Self-assembly of endohedral metallofullerenes: a decisive role of cooling gas and metal-carbon bonding.

摘要: The endohedral metallofullerene (EMF) self-assembly process in Sc/carbon vapor the presence and absence of an inert cooling gas (helium) is systematically investigated using quantum chemical molecular dynamics simulations. It revealed that He atoms accelerates formation pentagons hexagons reduces size self-assembled carbon cages comparison with analogous He-free As a result, Sc/C/He system simulations produce larger number successful trajectories (i.e. leading to Sc-EMFs) more realistic cage-size distribution than Sc/C system. main Sc encapsulation mechanism involves nucleation several already at early stages condensation. In such proto-cages, both Sc–C σ-bonds coordination bonds between π-system network are present. thus rather labile can move along network, but overall bonding sufficiently strong prevent dissociation even temperatures around 2000 kelvin. Further growth fullerene cage results one or two within fullerene. agreement experimental studies, extension Fe Ti as metal component showed Fe-EMFs not formed all, whereas prone form Ti-EMFs small sizes, including Ti@C28-Td Ti@C30-C2v(3).