A Novel Framework Type for Inorganic Clusters with Cyanide Ligands: Crystal Structures of Cs2Mn3[Re6Se8(CN)6]2⋅15 H2O and (H3O)2Co3[Re6Se8(CN)6]2⋅14.5 H2O

Large cavities occupied by cations and water molecules are part of the polymeric inorganic cluster structure made up of [Re6Se8(CN)6]4− and M2+ ions (M=Mn, Co; see structure on the right). Remarkably, the water molecules play an essential role in the stabilization of the structure: When the cluster is heated to 80–160°C, water is lost irreversibly, and a sharp change in structure is observed.