2022-10-24：余鹏威在Nanoscale发表论文

Steering Lu3N cluster in C76-78 cages: Cluster configuration dominated by cage transformation

Pengwei Yu, Shuaifeng Hu, Xinyue Tian, Wangqiang Shen, Pengyuan Yu, Kun Guo, Yunpeng Xie, Lipiao Bao* and Xing Lu*

Nanoscale, 2022.    https://doi.org/10.1039/D2NR05049H

Abstract

While the strong interaction between the internal unit and the fullerene cage inside metallofullerenes is widely acknowledged, how the cage transformation interacts with the cluster configuration remains elusive. For this purpose, we herein captured three metallofullerene molecules with easy-to-compare cluster configuration and cage arrangement, namely Lu₃N@C_s(17490)-C₇₆, Lu₃N@C₂(22010)-C₇₈, and Lu₃N@D_3h(5)-C₇₈. The three lutetium-based nitride clusterfullerenes (NCFs) with small C_76-78 carbon cages were synthesized by a modified arc-discharge method and their structures are unambiguously confirmed by X-ray crystallography. Notably, the cage transformation from C_s(17490)-C₇₆ to C₂(22010)-C₇₈via a simple C₂-unit insertion leads to a remarkable configuration change of the encapsulated Lu₃N cluster from an unusual asymmetric plane to a common symmetric one. This close correlation between the cluster configuration and cage transformation is further confirmed by the pyramidal Lu3N cluster in Lu₃N@D_3h(5)-C₇₈ other than the symmetric planar Lu₃N unit in Lu₃N@C₂(22010)-C₇₈, as a result of an even larger difference in the cage arrangement. Astonishingly, such a cluster shrinkage, accompanied by an increase in cage size from C_s(17490)-C₇₆ to D_3h(5)-C₇₈, is dramatically opposite to the cluster expansion with cage elongation found in La₂C₂- or Y₂C₂-based metallofullerenes.

摘要：关于金属富勒烯中内嵌金属团簇与外部碳笼间的强相互作用已有广泛认知，但是碳笼转化对团簇构型的影响尚不清楚。为此，我们合成并表征了三种金属富勒烯，分别是Lu₃N@C_s(17490)-C₇₆、Lu₃N@C₂(22010)-C₇₈和Lu₃N@D_3h(5)-C₇₈，它们具有易于比较的团簇构型和碳笼结构。值得注意的是，通过简单的C₂单元插入，C_s(17490)-C₇₆碳笼可转化为C₂(22010)-C₇₈，同时导致内部Lu₃N团簇的构型发生显著的变化。碳笼转化与团簇构型这一紧密的联系也由Lu₃N@C₂(22010)-C₇₈和Lu₃N@D_3h(5)-C₇₈的结构比较进一步证实。C₂(22010)-C₇₈到D_3h(5)-C₇₈的转化使得Lu₃N团簇结构出现角锥化。