Stability and dissociation pathways of doped Au(n)X+ clusters (X = Y, Er, Nb).

Size dependent stabilities, fragmentation pathways and dissociation energies of a series of gas phase cationic doped gold clusters, Au(n)X+ (3 < or = n < or = 20; X = Y, Er and Nb), and pure Au(n)+ clusters were investigated in photofragmentation experiments. Size dependent stability patterns were obtained and the branching between monomer and dimer evaporation was studied. For bare gold, the competing neutral monomer and dimer evaporation channels were found to be in agreement with earlier studies.

The exchange coupling in Cr3On (n = 0-3) clusters.

The structures of neutral and cationic Cr3On0,+ (n = 0-3) clusters are calculated with density functional theory employing the BLYP and BP86 functionals. Gas-phase CrnOm clusters are produced by laser vaporization and characterized with time-of-flight mass spectrometry. The ionization energies of Cr3On (n = 0-2) are determined with threshold photoionization spectroscopy using tunable laser light in the 4.

To achieve stable spherical clusters: general principles and experimental confirmations.

General principles for designing stable highly symmetrical clusters are proposed. This approach takes advantage of both the extra stability of cage aromaticity and the good geometrical balance between the outer cage and the endohedral atom. The applicability of these design principles was confirmed by gas-phase experimental observations on group 14 element cages with endohedral Al's and also is illustrated by many literature examples of diverse systems.

Resonance and nonresonant laser ionization of sputtered uranium atoms from thin films and single microparticles: evaluation of a combined system for particle trace analysis.

The resonance and nonresonant laser ionization of uranium atoms sputtered from thin metal films and individual micrometer-size uranium oxide particles, respectively, was studied to evaluate a new setup for the analysis of actinide-containing micrometer-size particles. Experiments using nonresonant (193-nm) ionization of atoms and molecules sputtered from micrometer-size uranium oxide particles have shown that the uranium detection efficiencies for sputtered neutral atoms are approximately 2 orders of magnitude higher than for secondary ions. In uranium particles of 0.

Sigma aromaticity of the bimetallic Au5Zn+ cluster.

Experimental and theoretical evidence for a "sigma aromatic" bimetallic cluster is presented. A mass spectrometric analysis of AuNZn+ (N = 2-44) photofragments shows Au5Zn+ to be very abundant, proving its high stability. Calculations predict that Au5Zn+ has a planar geometry and six valence s electrons occupying delocalized sigma-bonded molecular orbitals in a manner similar to that of aromatic organic compounds, except for their nodal properties in the molecular plane.