▎ 摘　　要

We present a first-principles modeling study of a new class of nanomaterials in which buckminsterfullerene (C-60) and graphene (G) are bridged by Cr via coordination bonds. Two nanostructures denoted as G(C-54)Cr- C-60 and G(C-150)-Cr-C-60 are investigated, which share many similarities in the configuration geometries but differ in the distribution densities of Cr-C-60 on the graphene surface. The binding energies between C-60 and the rest of the system in these complexes are calculated to be 2.59 and 2.10 eV, respectively, indicative of their good structural stability. Additional spin-polarized calculations indicate that G(C-54)-Cr-C-60 is weakly ferromagnetic, which is chiefly due to the contribution from the 3d shell of Cr. We then investigate three model complexes of C-60-Cr-G(C-54) and a metal cluster (Ni-4, Pd-4, or Pt-4). The binding energies of these three nanostructures are significantly large (3.57, 2.38, and 4.35 eV, respectively). Electron density analysis along the Ni-C, Pd-C, and Pt-C bonds consistently affirms that the Pt-C bond is the strongest while the Pd-C bond is the weakest. The strong Pt-C bond is attributed to the effective overlap of 5dz2 (Pt) and 2pz (C) orbitals. Partial density of states analysis indicates that Ni-4 and Pd-4 substantially contribute to the strong ferromagnetism of the complexes, whereas Pt-4 is observed to be non-magnetic even when the spin-orbit coupling is taken into account. H-2 dissociation on the Ni-4 complex is also examined, and the estimated reaction barrier is relatively low (0.76 eV).