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

Abstract The compounds K 2 Zr(SO 4 ) 3 ·2.5H 2 O, K 2 Zr(SeO 4 ) 3 , and K 2 Zr 2 O(SeO 4 ) 4 were synthesized at 200 °C by reaction of Zr 2 O 2 (CO 3 )(OH) 2 and KHCO 3 with the respective acids H 2 SeO 4 /H 2 SO 4 and minor H 2 O. Zr(OH) 2 (SeO 4 )·H 2 O originates from an analogous experiment at 215 °C without KHCO 3 . All four phases form colorless crystals up to several tenths of a mm and were investigated by single crystal X-ray diffraction. K 2 Zr(SO 4 ) 3 ·2.5H 2 O is monoclinic, space group P 2 1 / 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) Å 3 , Z = 4, R 1 = 0.025. K 2 Zr(SeO 4 ) 3 and K 2 Zr 2 O(SeO 4 ) 4 are both triclinic, space group $$P\overline{1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>P</mml:mi> <mml:mover> <mml:mn>1</mml:mn> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> (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) Å 3 , Z = 4, R 1 = 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) Å 3 , Z = 1, R 1 = 0.020, respectively. Zr(OH) 2 (SeO 4 )·H 2 O crystallizes in the monoclinic space group C 2 /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) Å 3 , Z = 2, R 1 = 0.013. Graphical abstract