Tellurium Sulfates from Reactions in Oleum and Sulfur Trioxide: Syntheses and Crystal Structures of TeO(SO4), Te4O3(SO4)5, and Te(S2O7)2

Abstract

AbstractThe reaction of K2TeO4 with fuming sulfuric acid (65 % SO3) in sealed glass ampoules at 250 °C led to colorless single crystals of TeO(SO4) [triclinic, P$\bar{1}$, Z = 8, a = 819.89(3) pm, b = 836.95(4) pm, c = 1179.12(5) pm, α = 82.820(2)°, β = 70.645(2)°, γ = 81.897(2)°, V = 753.11(6) × 106 pm3]. A horseshoe type [Te4O3] fragment is the basic motif in the layer structure of the compound. The [Te4O3] moieties are linked to infinite chains by further oxide ions. Monomeric [Te4O3] horseshoes are found in the crystal structure of Te4O3(SO4)5 [trigonal, P3221, Z = 3, a = 859.05(2) pm, c = 2230.66(7) pm, V = 1425.61(6) × 106 pm3], which was obtained from TeO2 and fuming sulfuric acid (65 % SO3) at 200 °C as colorless single crystals. By switching to neat SO3 as reaction medium colorless crystals of Te(S2O7)2 [P21/n, Z = 4, a = 1065.25(3) pm, b = 818.50(2) pm, c = 1206.27(3) pm, β = 102.097(1)°, V = 1028.40(5) × 106 pm3] form when ortho‐telluric acid, H6TeO6, is used as the tellurium source. The compound was reported previously, however, obviously with a wrong crystallographic description. In the crystal structure the tellurium atoms are coordinated by two chelating disulfate ions. Further Te–O contacts link the [Te(S2O7)2] units to an extended network.