Centres de Recerca de Catalunya (CERCA)
2016
<p> Fullerenes C<sub>60</sub>, C<sub>70</sub>, and C<sub>84</sub> may be readily encaged within a hydrogen-bonded dimeric capsule, based on two concave cyclotriveratrylene (CTV) scaffolds each bearing three self-complementary 2-ureido-4-[<em>1H</em>]-pyrimidinone (UPy) subunits. We herein report NMR and CD studies—complemented by dispersion-corrected density functional theory calculations—aiming to characterize such capsule-fullerene complexes both structurally and energetically. Six fullerenes are considered: in agreement with experiment, calculations find that encapsulation is most favorable for C<sub>84</sub> (on a par with C<sub>90</sub>), and follows the trend C<sub>60</sub><C<sub>70</sub><C<sub>76</sub><C<sub>78</sub><C<sub>84</sub>≈C<sub>90</sub>. As also found by NMR, the most stable capsules are formed by monomers of identical stereochemistry; with UPy and the CTV’s OMe groups in mutual <em>anti</em> orientation; and UPy-CTV ethylene linkers within the capsular surface plane. Up to C<sub>78</sub>, encapsulation is favored by increasing host-guest contacts, but the trend is thereafter increasingly inhibited by growing capsule strain.</p>
English
selective purification of fullerenes, supramolecular chemistry, DFT, density functional theory, NMR, circular dichroism
Wiley
Chem. Eur. J.
CTQ2014-52824-R
SEV-2013-0319
MINECO
I+D+I Severo Ochoa Excellence Accreditation 2014–2018
Papers [1245]
