K3VO2(SO4)2: Formation conditions, crystal structure, and physicochemical properties

Potassium oxosulfatovanadate(V) K3VO2(SO4)2 has been obtained by solid-phase synthesis from K2SO4, K2S2O7, and V2O5 (2: 1: 1), and its formation conditions, crystal structure, and physiochemical properties have been studied. The conversions of K3VO2(SO4)2 in contact with potassium vanadates and other potassium oxosulfatovanadates(V) are considered in terms of phase relations in the K2O-V2O5-SO3 system, which models the active component of vanadium catalysts for sulfur dioxide oxidation into sulfur trioxide. The X-ray diffraction pattern of K3VO2(SO4)2 is indexed in the monoclinic system (space group P21) with unit cell parameters of a = 10.0408(1) Å, b = 7.2312(1) Å, c = 7.3821(1) Å, β = 104.457(1)°, Z = 2, and V = 519.02 Å3. The crystal structure of K3VO2(SO4)2 is built from [VO2(SO4)2]3− complex anions, in which the vanadium atom is in an octahedral oxygen environment formed by two terminal oxygen atoms (V-O(6) = 1.605(7) Å, V-O(10) = 1.619(7) Å and four oxygen atoms of the two chelating sulfate anions. The vibrational spectra of K3VO2(SO4)2 are analyzed using these structural data.