Structural chemistry and zeolitic properties of mixed oxalates with two open-framework types based on eight coordinate metals

Two families of open-framework materials have been obtained from the assembly of MO8 polyhedra and oxalate groups as building blocks. The compounds can be formulated as [MM′(C2O4)4]2−(M″y)2+ · (4 + x)H2O (y is 2 for monovalent M″ metals and 1 for divalent M″ metals), in which the sum of the valences of the two metals M and M′ involved in the anionic framework is six. The water molecules and counter cations, located in the voids of the structure, lead to zeolitic or cation dynamic properties.