Two-dimensional (3, 6)-topological inorganic aggregate based on the sandwich-type polyoxometalate and lanthanide linkers

A new two-dimensional (2-D) inorganic aggregate, K3Na3{Nd2(H2O)12Cu4(H2 O)2(SiW9O34)2} · 21H2O (1), has been obtained by the reaction of divacant polyoxoanion [γ-SiW10O36], Cu2+, Nd3+ and Al3+ in the aqueous solution. X-ray diffraction analysis reveals that compound 1 represents the first 2-D inorganic aggregate composed of sandwich-type polyoxoanions and Ln cation linkers, and the first (3, 6)-topological network in the sandwich polyoxometalate chemistry. The 2-D layers in 1 are further connected into a three-dimensional (3-D) open framework by the potassium and sodium cations.