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DOI: 10.1039/A809459D (Paper) Reference Section for: J. Chem. Soc., Dalton Trans., 1999, 931-938

Structural and photophysical behaviour of lanthanide complexes with a tetraazacyclododecane featuring carbamoyl pendant arms[hair space]†

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Gaël Zucchi, Rosario Scopelliti, Pierre-André Pittet, Jean-Claude G. Bünzli and Robin D. Rogers

Abstract

The crystal and molecular structure of 1,4,7,10-tetrakis(N-benzylcarbamoylmethyl)-1,4,7,10-tetraazacyclododecane, L1, revealed an S2-symmetric molecule. One pair of pendant arms is involved in intramolecular hydrogen bonding while the other interacts with two other ligand molecules through strong intermolecular hydrogen bonds. In solution, the ligand adopts a similar geometrical arrangement at low temperature but complexes with EuIII and LuIII display an averaged C4-symmetry on the NMR timescale. One isomer only was detected, as reported for similar complexes, and the arrangement around EuIII and LuIII appears to be rigid while it is more fluxional around LaIII. Rotation of the benzyl group around the amide function was observed for EuIII and a dynamic NMR study in the range 253–333 K yielded ΔH[hair space] ‡ = 43.0 ± 0.1 kJ mol–1, ΔS[hair space] ‡ = –49.3 ± 0.4 J K–1 mol–1 and k298 = 47.7 ± 1.1 s–1. In the solid state, anhydrous eight-co-ordinate complexes were isolated and high resolution luminescence spectroscopy of EuIII in the europium and Eu-doped compounds of La, Gd and Lu confirmed a site symmetry close to C4 along the lanthanide-series. Energy transfer from the L13ππ* state to the Tb(5D4) excited state is sizable leading to an absolute quantum yield of 6.4% in MeCN, while the EuIII luminescence is only poorly sensitized, possibly because of photoinduced electron transfer processes. The Tb(5D4) and Eu(5D0) lifetimes for both solid state samples and solutions in MeCN are consistent with no water molecule in the inner co-ordination sphere but addition of water results in the ninth co-ordination site being bound to H2O: number of bound waters, q = 0.96 (Eu) and 0.71 (Tb) in MeCN + 2 M H2O and 1.19 (Eu) and 1.30 (Tb) in water. The relaxivity r1 of the gadolinium(III) complex is pH dependent and varies between 4.08 (pH 0.8), 1.88 (6.7) and 6.14 (11.1) mM–1 s–1.

References

  1. R. B. Lauffer, MRI Clinical Magnetic Resonance Imaging, eds. R. E. Edelman, M. B. Zlatkin and J. R. Hesselink, W. B. Saunders Co, Philadelphia, 1996, vol. 1, ch. 5 Search PubMed .
  2. S. Aime, M. Botta, R. S. Dickins, C. L. Maupin, D. Parker, J. P. Riehl and J. G. Williams, J. Chem. Soc., Dalton Trans., 1998, 881 RSC .
  3. G. L. DeNardo, G. R. Mirick, L. A. Kroger, R. T. O'Donnell, C. F. Meares and S. J. DeNardo, J. Nucl. Med., 1996, 37, 451 Search PubMed .
  4. L. L. Chappell, D. A. Voss, W. d. J. Horrocks and J. R. Morrow, Inorg. Chem., 1998, 37, 3989 CrossRef CAS .
  5. R. S. Dickins, T. Gunnlaugsson, D. Parker and R. D. Peacock, Chem. Commun., 1998, 1643 RSC .
  6. D. Parker, K. Senanayake and J. A. G. Williams, J. Chem. Soc., Perkin Trans. 2, 1998, 2129 RSC .
  7. J. H. Forsberg, R. M. Delaney, Q. Zhao, G. Harakas and R. Chandran, Inorg. Chem., 1995, 34, 3705 CrossRef CAS .
  8. J.-C. G. Bünzli, Lanthanide Probes in Life, Chemical and Earth Sciences. Theory and Practice, eds. J.-C. G. Bünzli and G. R. Choppin, Elsevier, Amsterdam, 1989, ch. 7, p. 219 Search PubMed .
  9. (a) A. Beeby, D. Parker and J. A. G. Williams, J. Chem. Soc., Perkin Trans. 2, 1996, 1565 RSC ; (b) R. S. Dickins, J. A. K. Howard, C. L. Maupin, J. M. Moloney, D. Parker, R. D. Peacock, J. P. Riehl and G. Siligardi, New J. Chem., 1998, 891 RSC .
  10. R. S. Dickins, J. A. K. Howard, C. W. Lehmann, J. Moloney, D. Parker and R. D. Peacock, Angew. Chem., Int. Ed. Engl., 1997, 38, 521 CrossRef .
  11. S. Aime, A. S. Batsanov, M. Botta, J. A. K. Howard, D. Parker, K. Senanayake and J. A. G. Williams, Inorg. Chem., 1994, 33, 4696 CrossRef CAS .
  12. S. Aime, M. Botta, D. Parker and J. A. G. Williams, J. Chem. Soc., Dalton Trans., 1995, 2259 RSC .
  13. (a) S. Aime, A. Barge, M. Botta, D. Parker and A. S. de Sousa, J. Am. Chem. Soc., 1997, 119, 4767 CrossRef CAS ; (b) L. Alderighi, A. Bianchi, L. Calabi, P. Dapporto, C. Giorgi, P. Losi, L. Paleari, P. Paoli, P. Rossi, B. Valtancoli and M. Virtuani, Eur. J. Inorg. Chem., 1998, 1581 CrossRef CAS .
  14. D. Parker and J. A. G. Williams, J. Chem. Soc., Perkin Trans. 2, 1995, 1305 RSC .
  15. L. J. Charbonnière, C. Balsiger, K. J. Schenk and J.-C. G. Bünzli, J. Chem. Soc., Dalton Trans., 1998, 505 RSC .
  16. M. Latva, H. Takalo, V. M. Mukkala, C. Matachescu, J.-C. Rodriguez-Ubis and J. Kankare, J. Lumin., 1997, 75, 149 CrossRef CAS .
  17. S. Aime, A. S. Batsanov, M. Botta, R. S. Dickins, S. Faulkner, C. E. Foster, A. Harrison, J. A. K. Howard, J. M. Moloney, T. J. Norman, D. Parker, L. Royle and J. A. G. Williams, J. Chem. Soc., Dalton Trans., 1997, 3623 RSC .
  18. D. Parker and J. A. G. Williams, J. Chem. Soc., Dalton Trans., 1996, 3613 RSC .
  19. S. Petoud, T. Glanzmann, J.-C. G. Bünzli, C. Piguet, Qin Xiang and R. P. Thummel, J. Lumin., 1999, in the press Search PubMed .
  20. J.-C. G. Bünzli, Lanthanide Probes in Life, Chemical and Earth Sciences. Theory and Practice, eds. J.-C. G. Bünzli and G. R. Choppin, Elsevier, Amsterdam, 1989, ch. 7, pp. 219–293 Search PubMed .
  21. F. Nicolo, D. Plancherel, G. Chapuis and J.-C. G. Bünzli, Inorg. Chem., 1988, 27, 3518 CrossRef CAS .
  22. J. R. Morrow, S. Amin, C. H. Lake and M. R. Churchill, Inorg. Chem., 1993, 32, 4566 CrossRef CAS .
  23. S. T. Frey and W. d. J. Horrocks, Inorg. Chim. Acta, 1995, 229, 383 CrossRef CAS .
  24. N. Martin, J.-C. G. Bünzli, V. McKee, C. Piguet and G. Hopfgartner, Inorg. Chem., 1998, 37, 577 CrossRef CAS .
  25. W. DeW. Horrocks, Jr. and D. R. Sudnik, Acc. Chem. Res., 1981, 14, 384 CrossRef CAS .
  26. D. D. Perrin and W. L. F. Armarego, Purification of Laboratory Chemicals, Pergamon, Oxford, 1988 Search PubMed .
  27. J.-C. G. Bünzli and F. Pilloud, Inorg. Chem., 1989, 28, 2638 CrossRef .
  28. L. J. Farrugia and T. Spek, PLATON 98 for Windows, 1998 .
  29. P. A. Pittet, D. Früh, V. Tissières and J.-C. G. Bünzli, J. Chem. Soc., Dalton Trans., 1997, 895 RSC .
  30. L. Helm, NMRICMA, version 2.03, Library of the Institute of Inorganic and Analytical Chemistry, University of Lausanne, 1998 .
  31. C. Amman, P. Meier and A. E. Merbach, J. Magn. Reson., 1982, 46, 319 CAS .
  32. J.-C. G. Bünzli and A. Milicic-Tang, Inorg. Chim. Acta, 1996, 252, 221 CrossRef .
  33. S. Petoud, J.-C. G. Bünzli, K. J. Schenk and C. Piguet, Inorg. Chem., 1997, 36, 1345 CrossRef CAS .
  34. T. Hamada, Y. Okuno, M. Ohmori, T. Niski and O. Yonemitsu, Chem. Pharm. Bull., 1981, 29, 128 CAS .
  35. G. M. Sheldrick, SADABS, Program for semiempirical absorption correction of area detector data, University of Göttingen, 1996 .
  36. G. M. Sheldrick, SHELXTL, version 5.05, Siemens Analytical X-Ray Instruments Inc., Madison, WI, 1996 .
  37. L. J. Farrugia, J. Appl. Crystallogr., 1997, 30, 565 CrossRef CAS .
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