Crystal structures of two barium 2-thiobarbiturate complexes

Abstract

The crystal structures of [Ba(H2O)2(μ3-HTBA)2]n (I) and [Ba(μ2-H2O)(H2O)2××(μ4-HTBA)(HTBA)]n·2nH2O (II), where H2TBA is 2-thiobarbituric acid C4H4N2O2S, are determined. Crystallographic data are as follows: for I, a = 6.8730(1) A, b = 16.6640(2) A, c = 11.8504(2) A, V = 1357.24(4) A3, space group Pnma, Z = 4; for II, a = 9.134(1) A, b = 9.853(1) A, c = 10.020(1) A, α = 103.674(2)°, β = 99.491(2)°, γ = 101.683(2)°, V = 836.3(2) A3, space group \(P\bar 1\), Z = 2. In I, the Ba2+ ion coordinates 6 μ3-HTBA− ions and two terminal water molecules with the formation of a distorted square antiprism. The antiprisms are linked with each other into infinite chains by the edges of S atoms. In II, the Ba2+ ion coordinates four water molecules and 5 HTBA− ions forming a three-cap trigonal prism. Two BaO8S prisms have four common vertices of O atoms from two μ2-H2O and two μ4-HTBA−; they are organized into layers with other pairs. The structures are stabilized by intermolecular hydrogen bonds and the π-π-interaction of HTBA− ions.