Isolation and characterization of 1,2-dilithio[tetrakis(trimethylsilyl)]ethane. The first crystal structure of nonconjugated 1,2-dilithioethane
Isolation and characterization of 1,2-dilithio[tetrakis(trimethylsilyl)]ethane. The first crystal structure of nonconjugated 1,2-dilithioethane
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1,2-二锂[四(三甲基甲硅烷基)]乙烷的分离和表征。
DOI：
10.1021/ja00192a042
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发表时间：
1989
影响因子：
15
通讯作者：
H. Sakurai
中科院分区：
文献类型：
--
作者：
A. Sekiguchi;T. Nakanishi;C. Kabuto;H. Sakurai
二锂化合物210对空气和湿气极其敏感，并且在暴露于微量空气时立即恢复到1。与H20和D20的反应分别干净地产生3a11和3b,12。与多聚甲醛的反应可能通过甲硅烷基的1, 2-阴离子重排得到4 (73%) 13。相反，电子转移反应与芳香酮发生。黄色晶体的 14* H 和 13C NMR 光谱表明，四氢呋喃的两个分子与锂紧密结合，因为 THF 的化学位移值与游离四氢呋喃的化学位移值显着不同。有趣的一点是，在 9.8-10.6 ppm 处观察到 2 的阴离子碳是未解析的倍数！由 13C 和 Li 自旋耦合产生。光谱在 220-298 K 的温度范围内（在甲苯-rf8 中）没有明显变化。由于负电荷，29Si 的化学位移与 1 相比稍微向上场移动（1 为 -8.4 ppm，2 为 -12.7 ppm）。 7Li NMR 信号出现在 1.39 ppm (y1/2= 9 Hz) 处，与烷基锂中的信号相似。 15 2 的结构已通过 X 射线明确确定
The dilithium compound 210 is extremely air and moisture sensitive and immediately reverted to 1 on exposure to traces of air. The reactions withH20 and D20 cleanlyproduced 3a11 and 3b, 12 respectively. The reaction with paraformaldehyde afforded 4 (73%) 13 probably via 1, 2-anionic rearrangement of the silyl group. In contrast, electron-transfer reactions took place with aromatic ketones. 14* H as well as 13C NMR spectroscopy of the yellow crystals reveals that two molecules of the tetrahydrofuran tightly binds to lithium since the values of the chemical shifts of THF are significantly different from those of the free one. An interesting point is that the anionic carbon of 2 was observed at 9.8-10.6 ppm as an unresolved multiple! resulting from 13C and Li spin coupling. The spectra did not change appreciably in the temperature range of 220-298 K (in toluene-rf8). The chemicalshift of 29Si slightly shifted to theupfield compared to 1 due to the negative charge (-8.4 ppm for 1,-12.7 ppm for2). 7Li NMR signal appeared at 1.39 ppm (y1/2= 9 Hz) similar to those inalkyllithiums. 15 The structure of 2 has been unequivocally determined by X-ray