Sequential Bond Energies of Water to Na^+ (3s^0), Mg^+ (3s^1), and Al^+ (3s^2)

Thresholds for collision-induced dissociation of M^+(H_2O), (x = 1-4, M = Na, Mg, and Al) with xenon are measured by using guided ion beam mass spectrometry. In all cases, the primary product is endothermic loss of one water molecule. The cross-section thresholds are interpreted to yield 0 K bond energies after accounting for the effects of multiple ion-molecule collisions, internal energy of the clusters, and dissociation lifetimes. Our results are in good agreement with previous experimental results for Na^(H_2O)_x, and in reasonable agreement with theoretical predictions for all systems. Trends in bond dissociation energies with increasing ligation and for the various metals studied are discussed.