VSb(SeO₃)₄, first selenite containing V³⁺ cation: Synthesis, structure, characterization, magnetic properties, and calculations

A new vanadium antimony selenite, VSb(SeO₃)₄, has been synthesized through a solid-state reaction by using V₂O ₅, Sb₂O₃, and SeO₂ as reagents. The crystal structure of VSb(SeO₃)₄ has been solved and refined by single-crystal X-ray diffraction. Whereas the starting V⁵⁺ cation has been reduced to V³⁺, the Sb³⁺ cation has been oxidized to Sb⁵⁺ during the synthesis. VSb(SeO₃) ₄ has a three-dimensional framework structure consisting of V/SbO₆ octahedra and SeO₃ groups. The V³⁺ and Sb⁵⁺ cations are statistically disordered in the same site with 50% occupancy. The oxide ligands in SeO₃ groups are shared by V/SbO ₆ octahedra, and the framework expands outward radially from the center. The effective magnetic moment is estimated to be μ_eff = 2.57 μ_B per V³⁺ from the magnetic property measurements. The g-factor is determined to be g = 1.9(4) from the electron paramagnetic resonance spectrum, which is typical for a d² ion. The spin-polarized DFT+U calculations with U = 4 and 5 eV exhibit the magnetic moments of 1.98 μ_B and 2.01 μ_B, respectively, on V³⁺ ion. Infrared and UV-vis diffuse reflectance spectra, elemental analysis, X-ray photoelectron spectroscopy, thermal analysis, and electronic structure calculations are also reported.