View PDF Version
 
DOI: 10.1039/A707126D (Paper) Reference Section for: J. Chem. Soc., Dalton Trans., 1998, 981-990

Vibrational modes and structure of liquid and gaseous zirconium tetrachloride and of molten ZrCl4–CsCl mixtures[hair space]‡

(Note: The full text of this document is currently only available in the PDF Version )

G. M. Photiadis and G. N. Papatheodorou

Abstract

Raman spectra of liquid and gaseous zirconium tetrachloride and of molten ZrCl4–CsCl mixtures have been measured. Changes of the relative Raman intensities in the vapor phase, near and above the critical point, have established the dimerization reaction 2ZrCl4(g) ⇄ Zr2Cl8(g), ΔHR = –56.6 ± 1.1 kJ mol–1. Spectra of solid and molten zirconium chloride show that in the liquid phase ZrCl4 monomers are present in equilibrium with polymer-like (ZrCl4)n species. A systematic investigation of the Raman spectra of the solid mixtures formed upon cooling the ZrCl4–CsCl melts at different compositions has shown that apart from the known Cs2ZrCl6 a new compound with stoichiometry CsZr2Cl9 is also formed. The spectra of solid and molten Cs2ZrCl6 and CsZr2Cl9 show that ZrCl62– and the Zr2Cl9– are present in both phases. In molten ZrCl4–CsCl mixtures and at compositions xZrCl4 < 0.33 the ZrCl62– octahedra are predominant. In the range 0.33 < xZrCl4 < 0.66 the spectral changes with temperature and composition reflect an equilibrium involving three ionic species: ZrCl62–, Zr2Cl9– and Zr2Cl102– (or ZrCl5–). At mole fractions rich in ZrCl4 (xZrCl4 > 0.66) the spectra indicate an equilibrium between the ionic Zr2Cl9–, the ZrCl4 monomer and the (ZrCl4)n polymer-like species. All data suggest that the value of n is small and most probably hexamers and/or dimers are the predominant ‘polymer’ species in these melts.

References

  1. M. Brooker and G. N. Papatheodorou, Adv. Molten Salt Chem., 1983, 5, 27 Search PubMed.
  2. E. A. Pavlatou and G. N. Papatheodorou, Proc. 8th Int. Symp. Molten Salts, 1992, 92-16, 72 Search PubMed.
  3. G. A. Voyiatzis and G. N. Papatheodorou, Ber. Bunsenges. Phys. Chem., 1994, 98, 683.
  4. G. N. Papatheodorou, J. Chem. Phys., 1977, 66, 2893 CrossRef CAS.
  5. G. M. Photiadis, G. A. Voyiatzis and G. N. Papatheodorou, Molten Salt Forum, Trans. Tech. Publications Ltd. Aedermanusdorf, Switzerland, 1993, vols. 1 and 2, pp. 183–194 Search PubMed.
  6. L. M. Toth, A. S. Quist and G. E. Boyd, J. Phys. Chem., 1973, 77, 1384 CrossRef CAS.
  7. G. J. Kipouros, J. H. Flint and D. R. Sadoway, Inorg. Chem., 1985, 24, 3881 CrossRef CAS.
  8. B. Krebs, Z. Anorg. Allg. Chem., 1970, 378, 263 CrossRef CAS; Angew. Chem., 1969, 81, 120 Search PubMed; Angew. Chem., Int. Ed. Engl., 1969, 8, 146 Search PubMed.
  9. A. B. Salyulev and I. D. Kornyakova, Rasplavy, 1991, 6, 95 Search PubMed.
  10. W. Brockner and A. F. Demiray, J. Raman Spectrosc., 1978, 7, 330.
  11. A. B. Salyulev and I. D. Kornyakova, Rasplavy, 1994, 2, 60 Search PubMed; 1995, 6, 58.
  12. G. J. Kipouros and S. N. Flengas, J. Electrochem. Soc., 1985, 132, 1087 CAS.
  13. G. J. Kipouros and S. N. Flengas, Proc. 7th Int. Symp. Molten Salts, 1990, 90-17, 626 Search PubMed.
  14. W. J. Kroll, J. Less-Common Met., 1965, 7, 361 Search PubMed.
  15. S. Boghosian and G. N. Papatheodorou, J. Phys. Chem., 1989, 93, 415 CrossRef CAS.
  16. H. Schafer and M. Binnewies, Z. Anorg. Allg. Chem., 1974, 410, 251 CrossRef.
  17. R. C. Taylor, E. M. Larsen and D. R. Taylor, J. Inorg. Nucl. Chem., 1981, 43, 293 CrossRef CAS.
  18. R. J. H. Clark, B. K. Hunter and D. M. Rippon, Inorg. Chem., 1972, 11, 56 CrossRef CAS.
  19. N. D. Denisova, E. K. Safronov and O. N. Bystrova, Russ. J. Inorg. Chem. (Engl. Transl.), 1966, 11, 171.
  20. L. A. Nisel'son and T. D. Sokolova, Russ. J. Inorg. Chem. (Engl. Transl.), 1962, 7, 1382.
  21. L. A. Nisel'son, V. I. Stolyarov and T. D. Sokolova, Russ. J. Phys. Chem. (Engl. Transl.), 1965, 39, 1614 Search PubMed.
  22. I. S. Morozov and S. In-Chzhu, Zh. Neorg. Khim., 1959, 4, 680 Search PubMed.
  23. D. A. Asvestas, P. Pint and S. N. Flengas, Can. J. Chem., 1977, 55, 1154 CAS.
  24. Phase Diagrams for Ceramists, compiled at the National Institute of Standards and Technology, edited and published by the American Ceramic Society, Westerville, OH Search PubMed.
  25. H. D. B. Jenkins and K. F. Pratt, Adv. Inorg. Chem. Radiochem., 1979, 22, 1 Search PubMed.
  26. W. V. Bronswyk, R. J. H. Clark and L. Maresca, Inorg. Chem., 1969, 8, 1395 CrossRef.
  27. G. N. Papatheodorou, Inorg. Nucl. Chem. Lett., 1975, 11, 483 Search PubMed.
  28. K. Nakamoto, Infrared and Raman Spectra of Inorganic and Coordination Compounds, 4th edn., Wiley, New York, 1986 Search PubMed.
  29. R. E. Hester, in Raman Spectroscopy Theory and Practice, ed. H. A. Szymanski, Plenum Press, New York, 1967 Search PubMed.
  30. L. A. Woodward and M. J. Ware, Spectrochim. Acta, Part A, 1963, 19, 775 CrossRef CAS.
  31. B. Boressen, V. Dracoupoulos, G. Photiadis, B. Gilbert and G. N. Papatheodorou, Proc. 10th Int. Symp. Molten Salts, 1996, 96-7, 11 Search PubMed.
  32. V. Dracopoulos, B. Gilbert, B. Boressen, G. Photiadis and G. N. Papatheodorou, J. Chem. Soc., Faraday Trans., 1997, 3081 RSC.
  33. C. S. Creaser and J. A. Creighton, J. Chem. Soc., Dalton Trans., 1975, 1402 RSC.
  34. A. F. Demiray and W. Brockner, Spectrochim. Acta, Part A, 1979, 35, 659 CrossRef.
  35. A. F. Demiray, W. Brockner, B. N. Cyvin and S. J. Cyvin, Z. Naturforsch., Teil A, 1979, 34, 362.
  36. J. D. Black, J. T. R. Dunsmuir, I. W. Forrest and A. P. Lane, Inorg. Chem., 1975, 14, 1257 CrossRef CAS.
  37. R. Saillant, R. B. Jackson, W. E. Streib, K. Folting and R. A. D. Wentworth, Inorg. Chem., 1971, 10, 1453 CrossRef.
  38. I. R. Beattie, T. R. Gilson and G. A. Ozin, J. Chem. Soc. A, 1968, 2765 RSC.
  39. J. Beck, Chem. Ber., 1991, 124, 677 CAS.
  40. L. Chen and F. A. Cotton, Inorg. Chem., 1996, 35, 7364 CrossRef CAS.
  41. R. J. Ziegler and W. M. Risen, jun., Inorg. Chem., 1972, 11, 2796 CrossRef.
  42. M. M. Metallinou, L. Nalbandian, G. N. Papatheodorou, W. Voight and H. H. Emons, Inorg. Chem., 1991, 30, 4260 CrossRef CAS.
  43. J. I. Bullock, F. W. Parret and N. J. Taylor, Can. J. Chem., 1974, 52, 2880 CAS.
  44. T. J. Kistenmacher and G. D. Stucky, Inorg. Chem., 1971, 10, 122 CrossRef.
  45. J. Eicher, U. Muller and K. Dehnicke, Z. Anorg. Allg. Chem., 1985, 521, 37 CrossRef CAS.
  46. C. S. Creaser and J. A. Creighton, J. Inorg. Nucl. Chem., 1979, 41, 469 CrossRef CAS.
  47. T. G. Hughes, C. Meredith and J. SutcliVe, Inorg. Chim. Acta, 1988, 143, 209 CrossRef CAS.
  48. F. Esmadi and H. SutcliVe, Indian J. Chem., Sect. A, 1991, 30, 99.
  49. A. F. Demiray and W. Brockner, Monatsh. Chem., 1980, 111, 21 CAS.
  50. J. Zhang and J. D. Corbett, Inorg. Chem., 1995, 34, 1652 CrossRef CAS.
Click here to see how this site uses Cookies. View our privacy policy here.