STRUCTURE OF TWO COMPLEXES OF TETRAPHOSPHONATE CALIX[4]RESORCINARENE

Tinant, B.¹, Declercq, J-P. ¹ , Delangle, P.², Mulatier J.C. ² and Dutasta, J.P. ²

¹ Université Catholique de Louvain, unité CPMC, 1 Place Pasteur, B-1348 Louvain-la-Neuve, Belgique. Email tinant@cpmc.ucl.ac.be
² Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, F69364 Lyon Cedex07 France

Phosphorus groups are known for their great ability to complex cations. Phosphoryl groups bind hard cations like alkali or alkaline-earth metal cations, whereas thiophosphoryl groups have more affinity for soft cations like mercury or silver. Due to their high binding power, these groups have been included in more or less preorganized structures to increase the stability of the so formed complexes.[1]

The tetraphosphonate cavitand I with the four phosphoryl groups converging into the aromatic cavity (isomer iiii) has been synthetized. [2]

This ligand I represents the unique example of phosphorylated cavitands with the all i stereochemistry favorable to intra-cavity complexation. It is a strong binder for cationic species. The solid state structure of the Cs⁺ and MeNH₃⁺ complexes demonstrated the encapsulation of the guest into the aromatic cavity with participation of the four convergent PO groups.

The geometry of the two complexes is compared in details.

1. Delangle P., Dutasta, J.P., Declercq J-P. & Tinant B. (1998) Chem. Eur. J., 4, 100-106 and ref cited.
2. Delangle P., Dutasta, J.P., Mulatier J.C., Declercq J-P. & Tinant B (1998) to be published.