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

A molecular clip 3 (C87H54O6) with cyclotriveratrylene tether and three corannulene pincers was synthesized and tested for its affinity toward fullerenes. H-1 NMR titration experiment in toluene-d(8) suggests the formation of 1:1 fullerene@3 complexes and provides the association constants of 1500 +/- 50 and 1180 +/- 30 M-1 for C-60 and C-70, 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. (C) 2013 Elsevier Ltd. All rights reserved.