Hydrothermal synthesis and crystal and molecular structure of a reduced, arsenic rich heteropolyanion, Na4[Mo4As6O20(OH)2]·9H2O

Abstract
The hydrothermal reaction of Na3MoO4·2H2O, Mo metal, MnO3, H5As3O10, NaCl and H2O in the mole ratio 6 : 6 : 6 : 3 : 10 : 166 for 110 h at 180 °C yielded orange crystals of the sodium salt of the arsenic-rich MoV–AsIII polyanion cluster, Na4[Mo4As6O20(OH)2]·9H2O.