A two-coordinate boron cation featuring C-B+-C bonding.
A two-coordinate boron cation featuring C-B+-C bonding.
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DOI：
10.1038/nchem.1948
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发表时间：
2014-06
期刊：
影响因子：
21.8
通讯作者：
Yoshiaki Shoji;N. Tanaka;K. Mikami;M. Uchiyama;T. Fukushima
中科院分区：
文献类型：
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作者：
Yoshiaki Shoji;N. Tanaka;K. Mikami;M. Uchiyama;T. Fukushima
双配位硼阳离子（R2B+），称为硼离子，是一种硼只携带四个价电子的化学物质，与假设的碳指示（R2C2+）是等电子的。虽然孤对供体取代基，如氨基，已经使几个硼离子的分离，二芳化和二烷基化的硼衍生物仍然完全未被探索。本文介绍了维密基硼离子的合成、结构和反应性，它表现出出乎意料的高热稳定性。在密度泛函理论计算的支持下，x射线晶体学和11b核磁共振谱分析表明，硼离子在固态和溶液中均呈线性二坐标结构。硼的中心由二甲基的π键稳定，不受反离子或溶剂分子的配位。这个二乙基硼离子具有特殊的路易斯酸，从二氧化碳中接受一对电子，引起不寻常的脱氧反应。
Two-coordinate boron cations (R2B+), referred to as borinium ions, are chemical species in which the boron bears only four valence electrons, and that are isoelectronic with hypothetical carbon dications (R2C2+). Although lone-pair-donating substituents such as amino groups have enabled the isolation of several borinium ions, diarylated and dialkylated borinium derivatives remain entirely unexplored. Here, we present the synthesis, structure and reactivity of the dimesitylborinium ion, which displays unexpectedly high thermal stability. X-ray crystallography and11B NMR spectroscopy, supported by density functional theory calculations, reveal that the borinium ion adopts a linear two-coordinate structure in both the solid state and in solution. The boron centre is stabilized bypπbonding from the mesityl groups and is free from coordination by the counterion or solvent molecules. This diarylborinium ion possesses exceptional Lewis acidity, accepting a pair of electrons from CO2to cause an unusual deoxygenation reaction.