Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Chemistry. 2012 Nov 5;18(45):14292-304. doi: 10.1002/chem.201202345. Epub 2012 Sep 27.
Herein, we report the synthesis of boroles that are linked by a conjugated phenylene spacer. The characterization of these compounds was completed by NMR and UV/Vis spectroscopy, as well as X-ray crystal diffraction. Furthermore, the coordination behavior of these oligoboroles towards five electronically and sterically disparate pyridine derivatives was studied and revealed fundamental differences in the properties of the resulting adducts. The experimental results were supported by density functional theory (DFT) calculations that showed a charge-transfer effect upon formation of the pyridine-4-carbonitrile adduct. By chemical reduction of a tris(borolyl)-substituted benzene derivative, a hexaanion was isolated as a result of a two-electron reduction of each borolyl moiety. The interaction of the borolyl units through the aryl spacer, and the possible increase of the Lewis acidity due to the conjugation of the borolyl moieties, were investigated by base transfer reactions.
在此，我们报告了通过共轭亚苯基间隔基连接的硼烷的合成。通过 NMR 和 UV/Vis 光谱以及 X 射线晶体衍射完成了这些化合物的表征。此外，还研究了这些寡硼烷与五个电子和空间位阻不同的吡啶衍生物的配位行为，揭示了所得加合物性质的基本差异。实验结果得到了密度泛函理论（DFT）计算的支持，表明在形成吡啶-4-腈加合物时存在电荷转移效应。通过对三（硼烷）取代苯衍生物进行化学还原，每个硼烷部分的两电子还原导致分离出六阴离子。通过碱基转移反应研究了通过芳基间隔基的硼烷单元相互作用，以及由于硼烷部分的共轭而可能增加的路易斯酸度。
