The Unanticipated Dimerization of Ce@C2v(9)‐C82 upon Co‐crystallization with Ni(octaethylporphyrin) and Comparison with Monomeric M@C2v(9)‐C82 (M = La,Sc, and Y) |
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| Authors: | Prof. Mitsuaki Suzuki Prof. Michio Yamada Prof. Yutaka Maeda Dr. Satoru Sato Prof. Yuta Takano Prof. Filip Uhlík Prof. Zdenek Slanina Prof. Yongfu Lian Prof. Xing Lu Prof. Shigeru Nagase Prof. Marilyn M. Olmstead Prof. Alan L. Balch Prof. Takeshi Akasaka |
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| Affiliation: | 1. Department of Chemistry, Josai University, Saitama, Japan;2. Department of Chemistry, Tokyo Gakugei University, Tokyo, Japan;3. Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, Ibaraki, Japan;4. Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto, Japan;5. Department of Physical and Macromolecular Chemistry, Charles University in Prague, Prague 2, Czech Republic;6. Department of Chemistry and Biochemistry, National Chung-Cheng University, Chia-Yi, Taiwan R.O.C.;7. Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin, P.R. China;8. State Key Laboratory of Materials Processing and Die & Mold Technology, School of Materials Science and Engineering, Huazhong, University of Science and Technology, Wuhan, P.R. China;9. Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto, Japan;10. Department of Chemistry, University of California, Davis, California, USA;11. Foundation for Advancement of International Science, Tsukuba, Ibaraki, Japan |
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| Abstract: | We report that Ce@C2v(9)‐C82 forms a centrosymmetric dimer when co‐crystallized with Ni(OEP) (OEP = octaethylporphyrin dianion). The crystal structure of {Ce@C2v(9)‐C82}2?2[Ni(OEP)]?4 C6H6 shows that a new C?C bond with a bond length of 1.605(5) Å connects the two cages. The high spin density of the singly occupied molecular orbital (SOMO) on the cage and the pyramidalization of the cage are factors that favor dimerization. In contrast, the treatment of Ni(OEP) with M@C2v(9)‐C82 (M = La, Sc, and Y) results in crystallization of monomeric endohedral fullerenes. A systematic comparison of the X‐ray structures of M@C2v(9)‐C82 (M = Sc, Y, La, Ce, Gd, Yb, and Sm) reveals that the major metal site in each case is located at an off‐center position adjacent to a hexagonal ring along the C2 axis of the C2v(9)‐C82 cage. DFT calculations at the M06‐2X level revealed that the positions of the metal centers in these metallofullerenes M@C2v(9)‐C82 (M = Sc, Y, and Ce), as determined by single‐crystal X‐ray structure studies, correspond to an energy minimum for each compound. |
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| Keywords: | cage compounds crystal growth dimerization metallofullerenes structure elucidation |
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