Clays and Clay Minerals

, Volume 23, Issue 2, pp 103–107 | Cite as

Perturbation of Structural Fe3+ in Smectites by Exchange Ions

  • M. B. McBride
  • T. J. Pinnavaia
  • M. M. Mortland


The electron spin resonance of some structural Fe3+ for montmorillonites having low Fe3+ content, is perturbed by electrostatic interaction between exchange cations and structural charge sites. The position of charge centers of organic and inorganic cations in the interlayer can thus be determined at various levels of solvation. Dielectric media between the silicate layers lower the electrostatic attraction between the silicate and the exchange cations. The silicate charge appears to be partially delocalized on structural oxygen atoms as shown by electron spin resonance and i.r. spectroscopy. There is also evidence that divalent exchange cations on dehydrated montmorillonites cause hydrolysis of water; the protons so produced migrate to structural charge sites.


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  1. Angel, B. R. and Hall, P. L. (1972) Electron spin resonance studies of kaolins: Proc. Int. Clay Conf. Madrid, pp. 47–60.Google Scholar
  2. Farmer, V. C. and Russell, J. D. (1971) Interlayer complexes in layer silicates; the structure of water in lamellar ionic solutions: Trans. Faraday Soc. 67, 2737–2749.CrossRefGoogle Scholar
  3. Gast, R. G. and Mortland, M. M. (1971) Self-diffusion of alkylammonium ions in montmorillonite: J. Colloid Interface Sci. 37, 80–92.CrossRefGoogle Scholar
  4. Grim, R. E. (1968) Clay Mineralogy, 2nd Edition. McGraw-Hill, New York. pp. 220–223.Google Scholar
  5. Grim, R. E. (1968) Clay Mineralogy, 2nd Edition. McGraw-Hill, New York. p. 260.Google Scholar
  6. Kemp, R. C. (1971) Orthorhombic iron centres in musco-vite and phlogopite micas: J. Phys. C. 4, L11–L13.CrossRefGoogle Scholar
  7. Levanon, H. and Luz, Z. (1968) ESR and NMR of Mn (II) complexes in methanol: J. Chem. Phys. 49, 2031–2040.CrossRefGoogle Scholar
  8. McBride, M. B. and Mortland, M. M. (1974) Cu (II) interactions with montmorillonite: evidence from physical methods: Soil Sci. Soc. Am. Proc. 38, 408–415.CrossRefGoogle Scholar
  9. McBride, M. B., Mortland, M. M. and Pinnavaia, T. J. (1975) Exchange ion positions in smectite: effects on electron spin resonance of structural iron: Clays and Clay Minerals 23, 162.CrossRefGoogle Scholar
  10. Mortland, M. M. (1966) Urea complexes with montmorillonite: an i.r. absorption study: Clay Minerals 6, 143–156.CrossRefGoogle Scholar
  11. Mortland, M. M. and Raman, K. V. (1968) Surface acidity of smectites in relation to hydration, exchangeable cation, and structure: Clays and Clay Minerals 16, 393–398.CrossRefGoogle Scholar
  12. Ross, G. J. and Mortland, M. M. (1966) A soil beidellite: Soil Sci. Soc. Am. Proc. 30, 337–343.CrossRefGoogle Scholar
  13. Russell, J. D. and Farmer, V. C. (1964) I.r. spectroscopic study of the dehydration of montmorillonite and saponite: Clay Min. Bull. 5, 443–464.CrossRefGoogle Scholar
  14. Russell, J. D. and Fraser, A. R. (1971) I.r. spectroscopic evidence for interaction between hydronium ions and lattice OH groups in montmorillonite: Clays and Clay Minerals 19, 55–59.CrossRefGoogle Scholar
  15. Shainberg, I. and Kemper, W. D. (1966) Hydration status of adsorbed cations: Soil Sci. Am. Proc. 30, 707–713.CrossRefGoogle Scholar
  16. Walker, G. F. (1955) The mechanism of dehydration of Mg-vermiculite: Clays and Clay Minerals, 4th Nat. Conf. pp. 101–115.Google Scholar
  17. Yariv, S. and Heller-Kallai, L. (1973) I.r. evidence for migration of protons in H and organo-montmoril-lonites: Clays and Clay Minerals 21, 199–200.CrossRefGoogle Scholar

Copyright information

© The Clay Minerals Society 1975

Authors and Affiliations

  • M. B. McBride
    • 1
  • T. J. Pinnavaia
    • 1
  • M. M. Mortland
    • 1
  1. 1.Contribution from the Departments of Crop and Soil Sciences, Geology and ChemistryMichigan State UniversityEast LansingUSA

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