Department of Chemistry, Brown University, Providence, RI, 02912, USA.
Angew Chem Int Ed Engl. 2017 Aug 1;56(32):9551-9555. doi: 10.1002/anie.201705209. Epub 2017 Jun 30.
Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB O and Bi B , containing triple and double B-Bi bonds are presented. The BiB O and Bi B clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB O ([Bi≡B-B≡O] ) and Bi B ([Bi=B=Bi] ), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding.
尽管硼原子缺少一个电子，但它在形成多重键方面具有多样性。已知过渡金属-硼双键，但硼-金属三键一直难以捉摸。本文提出了两种含有三键和双键的双铋硼簇阴离子 BiBO 和 BiB。通过激光蒸发混合的 B/Bi 靶材产生了 BiBO 和 BiB 团簇，并通过光电子能谱和从头算计算进行了表征。借助从头算计算获得了分辨率良好的光电子能谱，并对其进行了解释，结果表明这两种物质均呈线性。化学键分析表明，BiB O 中的 Bi 与硼形成三键和双键([Bi≡B-B≡O])，而 BiB 中的 Bi 与硼形成双键([Bi=B=Bi])。计算得出的 Bi-B 双键和三键的键强度分别为 3.21 和 4.70 eV。这是首次对 Bi-B 双键和三键的实验观察，为设计具有多重键的主族金属-硼配合物开辟了道路。
