Highly Regioselective Derivatization of Trimetallic Nitride Templated Endohedral Metallofullerenes via a Facile Photochemical Reaction
Highly Regioselective Derivatization of Trimetallic Nitride Templated Endohedral Metallofullerenes via a Facile Photochemical Reaction
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DOI：
10.1021/ja804909t
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发表时间：
2008-12-31
影响因子：
15
通讯作者：
Gibson, Harry W.
中科院分区：
文献类型：
--
作者：
Shu, Chunying;Slebodnick, Carla;Gibson, Harry W.
光化学产生的苄基自由基与 Sc3N@C-80-I-h 反应生成二苄基加合物 [Sc3N@C-80(CH2C6H5)(2)]，产率 82%，具有高区域选择性。加合物的 H-1 谱显示出高度对称性：仅观察到亚甲基质子的一种 AB 模式。 C-13 NMR 谱表明具有 C-2 对称结构。 DFT 计算表明，1,4-加合物比 1,2-加合物有利 > 10 kcal/mol。 X 射线晶体学分析明确证实了 [566] 环连接处的 1,4-结构。紫外可见光谱显示，从笼的 pi 系统中去除两个 p 轨道以及苄基取代基会改变金属富勒烯的电子特性，其方式与报道的二硅烷和三氟甲基部分类似。在与 LU3N@C-80-I-h 相同的条件下，我们制备了（产率 63%）Lu3N@C-80(CH2C6H6)(2)，其性能类似于 SC3N@C-80-I-h 的 1,4-二苄基加合物。
Photochemically generated benzyl radicals react with Sc3N@C-80-I-h to produce a dibenzyl adduct [Sc3N@C-80(CH2C6H5)(2)] in 82% yield and high regioselectivity. The adduct's H-1 spectrum revealed high symmetry: only one AB pattern was observed for the methylene protons. The C-13 NMR spectrum suggested a C-2-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 pi 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@C-80-I-h we prepared (63% yield) Lu3N@C-80(CH2C6H6)(2), which demonstrated properties similar to the 1,4-dibenzyl adduct of SC3N@C-80-I-h.