Hydride-containing Ag- and Au-rich 8-electron superatomic icosahedral cores: a DFT investigation

Following several reports on ligand-protected atom-precise nanoclusters which encapsulate hydrides as interstitial dopants within their icosahedral core, the stability, structure and bonding of MH_x@Ag₁₂ and MH_x@Au₁₂ (M = Mo-Ag; W-Au) 8-electron cores is investigated through DFT calculations. The encapsulation of up to x = 3 hydrides appears to be possible but at the cost of substantial structural distortions. In most of the computed models, the hydrides are found nearly free to move inside their icosahedral cages. Systems with one (nido-type) or two (arachno-type) missing vertices on the icosahedron are also predicted to be viable. In general, the MH_x@Au₁₂ species appear to be of lower stability than their MH_x@Ag₁₂ homologs. We believe that this the work will provide some new directions for the synthesis of hydride-encapsulating superatoms.