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An unprecedented and straightforward supramolecular mask strategy to prepare exclusively equatorial bis-, tris-, and tetrakis-cyclopropanated-C 60 Bingel-Hirsch derivatives is reported. By taking advantage of the high affinity for fullerene of tetragonal prismatic supramolecular cages, a highly stable C 60 31a$(BArF) 8 hostguest complex is submitted to Bingel-Hirsch cyclopropanation reaction conditions. Regioselectivity is strictly dictated by the four cross-shaped apertures of the nanocapsule in a controlled fashion. Moreover, stepwise-cyclopropanated adducts up to tetrakis additions are obtained in excellent yields and purities.

Supramolecular nanocapsule 1⋅(BArF) is able to sequentially and selectively entrap recently discovered U @C and unprecedented Sc CU@C , simply by soaking crystals of 1⋅(BArF) in a toluene solution of arc-produced soot. These species, selectively and stepwise absorbed by 1⋅(BArF) , are easily released, obtaining highly pure fractions of U @C and Sc CU@C in one step. Sc CU@C represents the first example of a mixed metal actinide-based endohedral metallofullerene (EMF). Remarkably, the host-guest studies revealed that 1⋅(BArF) is able to discriminate EMFs with the same carbon cage but with different encapsulated cluster and computational studies provide support for these observations.

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The dynamic adaptability of tetragonal prismatic nanocapsule 1 8+ in the selective separation of fullerenes and endohedral metallofullerenes (EMFs) remains unexplored. Therefore, the essential molecular details of the fullerene recognition and binding process into the coordination capsule and the origins of fullerene selectivity remain elusive. In this work, the key steps of fullerene recognition and binding processes have been deciphered by designing a protocol which combines 1 H− 1 H exchange spectroscopy (2D-EXSY) NMR experiments, long time-scale Molecular Dynamics (MD) and accelerated Molecular Dynamics (aMD) simulations, which are combined to completely reconstruct the spontaneous binding and unbinding pathways from nanosecond to second timerange. On one hand, binding (k′ on ) and unbinding (k off ) rate constants were extracted from 1 H− 1 H exchange spectroscopy (EXSY) NMR experiments for both C 60 and C 70 . On the other hand, MD and aMD allowed monitoring the molecular basis of the encapsulation and guest competition processes at a very early stage under nonequilibrium conditions. The receptor capsule displays dynamical adaptability features similar to those observed in the process of biomolecular recognition in proteins. In addition, the encapsulation of bis-aza[60]fullerene (C 59 N) 2 within a supramolecular coordination capsule has been studied for the first time, showcasing the pros and cons of the dumbbell-shaped guest in the dynamics of the encapsulation process and in the stability of the final bound adduct. The powerful combination of NMR, MD, and aMD methodologies allows to obtain a precise picture of the subtle events directing the encapsulation and is thus a predictive tool for understanding host−guest encapsulation and interactions in numerous supramolecular systems.