Structure of the Ligated Ag60 Nanoparticle [{Cl@Ag12}@Ag48(dppm)12] (where dppm=bis(diphenylphosphino)methane)

A novel bisphosphine ligated Ag-60 nanocluster, [{Cl@Ag-12}@Ag-48(dppm)(12)] , has been discovered and characterized by X-ray crystallography. It consists of a central chloride located inside an icosahedral silver core layer, which is further encased by a second shell of 48 silver atoms/ions, which are capped with 12 bis(diphenylphosphino)methane (dppm) ligands. Due to lack of sufficient material the cluster could not be further characterized by other methods. DFT calculations were carried out on the cation [{Cl@Ag-12}@Ag-48(dppm)(12)](+) to determine if it corresponds to a superatom with a core count of n=58. The DFT optimized structure is in agreement with X-ray findings, but the low value of the HOMO-LUMO gap does not support superatom stability.