Crystal structure of ammonium oxo(peroxo)(pyridine-2,6-dicarboxylato- N,O,O′)aquavanadate(V), (NH4)[VO(O2)(H2O)(C7H3NO4)]

Abstract

Source of materialDark red crystals suitable for X-ray diffraction analysis were obtained by keeping at 253 K a 1:1:1 (molar ratio) mixture of ammonium vanadate, NH 4VO3, pyridine-2,6-dicarboxylic acid, C 7H5NO4, and hydrogen peroxide in a water-ethanol mixture. DiscussionIn the frame of research aimed at developing new synthetic procedures of oxide materials, the so-called chelate method, which consists in the thermal decomposition of solid metal precursors obtained from a solution of the complexed metals, was shown to be an appropriate way to get multimetallic oxides [1,2]. During investigations to identify new water-soluble vanadium compounds that could be used as precursors for V-based oxides, the title compound was isolated. In our analysis, we do not observed any water molecule in the unit cell and the structure of the [VO(O 2)(H2O)(C7H3NO4)] -anion is similar to that reported in [3] but with a more precise geometry. The vanadium coordination polyhedron is a pentagonal bipyramid with the peroxo and dipicolinato ligands being bidentate and tridentate, respectively. The coordination of vanadium by the pyridine-2,6-dicarboxylato ligand leads to the formation of two five-membered chelate rings. [4,5]. All the hydrogen atoms of the coordinated water molecule and of the ammonium cation are involved in hydrogen bonds with the oxygen atoms from the ligands, the distances O···O or N···O ranging from 2.66 to 3.07 Å.

4-Amino- and 4-Nitrodipicolinatovanadium(V) Complexes and Their Hydroxylamido Derivatives: Synthesis, Aqueous, and Solid-State Properties

“…The [VO(dipic)(Me 2 NO)(H 2 O)] complex (shown in Figure ) crystallizes as discrete molecules without required crystallographic symmetry. Selected pertinent bond distances and angles are provided in Table along with those of other crystallographically characterized, seven-coordinate vanadium(V)-dipic complexes. − , This complex contains seven-coordinate vanadium in a pseudo, pentagonal-bipyramidal geometry. Alternatively, if one considers the hydroxylamido group to be a monodentate ligand, then the complex is a distorted, six-coordinate octahedral complex.…”