Contributions to the stereochemistry of zirconium oxysalts—part VI: syntheses and crystal structures of K₂Zr(SO₄)₃∙2.5H₂O, K₂Zr(SeO₄)₃, K₂Zr₂O(SeO₄)₄, and Zr(OH)₂(SeO₄)·H₂O

The compounds K₂Zr(SO₄)₃·2.5H₂O, K₂Zr(SeO₄)₃, and K₂Zr₂O(SeO₄)₄ were synthesized at 200 °C by reaction of Zr₂O₂(CO₃)(OH)₂ and KHCO₃ with the respective acids H₂SeO₄/H₂SO₄ and minor H₂O. Zr(OH)₂(SeO₄)·H₂O originates from an analogous experiment at 215 °C without KHCO₃. All four phases form colorless crystals up to several tenths of a mm and were investigated by single crystal X-ray diffraction. K₂Zr(SO₄)₃·2.5H₂O is monoclinic, space group P2₁/c (No. 14), with a = 7.295(2) Å, b = 13.925(3) Å, c = 12.579(3) Å, β = 95.32(3)°, V = 1272.3(4) Å³, Z = 4, R1 = 0.025. K₂Zr(SeO₄)₃ and K₂Zr₂O(SeO₄)₄ are both triclinic, space group \(P\overline{1}\) $P\overline{1}$ (No. 2), with a = 7.570(1) Å, b = 10.500(1) Å, c = 14.400(1) Å, α = 85.55(1)°, β = 88.04(1)°, γ = 87.82(1)°, V = 1139.7(2) Å³, Z = 4, R1 = 0.049, and a = 5.400(1) Å, b = 7.328(1) Å, c = 9.642(1) Å, α = 95.81(1)°, β = 95.20(1)°, γ = 94.27(1)°, V = 376.74(4) Å³, Z = 1, R1 = 0.020, respectively. Zr(OH)₂(SeO₄)·H₂O crystallizes in the monoclinic space group C2/c (No. 15), with a = 6.684(1) Å, b = 12.998(2) Å, c = 6.792(1) Å, β = 97.37(1)°, V = 585.14(6) Å³, Z = 2, R1 = 0.013.