Structures of molecular adducts of inorganic salts. V. Non-centrosymmetric 2 Sr(ReO4)2 · 3 Urea · 2 H2O 1

Abstract

Abstract 2 Sr(ReO4)2 · 3 (NH2)2CO · 2 H2O, M = 1308.15. Orthorhombic, a = 19.386(2) Å, b = 34.229(4) Å, c = 7.697(2) Å, V = 5107(2) Å3, space group Fdd2 (No. 43), Z = 8, Dx = 3.402g · cm−3, μ(MoKα ) = 23.25 cm−1, R = 0.023 for 1144 reflections with I > 2σ(I). The structure of 2 Sr(ReO4)2 · 3 Urea · 2 H2O consists of ∞ 2[M2T4 · 3 Urea] · 2 H2O layers composed of doubled chalcanthite-like ribbons connected by triple M – O – M (O = urea oxygen atom) bridges and decorated on both sides by ReO4 tetrahedra and water molecules. The layers are held together by H-bonds only. The coordinate polyhedron of Sr is a highly distorted dodecahedron with Sr – Oave = 2.603(10) Å. The polyhedra are coupled by sharing a face of urea oxygen atoms.