Aluminum clusters: Ionization thresholds and reactivity toward deuterium, water, oxygen, methanol, methane, and carbon monoxide

Using the pulsed cluster beam flow reactor technique, we have measured the reactivity of aluminum clusters toward several molecules under thermal conditions. For each different molecule we observe that the reactivity exhibits a unique dependence on the number of aluminum atoms in the cluster. The overall reactivity of aluminum clusters toward different molecules is ordered roughly as O₂ > CH₃OH > CO > D₂O > D₂ > CH₄ with CH₄ showing no reaction under these experimental conditions. In addition, we are able to place upper and lower bounds on the ionization thresholds for the smaller aluminum clusters.