title: An improbable monometallic cluster entrapped in a popular fullerene cage: YCN@C(s)(6)-C82.
abstract: Since the first proposal that fullerenes are capable of hosting atoms, ions, or clusters by the late Smalley in 1985, tremendous examples of endohedral metallofullerenes (EMFs) have been reported. Breaking the dogma that monometallofullerenes (mono-EMFs) always exist in the form of M@C2n while clusterfullerenes always require multiple (two to four) metal cations to stabilize a cluster that is unstable as a single moiety, here we show an unprecedented monometallic endohedral clusterfullerene entrapping an yttrium cyanide cluster inside a popular C82 cage--YCN@C(s)(6)-C82. X-ray crystallography and (13)C NMR characterization unambiguously determine the cage symmetry and the endohedal cyanide structure, unexpectedly revealing that the entrapped YCN cluster is triangular. The unprecedented monometallic clusterfullerene structure unveiled by YCN@C(s)(6)-C82 opens up a new avenue for stabilizing a cluster by a single metal cation within a carbon cage, and will surely stimulate further studies on the stability and formation mechanism of EMFs.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale & Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China. sfyang@ustc.edu.cn
authors.forename: Shangfeng
authors.initials: S
authors.lastname: Yang
authors.forename: Chuanbao
authors.initials: C
authors.lastname: Chen
authors.forename: Fupin
authors.initials: F
authors.lastname: Liu
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Xie
authors.forename: Fengyu
authors.initials: F
authors.lastname: Li
authors.forename: Mingzhi
authors.initials: M
authors.lastname: Jiao
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Tao
authors.initials: T
authors.lastname: Wei
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Chen
authors.forename: Xing
authors.initials: X
authors.lastname: Lu
authors.forename: Takeshi
authors.initials: T
authors.lastname: Akasaka