Shao Xingxin, Liu Mengyu, Liu Jun, Wang Lixiang
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China.
Angew Chem Int Ed Engl. 2022 Aug 22;61(34):e202205893. doi: 10.1002/anie.202205893. Epub 2022 Jul 8.
We herein report an organoboron compound (SBN-1) based on N-B←N units with a balanced resonance hybrid of B, N single bond (B-N) and B, N coordination bond (B←N). Despite the different chemical environments of the two nitrogen atoms in the N-B←N unit, the single-crystal structure reveals that the two B, N bonds have similar bond lengths of ca. 1.55 Å and are almost equivalent. The resonance nature of the two B, N bonds contributes to the excellent chemical stability and photostability of SBN-1. The N-B←N units in SBN-1 show a strong electron-withdrawing capability and large dipole, resulting in a red-shifted absorption spectrum, downshifted LUMO/HOMO energy levels, and drastically altered molecular packing behaviors in solid state. SBN-1 can be used as a building block to construct small band gap conjugated polymers. The resonance of B, N bonds discovered in this work provides new insight into the design of stable organoboron small molecules and polymers for practical applications.
我们在此报告一种基于N-B←N单元的有机硼化合物（SBN-1），其具有B、N单键（B-N）和B、N配位键（B←N）的平衡共振杂化体。尽管N-B←N单元中两个氮原子的化学环境不同，但单晶结构表明两个B、N键具有相似的键长，约为1.55 Å，且几乎相等。两个B、N键的共振性质有助于SBN-1具有出色的化学稳定性和光稳定性。SBN-1中的N-B←N单元显示出很强的吸电子能力和大偶极矩，导致吸收光谱红移、LUMO/HOMO能级下移以及固态下分子堆积行为发生显著改变。SBN-1可用作构建小带隙共轭聚合物的结构单元。这项工作中发现的B、N键共振为设计用于实际应用的稳定有机硼小分子和聚合物提供了新的见解。
