Highly Regioselective Derivatization of Trimetallic Nitride Templated Endohedral Metallofullerenes via a Facile Photochemical Reaction

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• 作者：Chunying Shu ; Carla Slebodnick ; Liaosa Xu ; Hunter Champion ; Tim Fuhrer ; Ting Cai ; Jonathan E. Reid ; Wujun Fu ; Kim Harich ; Harry C. Dorn ; Harry W. Gibson
• 刊名：Journal of the American Chemical Society
• 出版年：2008
• 出版时间：December 31, 2008
• 年：2008
• 卷：130
• 期：52
• 页码：17755-17760
• 全文大小：343K
• 年卷期：v.130,no.52(December 31, 2008)
• ISSN：1520-5126

文摘

Photochemically generated benzyl radicals react with Sc₃N@C₈₀-I_h to produce a dibenzyl adduct [Sc₃N@C₈₀(CH₂C₆H₅)₂] in 82% yield and high regioselectivity. The adduct’s ¹H spectrum revealed high symmetry: only one AB pattern was observed for the methylene protons. The ¹³C NMR spectrum suggested a C₂-symmetrical structure. DFT calculations reveal that a 1,4-adduct is more favorable than a 1,2-adduct by >10 kcal/mol. The 1,4-structure on [566] ring junctions was unambiguously confirmed by X-ray crystallographic analysis. UV−vis spectra revealed that the removal of two p orbitals from the π system of the cage together with the benzylic substituents change the electronic properties of the metallofullerene in a manner similar to those reported for disilirane and trifluoromethyl moieties. Under the same conditions from Lu₃N@C₈₀-I_h we prepared (63% yield) Lu₃N@C₈₀(CH₂C₆H₅)₂, which demonstrated properties similar to the 1,4-dibenzyl adduct of Sc₃N@C₈₀-I_h.