Mass Spectrometric Study of the Gas-Phase Hydration of the Monovalent Lead Ion

Thermodynamic properties of hydrated monovalent lead ions in the gas phase were measured over the temperature range 2–144°C using high‐pressure mass spectrometry. Clusters of up to eight water molecules about a lead ion were observed. The hydration enthalpies and entropies for the clusters, ${\mathrm{Pb}}^{+}({\mathrm{H}}_2\mathrm{O}{)}_m\text{, m≤ 6}$ , are derived from appropriate van't Hoff plots. The implication of the data in terms of the bonding of the small clusters and the distribution of lead ions in the atmosphere are discussed.