Synthesis and regiochemistry of [60]fullerenyl 2-methylmalonate bisadducts and their facile electron-accepting properties.
Synthesis and regiochemistry of [60]fullerenyl 2-methylmalonate bisadducts and their facile electron-accepting properties.
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DOI：
10.1021/jo1007674
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发表时间：
2010-07-02
影响因子：
3.6
通讯作者：
Chiang, Long Y.
中科院分区：
文献类型：
--
作者：
Kokubo, Ken;Arastoo, Riyah S.;Oshima, Takumi;Wang, Chun-Chih;Gao, Yuan;Wang, Hsing-Lin;Geng, Hao;Chiang, Long Y.
本文描述了在优先生成C602−的过程中，使用原位化学生成的NaN作为电子还原剂的简单的一锅反应。C602-−中间体与两种空间受阻的2-溴-2-甲基丙二酸酯的摩尔等价物形成两个单键的富勒烯基双加合物C60[-CME(CO2Et)2]2，产率分别为35%和7%。通过核磁共振、UV-Vis-NIR、LC MS和X-射线单晶结构分析，确定这两个产物的区域化学结构分别为1，4-和1，16-双加合物。与主要的1，4-双加成物和纯C60相比，次要的1，16-双加成物2在近红外区有较长的吸收带，并具有显著的电子接受特性。通过密度泛函计算，我们认为2的这些异常特征起源于[18π]-反式烯，与C60，EF-6MCn的高度对称的翡翠绿1，16，29，38，43，60-六加成物非常相似。因此，我们预计，通过考虑相应的区域化学和电子性质，在C60笼子上将快速渐进地形成看似1，16-双加成物样的中间部分，作为导致EF-6MCn形成的前体结构。
A simple one-pot reaction using in situ chemically generated Na-naphthalenide as an electron reductant in the preferential generation of C602− is described. Trapping of C602− intermediate with two molar equivalents of sterically hindered 2-bromo-2-methylmalonate ester afforded two singly bonded fullerenyl bisadducts C60[-CMe(CO2Et)2]2 in 35 and 7% yield, respectively. The regiochemistry of these two products were determined to be 1,4- and 1,16-bisadducts, respectively, by NMR, UV-Vis-NIR, LCMS, and X-ray single crystal structural analysis. The minor 1,16-bisadduct 2 exhibits long wavelength absorption bands in near-IR region and the prominent electron-accepting characteristics as compared with those of the major 1,4-bisadduct and pristine C60. As revealed by DFT calculation, we propose that the origin of these unusual characters of 2 arises from the moiety of [18π]-trannulene, in close resemblance to that of the highly symmetrical emerald green 1,16,29,38,43,60-hexaadduct of C60, EF-6MCn. Accordingly, we anticipate a fast progressive formation of plausible 1,16-bisadduct-like intermediate moieties on a C60 cage as the precursor structure leading to the formation of EF-6MCn, by taking the corresponding regiochemistry and electronic properties into account.
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影响因子：
1.6
作者：
Canteenwala, Taizoon;Li, Wenguang;Chiang, Long Y.
通讯作者：
Chiang, Long Y.
影响因子：
5.2
作者：
Cheng, FY;Murata, Y;Komatsu, K
通讯作者：
Komatsu, K
影响因子：
5.2
作者：
Allard, E;Delaunay, J;Cousseau, J
通讯作者：
Cousseau, J
影响因子：
15
作者：
Canteenwala, T;Padmawar, PA;Chiang, LY
通讯作者：
Chiang, LY
影响因子：
15
作者：
Fokin, AA;Jiao, H;Schleyer, PV
通讯作者：
Schleyer, PV