Qin Yingying, Zheng Gang, Guo Yan, Gao Fangfang, Ma Jiani, Sun Wei, Xie Gang, Chen Sanping, Wang Yaoyu, Sun Huaming, Li Anyang, Wang Wenyuan
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
Gaoxin No. 1 High School, Xi'an, 710065, P. R. China.
Chemistry. 2020 May 15;26(28):6122-6125. doi: 10.1002/chem.202000836. Epub 2020 May 8.
The first isolable silylene-germylene complex 5 was assembled by a salt metathesis reaction between the germylene anion 3 and the N-heterocyclic chlorosilylene 4, and structurally characterized. The central structure of 5 demonstrates a remarkable gauche-bent geometry with the silylene and germylene units, which are interconnected by a Si-Ge bond with a length of 2.4498(9) Å. This value is not only perceptibly longer than the distances known in doubly bonded germasilenes, and also slightly longer than those in germylsilanes. The DFT calculations on 5 confirmed a nearly nonpolar Si -Ge single-bond nature and its bonding orbital, as well as the aromaticity of the C NGe-rings in 3 and 5. The latter increases the molecular stability of 3 and 5, and makes the preparation of silylene-germylene complex 5 a reality.
首个可分离的硅烯-锗烯配合物5是通过锗烯阴离子3与氮杂环氯硅烯4之间的盐复分解反应组装而成，并对其结构进行了表征。5的中心结构显示出硅烯和锗烯单元具有显著的gauche弯曲几何形状，它们通过长度为2.4498(9) Å的Si-Ge键相互连接。该值不仅明显长于已知的双键锗硅烯中的距离，也略长于锗基硅烷中的距离。对5的密度泛函理论计算证实了其近乎非极性的Si-Ge单键性质及其成键轨道，以及3和5中C NGe环的芳香性。后者提高了3和5的分子稳定性，并使硅烯-锗烯配合物5的制备成为现实。
