Crystal and molecular structure of tetraaquabarium Di-μ-tartrato-di- μ-hydroxodigermanate(IV) pentahydrate [Ba(H2O)4] [Ge2(μ-Tart)2(μ-OH)2] • 5H 2O

A new heteronuclear germanium barium complex with D-tartaric acid [Ba(H2O)4][Ge2(μ-Tart)2(μ-OH)2]·5H2O (I) (H4Tart is tartaric acid) was synthesized. The identity of compound I and its com- position were determined by elemental analysis and X-ray diffraction. The thermal stability of the compound was studied; the coordination centers of the ligand were found from IR spectroscopy. The structure of I was determined by X-ray crystallography. Crystals I are tetragonal: a = 8.5033(2) Å, c = 30.9393(11) Å, V = 2237.10(11) Å3, Z = 4, space group P41, R1 = 0.0301 based on 4215 reflections with I > 2σ(I). In crystals I, neutral [Ge2(μ-Tart)2] dimers are linked in pairs by double hydroxyl bridges to form {[Ge2(μ-Tart)2(μ-OH)2]2−}∞ polymeric chains. Hydrated Ba2+ cations and crystal water molecules are in between the anionic chains. Polymeric complex anions, hydrated barium cations, and H2O molecules are bound by a system of hydrogen bonds to form a framework.