Combination of Lindqvist-type Tungstovanadates and Transition Metal Clusters under Hydrothermal Conditions

Two novel organic-inorganic heteropolyoxometalate compounds [{Cu(1,10- phen)OH}_2]_2[V_2W_4O_19]·6H_2O (1) and [Co(1,10-phen)_3]_2[V_2W_4O_(19)]·5H_2O (2) (1,10-phen = 1,10- phenanthroline) were hydrothermally synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Compound 1 contains a di-V substituted classical Lindqvist-type polyanion [V_2W_4O_(19)]~(4-), two dinuclear copper cations [{Cu(1,10-phen)OH}_2]~(2+) and six water molecules of crystallization. Two dinuclear copper cations [{Cu(1,10-phen)OH}_2]~(2+) consist of four transition metal coordination cations {Cu(1,10-phen)}~(2+), bridged by four hydroxyl groups. Meanwhile, both two dinuclear cations are grafted on the Lindqvist polyanion [V_2W_4O_(19)]~(4-) through two terminal oxygen (O(9)) and two μ_2-oxygen (O(6)) atoms. Such an unusual linking fashion is unique in the polyoxometalate chemistry. The basic framework of 2 is similar to that of 1 and contains one Lindqvist-type polyanion [V_2W_4O_(19)]~(4-), two six-coordinated cobalt cations [Co(1,10-phen)_3]~(2+) and five free water molecules.