Racemisation behaviour of trinuclear helicates formed from ethylene-bridged tris(catechol) ligands and titanium(IV) ions

Abstract

Trinuclear helicates are self-assembled from ligand H₆L¹ and Ti^IV ions in the presence of sodium or potassium carbonate and they racemise by consecutive inversion of the three complex units.

References

1. B. Kersting, M. Meyer, R. E. Powers and K. N. Raymond, J. Am. Chem. Soc., 1996, 118, 7221.
2. M. Albrecht, M. Schneider and H. Röttele, Chem. Ber./Recueil, 1997, 130, 615.
3. L. J. Charbonnière, A. F. Williams, U. Frey, A. E. Merbach, P. Kamalyprija and O. Schaad, J. Am. Chem. Soc., 1997, 119, 2488.
4. For examples of dinuclear oxygen-donor helicates, see: R. C. Scarrow, D. L. White and K. N. Raymond, J. Am. Chem. Soc., 1985, 107, 6540; E. J. Enemark and T. D. P. Stack, Angew. Chem., Int. Ed. Engl., 1995, 34, 996; M. Albrecht and S. Kotila, Angew. Chem., Int. Ed. Engl., 1996, 35, 1208.
5. Reviews: E. C. Constable, Prog. Inorg. Chem., 1994, 42, 67; A. F. Williams, Chem. Eur. J., 1997, 3, 15.
6. M. Albrecht, H. Röttele and P. Burger, Chem. Eur. J., 1996, 2, 1264.
7. M. Albrecht and C. Riether, Chem. Ber., 1996, 129, 829.