Synthesis and complexation study of new ExTTF-based hosts for fullerenes

A new series of exTTF hosts has been synthesized for supramolecular binding study of fullerenes C₆₀ and C₇₀. Binding constants for C₆₀ in chlorobenzene, toluene, toluene–CH₂Cl₂ and CS₂ have been calculated for different hosts and a direct structure–affinity relationship has been established. As predicted, receptors with two exTTF moieties (1, 3 and 4) have demonstrated higher binding abilities toward C₇₀ than C₆₀. Depending on the linker used to attach the exTTF unit to the core of the host, different binding modes (1 : 1 and 2 : 1) have been obtained.