Electron Binding in a Superatom with a Repulsive Coulomb Barrier: The Case of [Ag(SCHF)] in the Gas Phase.

The electron binding mechanism in [Ag(SCHF)] (SCHF = 3,4-difluorobenzenethiolate) tetra-anion was studied by photoelectron spectroscopy (PES), collision-induced dissociation mass spectrometry (CID-MS), and density functional theory (DFT) computations. PES showed that [Ag(SCHF)] is energetically metastable with respect to electron autodetachment {[Ag(SCHF)] + e} and features a repulsive Coulomb barrier (RCB) with a height of 2.7 eV.

Characterization of chemically modified gold and silver clusters in gas phase.

Atomically precise Au and Ag clusters protected by organic ligands can be viewed as chemically modified Au/Ag superatoms and have attracted interest as promising building units of functional materials and ideal platforms for studying the size-dependent evolution of structures and properties. Their structures, stability, and physicochemical properties have been characterized in solution and solid (or crystalline) phases by various methods conventionally used in materials science. However, novel and complementary information on their intrinsic stability and structures can be obtained by applying a variety of gas-phase methods, including mass spectrometry, ion mobility mass spectrometry, collision- or surface-induced dissociation mass spectrometry, photoelectron spectroscopy, and photodissociation mass spectrometry, to the chemically modified Au/Ag superatoms isolated in the gas phase.

Elucidating the Doping Effect on the Electronic Structure of Thiolate-Protected Silver Superatoms by Photoelectron Spectroscopy.

Gas-phase photoelectron spectroscopy (PES) was conducted on [XAg (SPhMe ) ] (X=Ag, Au) and [YAg (SPhMe ) ] (Y=Pd, Pt), which have a formal superatomic core (X@Ag ) or (Y@Ag ) with icosahedral symmetry. PES results show that superatomic orbitals in the (Au@Ag ) core remain unshifted with respect to those in the (Ag@Ag ) core, whereas the orbitals in the (Y@Ag ) (Y = Pd, Pt) core shift up in energy by about 1.4 eV.