COMPOUNDS CONTAINING LAYERS OF COMPOSITION [(SBIIIF)PO4], [(SBIIIF)AS4] - CRYSTAL-STRUCTURES OF NA(SBF)PO4.1.5H2O, NA(SBF)ASO4, NH4(SBF)PO4.H2O, AND NH4(SBF)ASO4.3H2O

The title compounds have been prepared in water by reaction of SbF3 with dihydrogen phosphates or arsenates and characterized by single crystal X-ray work, IR, Raman, and Mössbauer spectroscopy. They have identical layer structures. Layers of composition [(SbF)XO4]- (X = P, As) were formed by sharing four corners between XO4 tetrahedra and SbFO4 pseudooctahedra. The lengths of the terminal SbF bond (with the lone pair in a trans-position) and the SbO bonds are 192 and 219 pm, respectively. The stacking of the layers and the interlayer distance depend on the cations and the number of intercalated water molecules. In Na(SbF)AsO4 the Na+ ion is coordinated by only two oxygen atoms within 300 pm. Crystal data: Na(SbF)PO4 · 5H2O, monoclinic, P21 m, a = 656.2(5), b = 654.1(5), c = 867.9(3) pm, β = 92.43(1)°, 889 reflections, 81 parameters, R = 0.044, Rw = 0.046. NH4(SbF)PO4 · H2O, tetragonal, I4 m, a = 656.6(3), c = 1439.8(5) pm, 680 reflections, 31 parameters, R = 0.023, Rw = 0.021. Na(SbF)AsO4, tetragonal, P4 ncc, a = 671.8(1), c = 1756.4(4) pm, 1056 reflections, 28 parameters, R = 0.052, Rw = 0.065. NH4(SbF)AsO4 · 3H2O, tetragonal, P4 ncc, a = 683.8(2), c = 1873.0(7) pm, 1194 reflections, 30 parameters, R = 0.042, Rw = 0.050. © 1991.