Three-Dimensional Open Framework Built from Cu-S Icosahedral Clusters and Its Photocatalytic Property

Reported here is an extraordinary and unprecedented sulfide containing icosahedral [Cu8S12](16-) clusters that behave like a pseudo-octahedral unit in the bonding pattern and are linked through two monomeric GeS44- and four dimeric Ge2S64- units into a covalent 3-D open framework. Its large Cu to Ge ratio is highly unusual in 3-D open-framework sulfides and contributes to its low electronic band gap and the visible light photocatalytic activity.