Photon-induced thermal desorption of CO from small metal-carbonyl clusters.
Thermal CO desorption from photoexcited free metal-carbonyl clusters has been resolved in real time using two-color pump-probe photoelectron spectroscopy. Sequential energy dissipation steps between the initial photoexcitation and the final desorption event, e.g., electron relaxation and thermalization, have been resolved for Au2(CO)(-) and Pt2(CO)5-. The desorption rates for the two clusters differ considerably due to the different numbers of vibrational degrees of freedom. The unimolecular CO-desorption thresholds of Au2(CO)(-) and Pt2(CO)5- have been approximated by means of a statistical Rice-Ramsperger-Kassel calculation using the experimentally derived desorption rate constants.
Lüttgens
G
G
Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Pontius
N
N
Bechthold
P S
PS
Neeb
M
M
Eberhardt
W
W