Xiao Dongyi, Yu Qianyue, Yi Haifeng, Zhang Yan, Robinson Gregory H, Schaefer Henry F
College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
Center for Computational Quantum Chemistry, University of Georgia, Athens, Georgia 30602, United States.
Inorg Chem. 2025 Feb 10;64(5):2433-2442. doi: 10.1021/acs.inorgchem.4c04865. Epub 2025 Jan 27.
The isolation of nucleophilic boron bases has led to a paradigm shift in boron chemistry. Previous studies of the bis(carbene) borylene complexes revealed that these compounds possess strong donor abilities, and their reaction inertness is due to the large steric hindrance between boron reagents and reactant. In the present study, we have theoretically studied the [(N)BX] and [(N)BX] compounds (X = H, F, Cl, Br). Their electronic structures and properties are discussed by using the NBO, LOL, and ELF methods. We found that both π-conjugation and hyperconjugation effects can effectively stabilize the substituted nucleophilic anionic boron compounds [(N)BX] and [(N)BX]. Substituents, especially X = H, stabilize the boron center through highly delocalized π-bonding, involving the formally "empty" in-plane orbitals of the boron atom. While the halogen substituents have high electron withdrawal ability, leading to systems being less stable, we suggest the borinium anions [(N)BH] and [(N)BH] as possible synthetic targets of novel environmentally friendly catalysts.
亲核性硼碱的分离导致了硼化学领域的范式转变。之前对双（卡宾）硼烯配合物的研究表明，这些化合物具有很强的给体能力，其反应惰性归因于硼试剂与反应物之间的巨大空间位阻。在本研究中，我们对[(N)BX]和[(N)BX]化合物（X = H、F、Cl、Br）进行了理论研究。通过使用NBO、LOL和ELF方法对它们的电子结构和性质进行了讨论。我们发现，π共轭和超共轭效应都能有效地稳定取代的亲核阴离子硼化合物[(N)BX]和[(N)BX]。取代基，尤其是X = H，通过高度离域的π键作用稳定硼中心，这种π键作用涉及硼原子形式上“空”的面内轨道。虽然卤素取代基具有较高的吸电子能力，导致体系稳定性较低，但我们建议硼鎓阴离子[(N)BH]和[(N)BH]作为新型环境友好催化剂的可能合成目标。
