Coordination effects in hydrated manganese(II) 1,3-diethyl-2-thiobarbiturates and their thermal stability

Golovnev, Nicolay N.; Molokeev, Maxim S.; Sterkhova, Irina V.; Lesnikov, Maxim K.; Atuchin, Victor V. POLYHEDRON, 134 120-125; 10.1016/j.poly.2017.06.002 SEP 25 2017

Three new complexes of 1,3-diethyl-thiobarbituric acid (HDetba), barbiturate-bridged 2D Mn(II) polymer [Mn(H2O)2(Detba)2] (1), trinuclear [Mn3(H2O)10(Detba)6] (2) and discrete molecular [Mn(H2O)4(Detba)2]·H2O (3) are synthesized and structurally characterized by the X-ray single crystal technique. In 13, the Detba ions are coordinated to Mn(II) only through O atoms with manganese ions in the octahedral environment. In 1, the Mn(II) ion is coordinated by four μ2 bridge Detba ions and two terminal H2O molecules. In 2, the Mn1 ion is coordinated by three terminal H2O molecules, two terminal and one μ2 bridge Detba ion, and Mn2 is connected with two μ2-Detba ions and four H2O molecules. In 3, the Mn(II) ion is coordinated by two terminal Detba ions and four terminal H2O molecules. There are intermolecular hydrogen bonds O–H⋯O, O–H⋯S in the structures of 13 which form the 3D networks. Structure 2 is stabilized by the π–π interaction. The compounds thermal decomposition comprises dehydration steps and the organic ligand oxidation.