Molecular Basis for the Recognition of Higher Fullerenes into Ureidopyrimidinone-Cyclotriveratrylene Self-Assembled Capsules

Fullerenes C-60, C-70, and C-84 may be readily encaged within a hydrogen-bonded dimeric capsule, based on two concave cyclotriveratrylene (CTV) scaffolds, each containing three self-complementary 2-ureido-4-[1H]-pyrimidinone (UPy) subunits. NMR spectroscopy and circular dichroism studies, complemented by dispersion-corrected DFT calculations, are reported with the aim of characterizing such capsule-fullerene complexes both structurally and energetically. Six fullerenes are considered: in agreement with experiments, calculations find that encapsulation is most favorable for C-84 (on a par with C-90), and follows the trend C-60