Fullerene Ylidene Malonate Supramolecular Triads

This paper describes the synthesis and characterization of novel covalently bound fullerene ylidene malonate dyads in which the linker between the two units is a di-, tri-, or tetraethylene glycol unit. The synthesis involves a stepwise, convergent addition of the two components to bis(malonate crown ethers) of increasing overall dimensions through (i) Knoevenagel condensation with (dimethylamino)benzaldehyde and (ii) subsequent Bingel functionalization of the free malonate moiety with C-60. These dyads have been spectroscopically characterized and studied by UV/Vis spectroscopy. Their ability to form stable complexes with europium triflate, thus forming a complex three-component supramolecular system with UV/Vis absorption characteristics clearly dependent on the overall distance between the interacting units, has been assessed quantitatively.