Crystal Structures of Ammonium and Cesium Pentadecafluorotetraantimonates(III)

Abstract

Antimony(III) fluoride complexes with compositions (NH₄)₃Sb₄F₁₅(I) and Cs₃Sb₄F₁₅(II) are structurally characterized. Crystals Iare triclinic: a= 8.317(3) Å, b= 10.419(6) Å, c= 10.826(3) Å, α = 63.71(4)°, β = 73.24(3)°, γ = 77.42(5)°, Z= 2, ρ_calcd= 3.42 g/cm³, ρ_exp= 3.45 g/cm³, space group P $\overline {\text{1}}$, R= 0.051; crystals IIare monoclinic: a= 8.079(2) Å, b= 29.116(8) Å, c= 8.162(2) Å, β = 117.08(2)°, Z= 4, ρ_calcd= 4.549 g/cm³, ρ_exp= 4.50 g/cm³, space group P2₁/c, R= 0.036. Structure Iis composed of SbF₄E and SbF₅E polyhedra combined into tetranuclear chains; crystals IIconsist of SbF₄E polyhedra, two of which form a dimer Sb₂F₇E₂, while the other two are isolated (E is the antimony lone electron pair).