Synthesis, Crystal Structure, and Vibrational Spectra of Ca4P6O19 (Trömelite) ‐ a catena‐Hexaphosphate

The catena–hexaphosphate Ca4P6O19 (Trömelite) was obtained by the reaction of calcium oxide with H3PO3 in a tube furnace at a temperature of 900 °C and crystallizes triclinic (space group P 1, Z = 2, a = 685.70(9) pm, b = 915.47(12) pm, c = 1282.25(17) pm, α = 109.602(10)°, β = 99.778(10)°, γ = 91.917(10)°, V = 743.70(17)·106 pm3). According to the powder diffraction data of Ca4P6O19 a Rietveld refinement of the lattice constants was performed; this confirmed the single–crystal data. Trömelite contains chains of six condensed corner‐sharing PO4 tetrahedra with the Ca atoms in the voids of the resulting structure. IR and Raman data of Trömelite are also presented.