Synthesis, properties, and molecular and crystal structure of diantipyrylmethanium Bis(μ-tartrato)dihydroxydigermanate(IV) tetrahydrate (HDAm)2[Ge2(μ-L)2(OH)2] · 4H2O

The complex (HDam)2[Ge2(μ-L)2(OH)2] · 4H2O (I) (H4L is tartaric acid, Dam is diantipyrylmethane) was synthesized for the first time. The individual character and composition of I was established by elemental analysis and X-ray diffraction. The thermal stability of I was studied. The coordination sites of H4L in the germanium complex were determined by IR spectroscopy. The structure of I was determined by X-ray crystallography. The crystals of I are triclinic: a = 9.3098(10) Å, b = 9.8088(10) Å, c = 17.6869(10) Å, α = 84.009(10)°, β = 77.926(10)°, γ = 67.088(5)°, V = 1454.3(2) Å3, Z = 2, space group P 1 , R = 0.0628 for 6343 reflections with I > 2σ(I). The compound is composed of the complex anions [Ge2(μ-L)2(OH)2]2−, the HDam+ cations, and crystal water molecules. In the dimeric anion, the metal atoms are bound to two completely deprotonated ligands L4−. The latter are coordinated to the metal through the carboxyl (av. Ge-O, 1.911(6) Å) and hydroxyl (av. Ge-O, 1.768(6) Å) oxygen atoms. The coordination of each Ge atom is completed to trigonalbipyramidal by the O atom of the hydroxy ligand in the axial position (av. Ge-O, 1.748(7) Å). Both L4− ligands are D isomers. In the crystal, the complex anions and crystal water molecules are combined by a system of hydrogen bonds.