SYNTHESIS, MOLECULAR AND CRYSTALLINE STRUCTURE OF THE TARTRATOGERMANATIC (IV) ANION- AND TRISBIPYRIDINEIRON CATION (II)-BASED COMPLEX

Abstract

Different metal and different ligand complex [Fe(bipy)3]2[{Ge(H2O) (μ-Tart)2Ge(H2Tart)}(S2O7)]*9Н2О (I) (H4Tart –tartaric acid, bipy – 2,2’-bipyridine) was obtained for the first time. The complex was characterized with the methods of elemental analysis and IR-spectroscopy, the thermal stability was also investigated. By the X-ray analysis it was identifi ed that I (CCDC 1576554) is complex compound of cation-anionic type in which [Ge(H2O) (μ-Tart)2Ge(H2Tart)]2- and S2O72- are anions, and cations – two iron complexes [Fe(bipy)3]2+. Coordination polyhedron of Ge1 is distorted square pyramid, in the base of which there are О2, О4, О8 and О10 atoms of tartaric acid, and in the top is O1 atom of water molecule. Value of Ge1-O bond length vary within the limits 1.756(9)1.938(13) Å, and values of the valence angles of O-Ge1-O vary in the limits 87.1(5)119.1(5). Polyhedron of Ge2 atom is distorted octahedron, formed with six oxygen atoms of three tartaric acids. In this, two molecules of tartaric acid with deprotonated both carboxylic and hydroxyl groups are bridging ligands between Ge1 and Ge2, and third molecule is terminal ligand, which has only one carboxylic and hydroxyl group. The ones, bonded with Ge2 atom, are deprotonated. Bond length of Ge2-O in the structure I vary within the limits 1.807(9)-1.972(7) Å , and valence angles vary within the limits 86.1(3)-99.3(4)°. In the crystal I anions are bonded with each other through forming of intermolecular hydrogen bonds and generate a three-dimensional net. In the cells of this net hydrophobic cation molecules are located. There are some characteristics of complex I comparatively to the previously studied tartratogermanates: in I two types of anions are presented – complex germanium-containing [Ge(H2O)( μ -Tart)2Ge(H2Tart)]2- and simple disulfate S2O7 2-; complex anion; contains two fully deprotonated bridging ligands Tart4- and one non-bridging deprotonated H2Tart2-; two germanium atoms in dimeric anion have different coordination polyhedron – distorted octahedron and square pyramid, which is formed because of nontypical for Ge(IV) coordination of water molecules.

Keywords

• германій
• винна кислота
• ферум(II) сульфат
• 2,2’-біпіридин
• координаційні сполуки
• кристалічна структура