Zur kristallchemischen Einordnung von NaSbCl6, NaNbCl6und NaTaCl6

From single-crystal X-ray diffraction data collected at room temperature the structures of three sodium salts have been established. While NaSbCl6 is tetragonal with a = 6.393(2) Å and c = 10.717(3) Å (space group P42/m, Z = 2), the niobium and tantalum analogues crystallize both in the monoclinic space group P21/c with lattice parameter c doubled and Z = 4 [NaNbCl6: a = 6.398(2) Å, b = 6.850(2) Å, c = 19.012(6) Å, β = 90.72(2)°; NaTaCl6: a = 6.449(2) Å, b = 6.880(2) Å, c = 18.989(6) Å β = 90.87(2)°]. Structure refinement includes corrections for absorption and extinction. The final R values are 0.017 (NaSbCl6, 611 refl.), 0.018 (NaNbCl6, 2214 refl.), and 0.024 (NaTaCl6, 2341 refl.).