Search for content and authors

Nonaqueous approach to a metal-organic framework: A new vanadium-oxobenzoate as case study

Igor Djerdj 1Minhua Cao 2,3Radovan Cerny 4Zvonko Jagličič 5,6Fabia Gozzo 7Markus Antonietti 2Markus Niederberger 1

1. ETH Zürich (ETHZ), Wolfgang-Pauli-Strasse 10, Zürich 8093, Switzerland
2. Max Planck Institute of Colloids and Interfaces (MPIKGF), Research Campus Golm, Potsdam 14424, Germany
3. Department of Chemistry, Northeast Normal University, Changchun 13324, China
4. University of Geneva, 24 quai Ernest-Ansermet, Geneva 1211, Switzerland
5. Institute of mathematics physics and mechanics (IMFM), Jadranska 19, Ljubljana 1000, Slovenia
6. Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jamova 2, Ljubljana 1000, Slovenia
7. Swiss Light Source, Paul Scherrer Institute, Villigen PSI 5232, Switzerland


Metal–organic frameworks (MOFs) based on transition metal elements are an important family of materials as they provide an opportunity to correlate their structure and magnetism, in addition to their adsorption and related properties arising from the porous structure. Among the broad family of transition metals, vanadium is particularly challenging due to its appearance in different oxidation states ranging from 2+ to 5+, which consequently exhibits an exceptionally rich variety of electronic ground states and magnetic properties. A new vanadium oxobenzoate [VO(C6H5COO)2] has been synthesized under solvothermal conditions by reacting VO(OiPr)3, benzoic acid and toluene. The resulting powder was thoroughly investigated by a number of complementary methods like XPS, electron microscopy techniques, synchrotron X-ray powder diffraction, thermal analysis, bulk density, and magnetic DC susceptibility measurement. The compound crystallizes in the monoclinic system with a = 20.661(2), b = 6.791(1), c = 9.959(1) Å, b = 92.08°, space group C2, and Z = 4. The crystal structure has been solved from synchrotron X-ray powder diffraction data using a direct space global optimization technique (program FOX) and refined by the constrained Rietveld method. The V atoms are in 4+ oxidation state as revealed by XPS. In the complex they have 5-fold coordination with respect to the oxygens, with the metal cation center in distorted squared pyramid coordination. Vanadium atoms are mutually linked via oxygen atoms forming helical zig-zag chains along the crystal b-axis as illustrated in Figure 1. The VO5 inorganic layers lie at the distance of 10 Å, and are separated from each other by the organic part composed of benzoate moieties.


Figure 1. Molecular packing of vanadium oxobenzoate viewed along the [001] direction. The projection of unit cell is marked as a gray rectangle.


Legal notice
  • Legal notice:

Related papers

Presentation: Poster at 11th European Powder Diffraction Conference, Poster session, by Igor Djerdj
See On-line Journal of 11th European Powder Diffraction Conference

Submitted: 2008-04-22 17:56
Revised:   2009-06-07 00:48