Effect of a localized charge on the stability of Van der Waals clusters

Abstract

The stability of anionic (SF 6)- N clusters (in the range of N< 23), generated in a supersonic expansion ion source with electron impact ionization, was investigated by measuring their blackbody induced radiative dissociation (BIRD) rates in an electrostatic ion beam trap (EIBT) at room temperature. The lifetime traces of EIBT-stored clusters were subjected to “master equation analysis” and the activation energies, E a , for the evaporation of a S F 6 monomer were extracted. We find that the decay rates of (SF 6)- N anionic clusters are larger than those of cationic SF + 5(SF 6)N-1 measured previously by the same method, and their corresponding activation energies to be smaller. These observations provide further insight into the effect of localized charge on cluster stability.