Exceptionally Long C-C Single Bonds in Diamino-o-carborane as Induced by Negative Hyperconjugation
Exceptionally Long C-C Single Bonds in Diamino-o-carborane as Induced by Negative Hyperconjugation
复制标题
由负超共轭诱导的二氨基邻碳硼烷中异常长的 C-C 单键
DOI：
10.1002/anie.201812555
复制
发表时间：
2019-01-28
影响因子：
16.6
通讯作者：
Mueller, Thomas
中科院分区：
文献类型：
--
作者：
Li, Junxia;Pang, Ronglin;Mueller, Thomas
本文报道了一系列1，2-二氨基-邻-碳硼烷（1-4）的合成。这些二氨基-o-碳硼烷的分子结构是显著的，因为簇内C-C键都是超长的（162.7-193.1 μ m），并且随着取代基的微小变化而显著变化。量子力学研究结果表明，键长的起源是邻碳硼烷中氮取代基的孤对电子与C-C键的σ * 轨道的面内负超共轭。
The synthesis of a series of 1,2-diamino-o-carboranes (1-4) is reported. The molecular structures of these diamino-o-carboranes are remarkable as the inner-cluster C-C bonds are all ultra-long (162.7-193.1 pm) and vary substantially with small variations in the substituents. The results of quantum mechanical investigations suggest that the origin of the bond elongation is significant in-plane negative hyperconjugation of lone pairs of the nitrogen substituents with the sigma* orbitals of the C-C bonds in o-carboranes.