Heteroatom-Doping Increases Cluster Nuclearity: From an [Ag ] to an [Au Ag ] Core.

A templated galvanic exchange performed on [Ag {Se P(OiPr) } ] of C symmetry with three equiv Au yields a mixture of [Au Ag {Se P(OiPr) } ] (x=0-2) from which [Au@Ag {Se P(OiPr) } ] and [Au@Au Ag {Se P(OiPr) } ] are successfully characterized to have T and C symmetry, respectively. Crystal structural analyses combined with DFT calculations on the model compounds explicitly demonstrate that the central Ag of Ag being oxidized by Au migrates to the protecting atomic shell as a new capping Ag , and both second and third Au dopants prefer occupying non-adjacent icosahedron vertices. The differences in symmetry, T and C , are manifested in the spatial orientation of their protecting atomic shell composed of eight capping Ag atoms as well as re-construction upon the replacement of Ag atoms on the vertices of AuAg icosahedral core with second and third Au dopants. As a result, a unique pathway for substitutional-doped clusters with increased nuclearity is proposed.