(C2H10N2)[BPO4F2] — Structural Relations between [BPO4F2]2— and [Si2O6]4—

(C₂H₁₀N₂)BPO₄F₂] — Strukturbeziehungen zwischen BPO₄F₂]^2— und Si₂O₆]^4— Colourless crystals of (C₂H₁₀N₂)BPO₄F₂] were prepared from mixture of ethylendiamine, H₃BO₃, BF₃ · C₂H₅NH₂, H₃PO₄ and HCl under mild hydrothermal conditions (220 °C). The crystal structure was determined by single crystal methods (triclinic, P1¯ (no. 2), a = 451.85(5) pm, b = 710.20(8) pm, c = 1210.2(2) pm, α = 86.08(1)°, β = 88.52(2)°, γ = 71.74(1)°, Z = 2) and contains infinite tetrahedral zweier‐single‐chains {BPO₄F₂]^2—} which are isoelectronic (48e^—) with the polyanions {Si₂O₆]^4—} of the pyroxene family.