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DOI: 10.1039/A702041D (Paper) Reference Section for: J. Chem. Soc., Perkin Trans. 2, 1997, 1985-1990

Metamorphosis of caffeine hydrate and anhydrous caffeine

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Howell G. M. Edwards, Emma Lawson, Marcel de Matas, Len Shields and Peter York

Abstract

The phase stability, interconversion and physicochemical characterisation of caffeine (1,3,7-trimethylpurine-2,6-dione) hydrate and anhydrous caffeine relate to the strength of the available hydrogen-bonds. A hydrogen-bonded T-branched spine of hydrate molecules establishes a weak lattice bond for the caffeine hydrate which, under ambient conditions, transforms to a β-anhydrous phase which in turn, at 155 °C and with an enthalpy of 3.6 kJ mol–1, converts to a trigonal phase α-anhydrous caffeine. The anhydrous phases are stabilised by weak CH3 to CO hydrogen bonds.

References

  1. S. R. Byrn, Solid State Chemistry of Drugs, Academic Press, London, 1982 Search PubMed.
  2. D. J. Sutor, Acta Crystallogr., (a) 1958, 11, 83; (b) 1958, 11, 453 Search PubMed.
  3. M. Parvez and C. Ferguson, Acta Crystallogr., Sect. C, 1994, 50, 1303 CrossRef.
  4. R. Gerdil and R. E. Marsh, Acta Crystallogr., 1960, 13, 166 CrossRef CAS.
  5. P. R. Perrier and S. R. Byrn, J. Org. Chem., 1982, 47, 4671 CrossRef CAS.
  6. G. M. Sheldrick, 1993, University of Göttingen, 3400 Göttingen, Germany.
  7. R. K. Khankari, D. Law and D. J. W. Grant, Int. J. Pharm., 1992, 82, 117 CrossRef CAS.
  8. J. H. Sharp, G. W. Brindley and B. N. N. Achar, J. Am. Chem. Soc., 1966, 49, 379 CAS.
  9. U. J. Griesser and A. Burger, Int. J. Pharm., 1995, 120, 83 CrossRef CAS.
  10. M. Majoube, M. Henry and G. Vergoten, J. Raman Spectrosc., 1994, 25, 233 CAS.
  11. M. Majoube, Ph. Millie, L. Chinsky, P. Y. Turpin and G. Vergoten, J. Mol. Struct., 1995, 355, 147 CrossRef CAS.
  12. J. Sadlej, J. Mol. Struct., 1992, 274, 247 CrossRef CAS.
  13. J. E. Lancaster and N. B. Colthup, J. Chem. Phys., 1954, 22, 1149 CAS.
  14. S. J. Daunt, H. F. Shurvell and L. Pazdernik, J. Raman Spectrosc., 1975, 4, 205 CAS.
  15. A. Navarro, J. J. Lopez Gonzalez, M. Fernandez Gomez, F. Marquez and J. C. Otero, J. Mol. Struct., 1996, 376, 353 CrossRef CAS.
  16. A. M. Heyns and M. W. Venter, J. Chem. Phys., 1990, 93(11), 7581 CrossRef CAS.
  17. H. Rasmussen and E. Sletten, Acta Chem. Scand., 1973, 27, 2757 CAS.
  18. E. Shefter, J. Pharm. Sci., 1968, 57(7), 1163 CAS.
  19. D. J. Sutor, J. Chem. Soc., 1963, 1105 RSC.
  20. S. Krimm, Science, 1967, 158, 530.
  21. W. J. Dulmage and W. N. Lipscomb, Acta Crystallogr., 1951, 4, 330 CrossRef CAS.
  22. M. W. Dougill and G. A. Jeffrey, Acta Crystallogr., 1953, 6, 831 CrossRef CAS.