Mass spectrometric study of gas‐phase clustering reactions: Hydration of the monovalent bismuth ion

Thermodynamic properties of hydrated monobalent strontium ions in the gas phase were measured over the temperature range 38–400°C using high pressure mass spectrometry. Clusters up to 11 water molecules about a strontium ion were observed. The hydration enthalpies and entropies for the clusters, Sr(H2O)n, n?9 were derived from appropriate van’t Hoff plots. The exceptional stability of the clusters observed in the present study indicates the importance of valence electrons of the central ion in pormoting chemical bonding with the clustering water molecules.