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

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