Syntheses and crystal structures of four new d0 transition metal tellurites

Abstract

Four new d⁰ transition metal tellurites, namely InVTeO₆ (1), β-InVTe₂O₈ (2), FeVTe₂O₈ (3), and Fe₂MoTe₂O₁₀ (4), were synthesized under hydrothermal conditions, and their crystal structures were determined using single-crystal X-ray diffraction. Compound 1 crystallizes in the noncentrosymmetric space group P2₁2₁2₁ (No. 19), with unit cell parameters of a = 5.0759(2) Å, b = 8.5030(3) Å, c = 11.6376(5) Å, V = 502.28(3) ų, and Z = 4, while the other three compounds crystallize in centrosymmetric structures, with space group Cmca and unit cell parameters of a = 7.0633(7) Å, b = 8.962(1) Å, c = 20.162(2) Å, V = 1276.3(2) ų, and Z = 8 for compound 2, space group P2₁/n and unit cell parameters of a = 7.8901(2) Å, b = 4.9617(1) Å, c = 16.4290(3) Å, β = 93.6198(8)°, V = 641.88(2) ų, and Z = 4 for compound 3, and space group Pnma and unit cell parameters of a = 8.7878(2) Å, b = 6.1327(2) Å, c = 15.2423(4) Å, V = 821.45(4) ų, and Z = 4 for compound 4. Compound 3 adopts a two-dimensional (2D) sheet structure composed of FeO₆ octahedra, VO₄ tetrahedra, and TeO₄ polyhedra. The other three compounds exhibit three-dimensional (3D) framework structures: Compound 1 is built from InO₆ octahedra, VO₄ tetrahedra, TeO₄ polyhedra; Compound 2 consists of InO₆ octahedra, VO₅ square pyramids, and TeO₃ polyhedra; and Compound 4 is composed of FeO₆ octahedra, MoO₆ octahedra, and TeO₃ polyhedra. The band structures, density of states, and electron localization functions of all four compounds were calculated. The vibrational spectra were examined for compounds 1, 2, and 4. Additionally, powder X-ray diffraction, element analysis, and thermogravimetric analysis were conducted for compound 4.