A new polymeric chain formed by paradodecatungstate clusters and [Cu(en)2]2+ complexes: hydrothermal synthesis and characterization of [Cu(en)2]3[{Cu(en)2}2(H2W12O42)]·12H2O

The hydrothermal reaction of the mixture of K2WO4·2H2O, CuSO4·5H2O, ethylenediamine and H2O at 170 °C for 72 h yields purple needle-like crystals of [Cu(en)2]3[{Cu(en)2}2(H2W12O42)]·12H2O. Single crystal X-ray diffraction reveals that the structure consists of one-dimensional [{Cu(en)2}2(H2W12O42)]n6n- anions with discrete [Cu(en)2]2+ complex cations and crystallization water molecules occupying the interchain positions. In the polymeric chain each paradodecatungstate [H2W12O42]10- cluster is connected to two neighbors through four µ2-[Cu(en)2]2+ complex groups. The magnetic measurements show that the compound possesses well-separated Cu2+ centers. A probe reaction of the oxidation of cyclohexane with 760 Torr of O2 indicates that the compound has good catalytic activity for the reaction.