具有 λ 4 坐标 Si II 原子的几何强迫烯
Arseni Kostenko1, Matthias Driess1
1Metalorganics and Inorganic Materials, Department of Chemistry , Technische Universität Berlin , Straße des 17. Juni 135, Sekr. C2 , 10623 Berlin , Germany.
Journal of the American Chemical Society
|December 1, 2018
概括
研究人员合成了一种具有创纪录的SiSi键长度的高协调性disiene. 这种分子表现出动态的SiSi键行为和两价反应性,同时充当dysilene和bisilene.
科学领域:
- 有机化学
- 无机化学
- 材料科学
背景情况:
- 由于其独特的电子和结构性质,高协调化合物具有显著的兴趣.
- 基的类型,通常是具有短Si键的反应性物种.
- 具有不寻常的粘合特性,如延长的SiSi距离的disilenes的合成和表征,提出了合成挑战和机遇.
研究的目的:
- 合成和表征第一个具有最长SiSi键距离的超协调烯.
- 为了研究这种新型二氧化中的Si键的动态行为.
- 探索合成化合物作为二烯和二烯物种的两价反应性.
主要方法:
- 通过一种新途径合成5,6-bis(amidinato silylenyl) 乙 (1).
- 用X射线结晶学来确定分子结构和SiSi键的长度.
- 可变温度核磁共振 (NMR) 光谱用于研究动态行为.
- 量子化学计算可以预测和理解电子属性和反应性.
- 与各种基质 (乙烯,二乙烯,二,二) 进行反应,以检测反应性.
主要成果:
- 合成并描述了第一个具有记录SiSi键距离2.623(1) Å的超协调型二烯.
- 单片烯部分之间的空间强迫的双定性相互作用被确定为延长SiSi键的原因.
- 可变温度的NMR光谱证实了SiSi键的动态收缩和延长,与量子化学预测一致.
- 化合物1表现出两价反应性:与和基的 [2+2] 循环添加产物,以及与 () 2 的二 () 0 复合物的形成.
结论:
- 通过成功合成具有前所未有的长度Si键的超协调烯,在化学中展示了新的可能性.
- 观察到的动态Si键行为突出显示了电子相互作用对-键的影响.
- 化合物1的两价反应性为其在各种化学转化中的应用开辟了道路,它既可以作为二烯的前体,也可以作为二烯的前体.
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