Bis-corannulene Receptors for Fullerenes Based on Klärner’s Tethers: Reaching the Affinity Limits

Bis-corannulene
receptors 4 and 5 with
Klärner’s tethers prepared by the Diels–Alder
cycloaddition form inclusion complexes with C60 and C70, as evidenced by 1H NMR titration. While 4 exhibits affinity toward fullerenes comparable to the previously
reported corannulene-based receptors, 5 exceeds the performance
of the former systems by ca. 2 orders of magnitude and, in addition,
shows an enhanced preference for C70 over C60. The X-ray crystal structure of C60@5 and
DFT calculations indicate that the tether in 5 not only
preorganizes the pincers into a proper topology of the host but also
contributes to the dispersion-based binding with the fullerene guests.