title: Bridging behaviour of the 2-thiobarbiturate anion in its complexes with Li(I) and Na(I).
abstract: The structures of the Li(I) and Na(I) salts of 2-thiobarbituric acid (2-sulfanylidene-1-3-diazinane-4,6-dione, H2TBA) have been studied. μ-Aqua-octaaquabis(μ-2-thiobarbiturato-κ(2)O:O')bis(2-thiobarbiturato-κO)tetralithium(I) dihydrate, [Li4(C4H3N2O2S)4(H2O)9]·2H2O, (I), crystallizes with four symmetry-independent four-coordinated Li(I) cations and four independent HTBA(-) anions. The structure contains two structurally non-equivalent Li(I) cations and two non-equivalent HTBA(-) anions (bridging and terminal). Eight of the coordinated water ligands are terminal and the ninth acts as a bridge between Li(I) cations. Discrete [Li4(HTBA)4(H2O)9]·2H2O complexes form two-dimensional layers. Neighbouring layers are connected via hydrogen-bonding interactions, resulting in a three-dimensional network. Poly[μ2-aqua-tetraaqua(μ4-2-thiobarbiturato-κ(4)O:O:S:S)(μ2-thiobarbiturato-κ(2)O:S)disodium(I)], [Na2(C4H3N2O2S)2(H2O)5]n, (II), crystallizes with six-coordinated Na(I) cations. The octahedra are pairwise connected through edge-sharing by a water O atom and an O atom from the μ4-HTBA(-) ligand, and these pairs are further top-shared by the S atoms to form continuous chains along the a direction. Two independent HTBA(-) ligands integrate the chains to give a three-dimensional network.
authors.affiliation: Siberian State University, Svobodny 79, 660041 Krasnoyarsk, Russian Federation.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Golovnev
authors.forename: Maxim
authors.initials: M
authors.lastname: Molokeev
mesh_terms: D000838:Anions; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008094:Lithium / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*; D013858:Thiobarbiturates / Q000737:chemistry*
chemical_list: D000838:Anions; D056831:Coordination Complexes; D013858:Thiobarbiturates; D008094:Lithium; D012964:Sodium