Structures of Platinum Oxide Clusters in the Gas Phase

The structures of small gas-phase PtnO2m+ (n =
1–6, m = 1, 2) cluster cations have been investigated
in a combined infrared multiple photon dissociation (IRMPD) spectroscopy
and density functional theory (DFT) study. On the basis of the infrared
spectra obtained, it is concluded that in most clusters oxygen is
bound dissociatively, preferring 2-fold bridge binding motifs, sometimes
combined with singly coordinated terminal binding. Comparison of the
oxide cluster structures with those of bare cationic platinum clusters
reported previously reveals major structural changes induced in the
platinum core upon oxygen binding. For some cluster sizes the presence
of the Ar messenger atom(s) is found to induce a significant change
in the observed cluster structure.