A 3D organic–inorganic network constructed from an Anderson-type polyoxometalate anion, a copper complex and a tetrameric [Na4(H2O)14]4+ cluster,

A rare three-dimensional organic–inorganic compound based on the Anderson-type polyoxometalate anion, [Na4(H2O)14Cu(PDA)2]H[Al(OH)6Mo6O18]·5H2O (H2PDA = pyrazine-2,3-dicarboxylic acid) (1) has been synthesized, in which each Anderson polyoxoanion [Al(OH)6Mo6O18]3− acts as a decadentate ligand, connecting four tetrameric [Na4(H2O)14]4+ clusters and two [Cu(PDA)2]2− coordination ions through terminal oxygen atoms.