Na4SeO5, ein neues Pentaoxoselenat(VI) – Synthese,Charakterisierung und Vergleich mit isotypem Na4MoO5

Na₄SeO₅, a Novel Pentaoxoselenate(VI) – Synthesis, Charakterisation, and Comparison with Na₄MoO₅ Na₄SeO₅ was prepared by high pressure solid state reaction at 500 °C and at a hydrostatic pressure of 2.5 Gpa from a mixture of Na₂O and Na₂SeO₄ in silver crucibles and Na₄MoO₅ by solid state reaction at 450 °C from a mixture of Na₂O and MoO₃. The crystal structures of both new compounds were solved and refined using X‐ray powder methods (Profilematching Na₄SeO₅: P1, a = 988.3(1), b = 988.4(1), c = 558.6(1) pm, α = 96.25(1)°, β = 96.24(1)°, γ = 113.41(1)°, R_p = 0.0783, R_wp = 0.1037. Profilematching Na₄MoO₅: P1, a = 999.5(1), b = 1002.0(1), c = 565.1(1) pm, α = 96.54(1)°, β = 96.29(1)°, γ = 113.35(1)°, R_p = 0.0623, R_wp = 0.0867). Both compounds contain novel XO₅^4– anions of approximately tetragonal pyramidal shape. The crystal structures are consistent with spectroscopic data (IR, Raman).