are shown to yield the order Li + > Na + > K + for each ligand and NH 3 > H 2O for each ion, in agreement with experiment. An analysis of the factors involved in the binding provides a consistent rationalization of these regularities and of some observed correlations.