Superhalogen Properties of Fluorinated Coinage Metal Clusters

Equilibrium geometries and ground state spin multiplicities of neutral and anionic coinage metal fluoride XFn clusters (X = Cu, Ag, and Au; n = 1−7) are obtained from density functional theory-based calculations. Our results show that in the case of neutral and anionic CuFn and AgFn clusters, a maximum of 4 F atoms (nmax = 4) can be bound atomically to the metal atoms, while remaining F atoms bind to the other F atoms to form F2 units. In contrast, a Au atom can bind up to six F atoms dissociatively. This contrasting binding scenario observed for these metal fluoride clusters is explained using the natural bond orbital analysis. The neutral XFn (X = Cu, Ag) clusters are stable against dissociation into X and F atoms up to n = 6, while AuFn clusters are stable up to n = 7. Similarly, with the exception of AgF7 and AuF6, all neutral clusters studied are stable against dissociation into F2 molecules. On the other hand, XFn− clusters are stable against dissociation into F atoms and F2 molecules over the entir...