M3V2B10O23 (M = Ca, Sr): two new vanadoborates with [V2B10O23]∞ double layers

Abstract

Two M₃V₂B₁₀O₂₃ (M = Ca, Sr) vanadoborates were synthesized by using a high-temperature solid-state technique for the first time. The single-crystal X-ray diffraction results showed that they both crystallized in the triclinic space group P, with unit cell parameters a = 6.525(3) Å, b = 11.462(4) Å, c = 12.714(5) Å, α = 114.126(10)°, β = 103.656(10)°, γ = 90.594(10)° for Ca₃V₂B₁₀O₂₃ and a = 6.639(2) Å, b = 11.571(4) Å, c = 12.998(4) Å, α = 114.333(3)°, β = 103.334(3)°, γ = 90.432(3)° for Sr₃V₂B₁₀O₂₃. Their main structural frameworks were observed to be novel “infinite” 2D [V₂B₁₀O₂₃]_∞ double layers composed of the [B₅O₉]_∞ infinite layers and VO₄ tetrahedra. Functional groups present in the M₃V₂B₁₀O₂₃ (M = Ca, Sr) samples were identified in their infrared spectra. Their thermal properties, UV-Vis-NIR diffuse-reflectance spectra and elements analyses are also presented.