| Abstract: | Gas‐phase photoelectron spectroscopy (PES) was conducted on XAg24(SPhMe2)18]? (X=Ag, Au) and YAg24(SPhMe2)18]2? (Y=Pd, Pt), which have a formal superatomic core (X@Ag12)5+ or (Y@Ag12)4+ with icosahedral symmetry. PES results show that superatomic orbitals in the (Au@Ag12)5+ core remain unshifted with respect to those in the (Ag@Ag12)5+ core, whereas the orbitals in the (Y@Ag12)4+ (Y = Pd, Pt) core shift up in energy by about 1.4 eV. The remarkable doping effect of a single Y atom (Y=Pd, Pt) on the electronic structure of the chemically modified (Ag@Ag12)5+ superatom was reproduced by theoretical calculations on simplified model systems and was ascribed to 1) the weaker binding of valence electrons in Y@(Ag+)12 compared to Ag+@(Ag+)12 due to the reduction in formal charge of the core potential, and 2) the upward shift of the apparent vacuum level due to the presence of a repulsive Coulomb barrier between YAg24(SPhMe2)18]? and electron. |
