Combination between lacunary polyoxometalates and high-nuclear transition metal clusters under hydrothermal conditions: first (3,6)-connected framework constructed from sandwich-type polyoxometalate building blocks containing a novel (Cu8) cluster.

An unprecedented (3,6)-connected 3-D framework constructed from sandwich-type polyoxometalate building blocks containing a (Cu8) cluster, [Cu(H(2)O)(2)]H(2)[Cu(8)(dap)(4)(H(2)O)(2)(alpha-B-GeW(9)O(34))(2)] (dap = 1,2-diaminopropane) has been hydrothermally made, which provides a novel topological structure in transition metal substituted polyoxometalates.