Infrared Photodissociation Spectroscopy of Mass-Selected Cu2O2(CO)n(+) Clusters in the Gas Phase.

The stoichiometric Cu2O2(CO)n+ (n = 3-7) clusters are generated via a laser vaporization supersonic cluster source in gas phase and identified by infrared photodissociation spectroscopy in the C-O stretching region. The infrared spectra are interpreted and the cluster structures are determined by density functional calculations. The ground state of Cu2O2(CO)n+ are intrinsically a dicopper superoxide carbonyl with [(OC)xCuOOCu(CO)y]+ ( x + y = n) structures in which CO ligands coordinate a zigzag Cu(OO)Cu+ core. The structure characterization for Cu(OO)Cu+ core-based clusters is crucial to correctively understand the associated catalytic reactions by metal clusters.