Journal of Cluster Science

, Volume 28, Issue 2, pp 813–823 | Cite as

Probing Crystallization Pathways in Group V Polyoxometalate Solutions

  • L. B. Fullmer
  • M. Nyman
Original Paper


Structure elucidation is extremely important to understand and control processes in synthetic chemistry, in drug design, and in biomolecular function; and the most important step of structure elucidation is crystallization. Preceding crystallization of ionic compounds is usually ion-association in solution, which can be induced by a variety of ways. Here we study ion-association of hexaniobate and hexatantalate polyoxometalate salts in mixed water-alcohol solutions. These hexametalate clusters have the unusual characteristic of increased solubility with increased ion-association, which makes them ideal candidates to understand the fundamentals of ion-pairing. We utilize direct (X-ray scattering) and indirect (ion-conductivity) methods to document the ion-association as a function of alkali, concentration, alcohol:water ratio, and Nb versus Ta. The conductivity data coupled with X-ray scattering shows that decreasing solvent polarity increases cluster-alkali association; but decreases any interaction between the alkali-cluster aggregates. Conductivity data show the trend of increasing alkali-cluster association with increasing alkali size as is expected for hexaniobate, but has some discrepancies with hexatantalate. We attribute this to the concomitant effects of protonation of the clusters, with hexaniobate being a stronger base. These studies provide insight into aqueous behaviour of these clusters that exhibit the anomalous behaviour of high solubility with maximum ion-association.


Polyoxometalate Conductivity Ion association X-ray scattering Crystallization processes 



This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under award DE-SC0010802.

Supplementary material

10876_2016_1106_MOESM1_ESM.docx (1.2 mb)
Supplementary material 1 (DOCX 1192 kb)


  1. 1.
    M. Nyman, T. M. Alam, F. Bonhomme, M. A. Rodriguez, C. S. Frazer, and M. E. Welk (2006). J. Clust. Sci. 17, 197–219.CrossRefGoogle Scholar
  2. 2.
    Y. Hou, M. Nyman, and M. A. Rodriguez (2011). Angew. Chem. 50, 12514–12517.CrossRefGoogle Scholar
  3. 3.
    I. Lindqvist (1953). Ark. Kem. 5, 247.Google Scholar
  4. 4.
    M. R. Antonio, M. Nyman, and T. M. Anderson (2009). Angew. Chem. 48, 6136–6140.CrossRefGoogle Scholar
  5. 5.
    L. B. Fullmer, P. I. Molina, M. R. Antonio, and M. Nyman (2014). Daltons Trans. 43, 15295–15299.CrossRefGoogle Scholar
  6. 6.
    D. J. Sures, S. K. Sahu, P. I. Molina, A. Navrotsky, and M. Nyman (2016). ChemistrySelect 1, 1858–1862.CrossRefGoogle Scholar
  7. 7.
    G. J.-P. Deblonde, N. Delaunay, D. Lee, A. Chagnes, G. Cote, and P. Gareil (2015). RSC Adv. 5, 64119–64124.CrossRefGoogle Scholar
  8. 8.
    P. Yin, D. Li, and T. Liu (2011). Isr. J. Chem. 51, 191–204.CrossRefGoogle Scholar
  9. 9.
    J. M. Pigga and T. Liu (2010). Inorg. Chim. Acta. 363, 4230–4233.CrossRefGoogle Scholar
  10. 10.
    G. Liu, M. L. Kistler, T. Li, A. Bhatt, and T. Liu (2006). J. Clust. Sci. 17, 427–443.CrossRefGoogle Scholar
  11. 11.
    M. Nyman and P. C. Burns (2012). Chem. Soc. Rev. 41, 7354–7367.CrossRefGoogle Scholar
  12. 12.
    T. Kojima, M. R. Antonio, and T. Ozeki (2011). J. Am. Chem. Soc. 133, 7248–7251.CrossRefGoogle Scholar
  13. 13.
    V. W. Day, W. G. Klemperer, and D. J. Maltbie (1987). J. Am. Chem. Soc. 109, 2991–3002.CrossRefGoogle Scholar
  14. 14.
    L. B. Fullmer, R. H. Mansergh, L. N. Zakharov, D. A. Keszler, and M. Nyman (2015). Cryst. Growth Des. 15, 3885–3892.CrossRefGoogle Scholar
  15. 15.
    T. M. Anderson, M. A. Rodriguez, F. Bonhomme, J. N. Bixler, T. M. Alam, and M. Nyman (2007). Daltons Trans. 9226, 4517–4522.CrossRefGoogle Scholar
  16. 16.
    J. Ilavsky and P. R. Jemian (2009). J. Appl. Crystallogr. 42, 347–353.CrossRefGoogle Scholar
  17. 17.
    N. Zhang, Z. Shen, C. Chen, G. He, and C. Hao (2015). J. Mol. Liq. 203, 90–97.CrossRefGoogle Scholar
  18. 18.
    M. K. Bera and M. R. Antonio (2016). J. Am. Chem. Soc. 138, 7282–7288.CrossRefGoogle Scholar
  19. 19.
    E. Balogh, T. M. Anderson, J. R. Rustad, M. Nyman, and W. H. Casey (2007). Inorg. Chem. 46, 7032–7039.CrossRefGoogle Scholar
  20. 20.
    J. R. Black, M. Nyman, and W. H. Casey (2006). J. Am. Chem. Soc. 68, 14712–14720.CrossRefGoogle Scholar
  21. 21.
    J. Soriano-López, S. Goberna-Ferrón, L. Vigara, J. J. Carbó, J. M. Poblet, and J. R. Galán-Mascarós (2013). Inorg. Chem. 52, 4753–4755.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Department of ChemistryOregon State UniversityCorvallisUSA

Personalised recommendations