Size dependent evolution of the electronic structure of small rhenium clusters investigated by photoelectron spectroscopy: approaching the bulk

The size dependent evolution of the electronic structure of isolated gas-phase rhenium clusters Ren− (n=2–40) is measured by photoelectron (PE) spectroscopy at 4.99 and 6.42 eV photon energies. For very small clusters the photodetachment threshold energies show a strong size dependence varying between 1.6 eV (Re2) and 2.6 eV (Re13). As for larger clusters, electron affinities (EA) increase smoothly toward bulk work function (WF). Bulk-like electronic features can already be observed around very small cluster sizes.