Non-classical FeII spin-crossover behaviour in polymeric iron(II) compounds of formula [Fe(NH2trz)3]X2xH2O (NH2trz=4-amino-1,2,4-triazole; X=derivatives of naphthalene sulfonate)

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

Petra J. van Koningsbruggen, Yann Garcia, Epiphane Codjovi, René Lapouyade, Olivier Kahn, Leopold Fournès and Louis Rabardel


Abstract

A new series of iron(ii) spin-crossover materials of formula [Fe(NH2trz)3 ]X2xH2O [X=1-naphthalene sulfonate (1ns), 2-naphthalene sulfonate (2ns), 4-hydroxy-1-naphthalene sulfonate (4OH-1ns), 4-amino-1-naphthalene sulfonate (4NH2-1ns) and 6-hydroxy-2-naphthalene sulfonate (6OH-2ns)] are reported. The structure of these compounds consists of linear chains in which the Fe(ii) ions are linked by triple N1 ,N2-1,2,4-triazole bridges. All compounds show non-classical spin-crossover behaviour. Optical and magnetic measurements recorded upon heating show an abrupt low-spin to high-spin transition accompanied by a pronounced thermochromic effect occuring between 330 and 340 K depending on the anion. Thermogravimetric analyses show that the transition is induced by the removal of the two lattice water molecules, which initially stabilized the low-spin state. The dynamical character of this transition has been monitored by extended 57Fe Mössbauer spectroscopic studies on [Fe(NH2trz)3 ](2ns)2xH2O. Upon cooling, the dehydrated modifications show classical spin-crossover behaviour with hysteresis at much lower temperatures, ranging from 229 to 297 K depending on the anion. [Fe(NH2trz)3 ](2ns)2 represents one of the first iron(ii) spin-crossover materials showing a spin transition in the close vicinity of room temperature (290 K) accompanied by hysteresis (14 K).


References

  1. P. Gütlich, Struct. Bonding (Berlin), 1981, 44, 83.
  2. J. Zarembowitch and O. Kahn, New J. Chem., 1991, 15, 181 Search PubMed.
  3. P. Gütlich, in Mössbauer Spectroscopy Applied to Inorganic Chemistry, ed. G. J. Long, Modern Inorganic Chemistry Series, Plenum Press, New York, 1984, vol. 1 Search PubMed.
  4. E. König, Prog. Inorg. Chem., 1987, 35, 527.
  5. P. Gütlich and A. Hauser, Coord. Chem. Rev., 1990, 97, 1 CrossRef.
  6. P. Gütlich, A. Hauser and H. Spiering, Angew. Chem., Int. Ed. Engl., 1994, 33, 2024 CrossRef.
  7. O. Kahn and E. Codjovi, Philos. Trans. R. Soc. London A, 1996, 354, 359 Search PubMed.
  8. O. Kahn, Molecular Magnetism, VCH, New York, 1993 Search PubMed.
  9. O. Kahn, E. Codjovi, Y. Garcia, P. J. van Koningsbruggen, R. Lapouyade and L. Sommier, in Molecule-Based Magnetic Materials, ed. M. M. Turnbull, T. Sugimoto and L. K. Thompson, Symp. Ser. No. 644, ACS, Washington, DC, 1996, p. 298 Search PubMed.
  10. J. G. Haasnoot, in Magnetism: A Supramolecular Function, ed. O. Kahn, Kluwer Academic, Dordrecht, Netherlands, 1996, p. 299 Search PubMed.
  11. O. Kahn, J. Kröber and C. Jay, Adv. Mater., 1992, 4, 718 CrossRef CAS.
  12. C. Jay, F. Grolière, O. Kahn and J. Kröber, Mol. Cryst. Liq. Cryst., 1993, 234, 255 Search PubMed.
  13. J. Kröber, J.-P. Audière, R. Claude, E. Codjovi, O. Kahn, J. G. Haasnoot, F. Grolière, C. Jay, A. Bousseksou, J. Linarès, F. Varret and A. Gonthier-Vassal, Chem. Mater., 1994, 6, 1404 CrossRef.
  14. J. Kröber, E. Codjovi, O. Kahn, F. Grolière and C. Jay, J. Am. Chem. Soc., 1993, 115, 9810 CrossRef CAS.
  15. L. G. Lavrenova, V. N. Ikorskii, V. A. Varnek, I. M. Oglezneva and S. V. Larionov, J. Struct. Chem., 1993, 34, 960 CrossRef.
  16. L. G. Lavrenova, V. N. Ikorskii, V. A. Varnek, I. M. Oglezneva and S. V. Larionov, Koord. Khim., 1986, 12, 207 Search PubMed.
  17. V. A. Varnek and L. G. Lavrenova, J. Struct. Chem., 1994, 35, 842.
  18. L. G. Lavrenova, V. N. Ikorskii, V. A. Varnek, I. M. Oglezneva and S. V. Larionov, Koord. Khim., 1990, 16, 654 Search PubMed.
  19. L. G. Lavrenova, N. G. Yudina, V. N. Ikorskii, V. A. Varnek, I. M. Oglezneva and S. V. Larionov, Polyhedron, 1995, 14, 1333 CrossRef CAS.
  20. R. Bronisz, K. Drabent, P. Polomka and M. F. Rudolf, ICAME95, Conference Proceedings, 1996, 50, 11 Search PubMed.
  21. E. Codjovi, L. Sommier, O. Kahn and C. Jay, New J. Chem., 1996, 20, 503 Search PubMed.
  22. V. P. Sinditskii, V. I. Sokol, A. E. Fogel'zang, M. D. Dutov, V. V. Serushkin, M. A. Porai-Koshits and B. S. Svetlov, Russ. J. Inorg. Chem., 1987, 32, 1149.
  23. A. Michalowicz, J. Moscovici, B. Ducourant, D. Cracco and O. Kahn, Chem. Mater., 1995, 7, 1833 CrossRef CAS.
  24. N. V. Bausk, S. B. Érenburg, L. N. Mazalov, L. G. Lavrenova and V. N. Ikorskii, J. Struct. Chem., 1994, 35, 509.
  25. N. V. Bausk, S. B. Érenburg, L. G. Lavrenova and L. N. Mazalov, J. Struct. Chem., 1995, 36, 925.
  26. S. B. Érenburg, N. V. Bausk, V. A. Varnek and L. G. Lavrenova, J. Magn. Magn. Mater., 1996, 157/158, 595 CrossRef.
  27. V. A. Varnek and L. G. Lavrenova, J. Struct. Chem., 1995, 36, 104.
  28. V. Ksenofontov and P. Gütlich, personal communication, 1995.
  29. Y. Garcia, P. J. van Koningsbruggen, E. Codjovi, R. Lapouyade, O. Kahn and L. Rabardel, J. Mater. Chem., 1997, 7, 857 RSC.
  30. Y. Garcia, P. J. van Koningsbruggen, G. Bravic, P. Guionneau, D. Chasseau, G. L. Cascarano, J. Moscovici, K. Lambert, A. Michalowicz and O. Kahn, Inorg. Chem., submitted Search PubMed.
  31. F. Grandjean, G. J. Long, B. B. Hutchinson, L. Ohlhausen, P. Neill and J. D. Holcomb, Inorg. Chem., 1989, 28, 4406 CrossRef CAS.
  32. K. H. Sugiyarto, D. C. Graig, A. D. Rae and H. A. Goodwin, Aust. J. Chem., 1994, 47, 869 CAS.
  33. K. H. Sugiyarto and H. A. Goodwin, Aust. J. Chem., 1988, 41, 1645 CAS.
  34. M. Sorai, J. Ensling, K. M. Hasselbach and P. Gütlich, Chem. Phys., 1977, 20, 197 CrossRef CAS.
  35. T. Buchen, P. Gütlich, K. H. Sugiyarto and H. A. Goodwin, Chem. Eur. J., 1996, 2, 1134 CrossRef CAS.
  36. Y. Garcia, P. J. van Koningsbruggen, E. Codjovi, R. Lapouyade and O. Kahn, in preparation.
  37. J. Kolnaar and J. G. Haasnoot, personal communication, 1996.