Structure and dynamics of all of the stereoisomers of europium complexes of tetra(carboxyethyl) derivatives of dota: ring inversion is decoupled from cooperative arm rotation in the RRRR and RRRS isomers

Abstract

The absolute configuration of the four stereoisomeric α-substituted derivatives of dota has been defined; in their Eu complexes, 2D-NMR methods have revealed that in solution ring inversion is independent of pendant arm rotation and the (RRRR)-[EuL^1a] complex which in the solid state crystallises as a square antiprismatic structure.

References

1. D. Parker and J. A. G. Williams, J. Chem. Soc., Dalton Trans., 1996, 3613.
2. D. Parker, in Comprehensive Supramolecular Chemistry, ed. D. N. Reinhoudt, J. E. Atwood, F. Vogtle, D. D. MacNicol and J.-M. Lehn, Pergamon, Oxford, 1996, vol. 10. ch. 17.
3. S. Aime, M. Botta, M. Fasano and E. Terreno, Chem. Soc. Rev., 1998, 27, 19; K. Kumar and M. F. Tweedle, Pure Appl. Chem., 1993, 65, 515; J. A. Peters, J. Huskens and D. J. Raber, Prog. NMR Spectrosc., 1996, 28, 283.
4. D. Parker, K. Senanayake and J. A. G. Williams, Chem. Commun., 1997, 1777; D. Parker and J. A. G. Williams, Chem. Commun., 1998, 245; D. Parker and T. Gunnlaugsson, Chem. Commun., 1998, 511; D. Parker and J. A. G. Williams, J. Chem. Soc., Perkin Trans. 2, 1998, in press.
5. (a) S. Amin, J. R. Morrow, C. H. Lake and M. R. Churchill, Angew. Chem., Int. Ed. Engl., 1994, 33, 773; (b) M. Spirlet, J. Rebizant, J. F. Desreux and M.-F. Loncin, Inorg. Chem., 1984, 23, 359.
6. R. S. Dickins, J. A. K. Howard, C. W. Lehmann, J. M. Moloney, D. Parker and R. D. Peacock, Angew. Chem., Int. Ed. Engl., 1997, 36, 521.
7. S. Aime, M. Botta, M. Fasano, M. P. M. Harques, C. F. G. C. Geraldes, D. Pubanz and A. E. Merbach, Inorg. Chem., 1997, 36, 2059 and references therein.
8. S. Hoeft and K. Roth, Chem. Ber., 1993, 126, 869; V. Jacques and J. F. Desreux, Inorg. Chem., 1994, 33, 4048.
9. S. Aime, M. Botta and G. Ermondi, Inorg. Chem., 1992, 31, 4291.