Structures of Bis(2-thiobarbiturato-O)tetraaquamagnesium and catena- [(μ_2-2-Thiobarbiturato-O,O)(2-thiobarbiturato-O) bis(μ_2-aqua)diaquastrontium] Monohydrate

摘要

The crystal structures of bis(2-thiobarbiturato-O)tetraaquamagnesium Mg(H_2O)_4(HTBA-O)_2 I and catena-[(μ_2-2-thiobarbiturato-O,O)(2-thiobarbiturato-O)bis(μ_2-aqua)diaquastrontiuin] monohydrate cate?a-[Sr(μ_2-H_2O)_2(H_2O)_2(μ_2-HTBA-O,O)(HBTA-O)]_n ? nH_2O (II), where H_2TBA is 2-thiobarbituric acid C_4H_4N_2O_2S, have been determined. Crystal data for a = 6.7598(2) A, 6 = 7.6060(2) A, c = 8.5797(2) A, α = 79.822(2)°, β = 76.622(1)°, γ = 69.124(1)°, V= 398.82(2) A~3, space group P, Z = 1; for II: a = 20.8499(4) A, b = 19.2649(5) A, c = 4.14007(9) A, p = 92.023(2)°, V= 1661.91(7) A~3, space group P2_1, Z= 4. The Mg~(2+) ion in I is bonded to six O atoms of two HTBA~- ions and four water molecules that form a nearly regular octahedron. Each Sr~(2+) ion in II is coordinated to three oxygen atoms of three HTBA~- ions and six water molecules that form an almost ideal tricapped trigonal prism. These polyhedra share edges to form infinite chains. Intermolecular hydrogen bonds create layered structures of I and II.