Carbon Pyramidalization in Fullerene Cages Induced by the Endohedral Cluster: Non-Scandium Mixed Metal Nitride Clusterfullerenes

摘要

Metal nitride clusterfullerenes (NCFs) represent a special class of endohedral fullerenes with an encaged trimetallic nitride cluster. One of the characteristic features of the NCFs with homogeneous M3N clusters is that the structure of the cluster is determined by its size which varies with the radius of the involved metal. The mixed metal nitride clusterfullerenes (MMNCFs), that is, the nitride clusterfullerenes with different metals mixed in the encaged nitride, are recognized as a small group within the NCF family. A noteworthy feature of MMNCFs is that their yields can be higher than those of homogeneous NCFs. Such an advantage makes MMNCFs a promising route to boosting the yield of clusterfullerenes, which is often low for homogeneous NCFs incorporating large metal ions. So far a number of MMNCFs have been isolated, including MSc2N@C_(80)(I_h) (M = Y, Ce, Gd, Tb, Er), M2ScN@C_(80) (4) (M = Y, Gd, Er), Gd_xSc_(3-x)N@C_(80) (D_(5h)) (x = 1,2), ScYErN@C_(80) (I_h), DySc2N@C_(76), MSc2N@C_(68)(M=Dy, Lu), Lu2ScN@C_(68). Note that, in all cases, the involvement of Sc was essential to direct the formation of these MMNCFs, because Sc-based NCFs are known to have higher yields, compared to homogeneous NCFs with other metals.