Tellurites of Hexavalent Uranium: First Observation of Polymerized (UO4)2- Tetraoxido Cores

Two novel Ca2(UO3)(TeO3)2 (1) and K2(UO2)2O2(TeO3) (2) uranyl tellurites were obtained from telluric acid, used as a starting reagent for both compounds. In 1, the tetraoxido core is coordinated by TeO3 groups and UO4 squares polymerize into [UO3] chains. The tetraoxido core coordination modes in compound 1 are unique. New layered ⋡2[(UO2)2(TeO3)O2]2– topology is observed for 2. Both of the compounds were studied by the means of high‐temperature X‐ray diffraction. The thermal decomposition of 1 and 2 is different and leads to formation of uranate compounds. Two novel Ca2(UO3)(TeO3)2 (1) and K2(UO2)2O2(TeO3) (2) uranyl tellurites were obtained from telluric acid. In 1, the tetraoxido core is coordinated by TeO3 groups and (UO4) squares polymerize into [UO3] chains. The tetraoxido core coordination modes in 1 are unique. A new layered ⋡2[(UO2)2(TeO3)O2]2– topology is observed for 2. Both compounds were studied by the means of high‐temperature X‐ray diffraction.