Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021, Karlsruhe, Germany.
Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), P.O. Box 6980, 76049, Karlsruhe, Germany.
J Am Soc Mass Spectrom. 2019 Oct;30(10):1973-1980. doi: 10.1007/s13361-019-02250-2. Epub 2019 Jun 25.
We have used trapped ion mobility spectrometry (TIMS) to obtain highly accurate experimental collision cross sections (CCS) for the fullerene C and the endohedral metallofullerenes La@C, ScN@C, and ErN@C in molecular nitrogen. The CCS values of the endohedral fullerenes are 0.2% larger than that of the empty cage. Using a combination of density functional theory and trajectory calculations, we were able to reproduce these experimental findings theoretically. Two effects are discussed that contribute to the CCS differences: (i) a small increase in fullerene cage size upon endohedral doping and (ii) charge transfer from the encapsulated moieties to the cage thus increasing the attractive charge-induced dipole interaction between the (endohedral) fullerene ion and the nitrogen bath gas molecules.
我们使用离子阱淌度谱（TIMS）技术，在氮气环境中获得了高度精确的富勒烯 C 和金属内嵌富勒烯 La@C、ScN@C 和 ErN@C 的实验碰撞截面（CCS）。金属内嵌富勒烯的 CCS 值比空笼大 0.2%。通过结合密度泛函理论和轨迹计算，我们能够从理论上重现这些实验结果。讨论了两个导致 CCS 差异的因素：（i）金属内嵌掺杂后富勒烯笼的微小尺寸增加，以及（ii）被包封部分向笼转移电荷，从而增加了（内嵌）富勒烯离子与氮浴气体分子之间的吸引力电荷诱导偶极相互作用。
