A boron-boron coupling reaction between two ethyl cation analogues
A boron-boron coupling reaction between two ethyl cation analogues
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DOI：
10.1038/nchem.1776
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发表时间：
2013-12-01
期刊：
影响因子：
21.8
通讯作者：
Himmel, Hans-Joerg
中科院分区：
文献类型：
--
作者：
Litters, Sebastian;Kaifer, Elisabeth;Himmel, Hans-Joerg
通过元素-元素偶联反应从较小的分子结构单元设计较大的结构是合成化学的关键问题之一，因此为这种自下而上的方法开发了许多策略。一般的方案是两个具有相反极性的元素或两个自由基的耦合。在这里，我们表明，一个B-B耦合反应是可能的两个硼类似物的乙基阳离子之间，导致在形成一个前所未有的双阳离子四硼烷。该产品的菱形B-4核中的键合性质可以描述为通过三中心、两电子键连接的两个B-B单元，共享短对角线。我们的发现可能会导致长期追求的硼链聚合物的结构类似于β-SiB 3中的硅链。此外，该反应是多中心键合对反应性影响的主要教科书示例。
The design of larger architectures from smaller molecular building blocks by element-element coupling reactions is one of the key concerns of synthetic chemistry, so a number of strategies were developed for this bottom-up approach. A general scheme is the coupling of two elements with opposing polarity or that of two radicals. Here, we show that a B-B coupling reaction is possible between two boron analogues of the ethyl cation, resulting in the formation of an unprecedented dicationic tetraborane. The bonding properties in the rhomboid B-4 core of the product can be described as two B-B units connected by three-centre, two-electron bonds, sharing the short diagonal. Our discovery might lead the way to the long sought-after boron chain polymers with a structure similar to the silicon chains in beta-SiB3. Moreover, the reaction is a prime textbook example of the influence of multiple-centre bonding on reactivity.