The influence of the molecular dipole on the electronic structure of isomeric icosahedral dicarbadodecaborane and phosphacarbadodecaborane molecular films.

We compare the molecular films of three different isomers of closo-dicarbadodecaborane (orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), paracarborane (1,12-C2B10H12)) and two related icosahedral cage molecules, 1-phospha-2-carbadodecaborane (1,2-PCB10H11) and 1-phospha-7-carbadodecaborane (1,7-PCB10H11) adsorbed on a variety of substrates. While the experimental electronic structure from combined photoemission and inverse photoemission studies of the molecular films are in good agreement with semiempirical calculations for the isolated molecule, there is a shift in the chemical potential for each molecule. The experimental position of the molecular chemical potential implicates an influence of both interface and adsorbate dipole.

Comparison of K (+) and Li (+) ion scattering from Au nanoclusters deposited on SiOx.

The scattering of low energy alkali ions is used to probe the atomic and electronic structures of Au nanoclusters grown onto an untreated silicon (111) wafer. Charge-state-resolved time-of-flight spectra were collected for 2 keV (7)Li (+) and (39)K (+) as a function of Au coverage. The shapes of the spectra are interpreted in terms of the shadow cones formed by incoming Li (+) and K (+) . The differences in neutralization are interpreted in terms of the ionization potentials. The results indicate that nanoclusters displaying quantum size effects are formed upon the initial Au deposition, and they evolve to multilayer nanoclusters after a critical coverage has been reached. When sufficient Au is deposited, a thick film is formed with the properties of the bulk metal.