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DOI: 10.1039/A906108H (Paper) Reference Section for: Phys. Chem. Chem. Phys., 1999, 1, 5215-5221

FTIR and EXAFS investigations of microstructures of gold solvent extraction: hydrogen bonding between modifier and Au(CN)2-

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Gang Ma, Wenfei Yan, Tiandou Hu, Jing Chen, Chunhua Yan, Hongcheng Gao, Jinguang Wu and Guangxian Xu

Abstract

The microstructures of loaded organic phases of three quaternary amine solvent extraction systems for gold, which were N263–xylene, N263–tributyl phosphate (TBP)–dodecane and N263–2-ethylhexanol (isooctanol)–dodecane (N263-trialkylmethylammonium chloride; alkyl=C8–C10), were studied by Fourier transform infrared (FTIR) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy. According to the EXAFS results, it was found that the gold coordination environment was the same before and after extraction. However, the C3N stretching vibrations of Au(CN)2- in the three systems differed greatly. The second derivative spectra of C3N stretching bands of Au(CN)2- were also found to be different. In order to explain the differences in the IR characteristics of C3N in the three extraction systems, three microstructure models are proposed. For the N263–xylene system, the model is a simple ion pair. For the other two systems with a modifier (TBP and isooctanol), the models are two supramolecular structures based on hydrogen bonding between the modifier and Au(CN)2-. Some related work such as on the hydration of acetonitrile and the fine structure of C3N in solid KAu(CN)2 was also performed in order to offer additional supporting evidence for the reliability of the proposed models.

References

  1. J. D. Miller and M. B. Mooiman, Sep. Sci. Technol., 1984-85, 19, 895 Search PubMed.
  2. T. Groenewald, in Proceedings of the International Solvent Extraction Conference (ISEC'74), ed. G. V. Jeffreys, Society of Chemistry Industry, London, 1974, vol. 3, p. 2715 Search PubMed.
  3. M. B. Mooiman, J. D. Miller and M. M. Mena, in Proceedings of the International Solvent Extraction Conference (ISEC'83), American Institute of Chemical Engineers, Denver, CO, 1983, p. 530 Search PubMed.
  4. M. B. Mooiman and J. D. Miller, Hydrometallurgy, 1986, 16, 245 CAS.
  5. P. A. Riveros, Hydrometallurgy, 1990, 24, 135 CrossRef CAS.
  6. F. J. Alguacil, A. Hernandez and A. Luis, Hydrometallurgy, 1990, 24, 157 CAS.
  7. C. Caravaca, F. J. Alguacil, A. Sastre and M. Martinez, Hydrometallurgy, 1996, 40, 89 CrossRef CAS.
  8. T. K. Jain, M. Varshney and A. Maitra, J. Phys. Chem., 1989, 93, 7409 CrossRef CAS.
  9. D. J. Christopher, J. Yarwood, P. S. Belton and B. P. Hills, J. Colloid Interface Sci., 1992, 152, 465 CrossRef CAS.
  10. Z. H. Xu, S. F. Weng, H. Guo, J. G. Wu and G. X. Xu, Acta Sci. Nat. Univ. Pekin., 1983, 19(1), 45 Search PubMed.
  11. J. G. Wu, N. Shi, H. C. Gao, D. Chen, H. Guo, S. F. Weng and G. X. Xu, Sci. Sin., Ser. B, 1984, 27, 249 Search PubMed.
  12. J. G. Wu, H. C. Gao, T. Z. Jin, D. Chen, N. Shi, X. X. Liang and G. X. Xu, Acta Sci. Nat. Univ. Pekin., 1985, 21(4), 1 Search PubMed.
  13. R. D. Neuman, N. F. Zhou, J. G. Wu, M. A. Jones, A. G. Gaonkar, S. J. Park and M. L. Agraw, Sep. Sci. Technol., 1990, 25, 1655 CAS.
  14. N. F. Zhou, J. G. Wu, Z. J. Yu, R. D. Neuman, D. J. Wang and G. X. Xu, Sci. China, Ser. B, 1997, 40, 61 Search PubMed.
  15. Y. H. Shen, D. J. Wang and J. G. Wu, Chin. Sci. Bull., 1997, 42, 1168 Search PubMed.
  16. A. Rosenzweig and D. T. Cromer, Acta Crystallogr., 1959, 12, 709 CrossRef CAS.
  17. D. F. Evans, D. Jones and G. Wilkinson, J. Chem. Soc., 1964, 3164 RSC.
  18. D. Jones and D. F. Evans, Nature (London), 1963, 199, 277 CAS.
  19. A. Allerhand and R. von R. Schleyer, J. Am. Chem. Soc., 1963, 85, 866 CrossRef CAS.
  20. D. F. Shriver, J. Am. Chem. Soc., 1963, 85, 1405 CrossRef CAS.
  21. J. S. Loring and W. R. Fawcett, J. Phys. Chem. A, 1999, 103, 3608 CrossRef CAS.
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