Tridental molecular clip with corannulene pincers: is three better than two?

Abstract

A molecular clip 3 (C87H54O6) with cyclotriveratrylene tether and three corannulene pincers was synthesized and tested for its affinity toward fullerenes. 1H NMR titration experiment in toluene-d8 suggests the formation of 1:1 fullerene@3 complexes and provides the association constants of 1500±50 and 1180±30M−1 for C60 and C70, respectively, lower than those previously reported for buckycatcher 2 complexes with fullerenes. In comparison with 2, 3 offers one more corannulene pincer able to bind with the fullerene guests, but the potentially higher gas-phase binding energies of its inclusion complexes are overridden by the more severe entropy and/or solvation penalties associated with the supramolecule formation in solution.