Lithium, Sodium, and Strontium Fluoroglutaratouranylates: Structure and Some Properties

The structure of the crystals of Li(UO₂)₂(C₅H₆O₄)₂F‧6H₂O (I), NaUO₂(C₅H₆O₄)F‧4H₂O (II), and Sr(UO₂)₂(C₅H₆O₄)₂F₂‧8H₂O (III) was studied by X-ray diffraction analysis for the first time. The uranium-containing structural units in crystals of I are 1D complexes [UO₂(C₅H₆O₄)F_0.5(H₂O)]^0.5– with the crystal chemical formula AQ⁰²M²_0.5M¹, where A = UO₂²⁺, Q⁰² = C₅H₆O₄^2–, M² = F^–, M¹ = H₂O, and in II and III, 1D complexes of the same composition and structure [UO₂(C₅H₆O₄)F]^– with the crystal chemical formula AQ⁰²M². In all compounds, the U(VI) atoms implement hexagonal-bipyramidal coordination, forming coordination polyhedra UO₂FO₅ (I) and UO₂F₂O₄ (II and III). It was found that the uranyl fluoroglutarate {UJUBEG}, for which the composition [UO₂(С₅H₆O₄)F]‧2H₂O contradicting the of electroneutrality principle was previously erroneously indicated, should be considered as (Н₃O)[UO₂(С₅H₆O₄)F]‧H₂O.