Isolable anion radical of blue disilene (tBu2MeSi)2Si=Si(SiMetBu2)2 formed upon one-electron reduction: synthesis and characterization.
Isolable anion radical of blue disilene (tBu2MeSi)2Si=Si(SiMetBu2)2 formed upon one-electron reduction: synthesis and characterization.
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DOI：
10.1021/ja040079y
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发表时间：
2004-07
影响因子：
15
通讯作者：
A. Sekiguchi;S. Inoue;M. Ichinohe;Yoriko Arai
中科院分区：
文献类型：
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作者：
A. Sekiguchi;S. Inoue;M. Ichinohe;Yoriko Arai
制备了高度扭曲的四(二叔丁基甲基甲硅烷基)二硅烯4，并在THF中与(t)BuLi反应，通过单电子还原产生二硅烯阴离子自由基5。阴离子自由基 5 以其锂盐的形式被分离出来，为对空气和湿度极其敏感的红色晶体。通过X射线晶体学建立了5的分子结构，显示出沿中心Si-Si键的近正交结构（扭转角为88度），长度为2.341(5)A，相对于4伸长了3.6%。5的有趣特征是中心Si原子之一具有自由基特征，而另一个Si原子具有硅基阴离子特征。对 (29)Si 核超精细耦合常数的电子自旋共振 (ESR) 研究表明，在 ESR 时间尺度上这些中心 Si 原子之间发生快速自旋交换。
The highly twisted tetrakis(di-tert-butylmethylsilyl)disilene 4 was prepared and reacted with (t)BuLi in THF, producing disilene anion radical 5 upon one-electron reduction. The anion radical 5 was isolated in the form of its lithium salt as extremely air- and moisture-sensitive red crystals. The molecular structure of 5 was established by X-ray crystallography, which showed a nearly orthogonal structure (twisting angle of 88 degrees ) along the central Si-Si bond, with a length of 2.341(5) A, which is 3.6% elongated relative to that of 4. The interesting feature of 5 is that one of the central Si atoms has radical character, whereas the other Si atom has silyl anion character. An electron spin resonance (ESR) study of the hyperfine coupling constants of the (29)Si nuclei indicates that rapid spin exchange occurs between these central Si atoms on the ESR time scale.