金属富勒烯的质谱研究

利用电弧放电法合成笼内金属富勒烯Gd@C₈₂,Gd₂@C₈₀,Gd@C₈₀实验结果表明,两步高温高压法(1,2,4-三甲基苯,吡啶)可有效地提取金属富勒烯Gd@C₈₂.本文分别利用ESI-MS,REC-MS,MALDI-TOF-MS质谱技术研究了Gd@C₈₂,Gd₂@C₈₀,Gd@C₈₀和富勒烯Cn(n=60,70,82,84…)的气相负离子特性.结果表明,包入Gd³⁺后非极性的C₈₂转变为极性的Gd@C₈₂分子;金属离子Gd³⁺处于C₈₂^3-笼中非中心的位置.

Mass Spectrometric Studies of Metallofullerene

The endrohel metallofullerene, Gd@C82, Gd@C80, Gd2@C80 were synthesized by using K-H method. The technique of two-step of high pressure and high temperature extraction with 1,3,5-trimethylbenzene(first step) and pyridine(second step) has been successfully utilized to extract metallofullerene of Gd@C82. The gas-phase negative ions of fullerenes Cn(n=60, 70, 78, 82, 84…) and metallofullerene (Gd@C82) have been studied by the ESI-MS, REC-MS and MALDI-TOF-MS. The differences among the mass spectra of ESI-MS, REC-MS and MALDI-TOF-MS have been observed and explained. In contrast to the empty fullerene C82, the metallofullerene Gd@C82 should have a larger HOMO-LUMO gap. Experimental results suggest that Gd@C82 is polarized and Gd3+ located in the off-center position of C82 cage after Gd3+ is trapped into C82 cage.