Isolation of Three Isomers of Sm@C84 and X-ray Crystallographic Characterization of Sm@D3d(19)-C84 and Sm@C2(13)-C84

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• 作者：Hua Yang ; Meilan Yu ; Hongxiao Jin ; Ziyang Liu ; Mingguang Yao ; Bingbing Liu ; Marilyn M. Olmstead ; Alan L. Balch
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：March 21, 2012
• 年：2012
• 卷：134
• 期：11
• 页码：5331-5338
• 全文大小：449K
• 年卷期：v.134,no.11(March 21, 2012)
• ISSN：1520-5126

文摘

Three isomers with the composition Sm@C₈₄ were isolated from carbon soot obtained by electric arc vaporization of carbon rods doped with Sm₂O₃. These isomers were labeled Sm@C₈₄(I), Sm@C₈₄(II), and Sm@C₈₄(III) in order of their elution times during chromatography on a Buckyprep column with toluene as the eluent. Analysis of the structures by single-crystal X-ray diffraction on cocrystals formed with Ni^II(octaethylporphyrin) reveals the identities of two of the isomers: Sm@C₈₄(I) is Sm@C₂(13)-C₈₄, and Sm@C₈₄(III) is Sm@ D_3d(19)-C₈₄. Sm@C₈₄(II) can be identified as Sm@C₂(11)-C₈₄ on the basis of the similarity of its UV/vis/NIR spectrum with that of Yb@C₂(11)-C₈₄, whose carbon cage has been characterized by ¹³C NMR spectroscopy. Comparison of the three Sm@C₈₄ isomers identified in this project with two prior reports of the preparation and isolation of isomers of Sm@C₈₄ indicate that five different Sm@C₈₄ isomers have been found and that the source of samarium used for the generation of fullerene soot is important in determining which of these isomers form.