Stability of small cationic platinum clusters

• The relative stability of small cationic platinum clusters is investigated by photofragmentation experiments. Mass spectra show a smooth intensity distribution except for a local intensity minimum at Pt-5(+), revealing enhanced stability of the platinum tetramer Pt-4(+). The possibility that radiative cooling competes with statistical fragmentation after photoexcitation is examined and it is shown that clusters in the N = 3-8 size range do not radiate on the time scale of the experiment. In the absence of radiative cooling, the mass spectra of photofragmented clusters can be well explained by dissociation energies computed using density functional theory. The large calculated HOMO-LUMO gap for Pt-4(+) (approximate to 1.2 eV) is attributed to its highly symmetric structure and provides an explanation for the surprisingly low reactivity of this cluster in different gas-phase reactions.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

collision-induced dissociation

bond-energies

reactivity

methane

dehydrogenation

temperature

superatoms

pathways

charge

dft

Chemistry

Physics

Publication and Content Type

ref (subject category)

art (subject category)