Crystal structure and properties of polymeric hexaaqua- hexakis-(2-thiobarbiturato)-disamarium(III).

The structure (CIF file CCDC No. 1401886) of the hexaaqua- hexakis(2-thiobarbiturato)-disamarium [Sm(HO)(HTBA)] polymeric complex ( I), where HТВА is 2-thiobarbituric acid, is determined; its thermal decomposition and IR spectrum are studied. The crystals of I are monoclinic: a = 14.072(1) Å, b = 10.0842(6) Å, c = 15.323(1) Å, β = 110.408(2)°, V = 2037.9(2) Å, space group P2/ n, Z = 2. All three independent thiobarbiturate anions HTBA coordinate to Sm through oxygen atoms. To one of independent Sm ions six (two terminal and four bridging) HTBA ions and two water molecules are coordinated; the second is bonded with four bridging HTBA and four water molecules, forming square antiprisms. The bridging HТВА-anions arrange antiprisms in layers. The structure is stabilized by hydrogen bonds and a π-π interaction between the HТВА ions. The topology of the polymer network of I is analyzed. [ABSTRACT FROM AUTHOR]