Electronic structure of small copper oxide clusters: From Cu2O to Cu2O4

We study the electronic structure of copper oxide clusters, Cu2Ox (x=1-4), using anion photoelectron spectroscopy and density-functional calculations. The experiment is used to successfully guide a computational search for the cluster geometries. The predicted electron affinities at the obtained cluster structures reproduce exactly the trend observed experimentally. The definitive determination of the cluster structures enables a detailed analysis of the chemical bonding and electronic structure involving Cu atoms in different oxidation states exhibited by these clusters.