Ligand-Protected Gold Alloy Clusters: Doping the Superatom

A density functional study of the experimentally observed ligand-protected gold alloy clusters PdAu(12)(PR(3))(8)Cl(4) and PtAu(6)Ag(6)(AgI(3))(2)(PR(3))(6) reveal the same stabilization mechanism as in ligand protected pure Au(N): the delocalized s-electron subsystem of a high symmetry metal core exhibits a shell closing. On the basis of this observation it is predicted that the substitution of a single Au atom in the well-known Au(25)(SR)(18) compound with Pd, Ag, and Cd will produce stable clusters resulting in a method to tune redox properties in such a nanoscale building block.