▎ 摘　　要

Rationale: Graphene has proved to be a versatile precursor for the generation of mono-endohedral metallofullerenes (EMFs) of alkali and alkali earth metal atoms. Thus, it is important to investigate whether graphene is also a good precursor for the generation of EMFs including multi-metal atoms or some transition metal atoms. Methods: Experiments were performed on a 7.0T Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Laser ablation mass spectra were obtained by laser irradiation on mixtures of graphene and LaCl3, YCl3 or HAuCl4 on a stainless steel plate. A 355nm Nd:YAG laser with a typical energy of 2.5mJ/pulse was employed in these experiments. Tandem mass spectrometry was performed by on-resonance excitation collision-induced dissociation (CID) for selected single isotopic peaks. Results: Metallofullerene La1-6C2m+/Y1-6C2m+ ions were observed in the laser ablation mass spectra of mixtures of graphene and LaCl3/YCl3. CID and reactant gas experiments on selected ions showed that these ions had endohedral structures. Considering the experimental condition applied here, a mechanism based on a top-down process for the generation of the EMF ions is suggested. Further experiments on HAuCl4 showed some weak signals of AuC2m+ for the first time. Conclusions: Mono- and multi-EMF ions of MnC2m+ (M = La, Y, n=1-6, 50