Reiß Fabian, Villinger Alexander, Brand Harald, Baumann Wolfgang, Hollmann Dirk, Schulz Axel
Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
Institut für Chemie, Universität Rostock, Albert-Einstein-Straße 3a, 18059, Rostock, Germany.
Chemistry. 2022 Jun 10;28(33):e202200854. doi: 10.1002/chem.202200854. Epub 2022 Apr 29.
The oxidation of silylated hydrazine, (Me Si) N-N(H)SiMe , with silver salts led to the formation of a highly labile hydrazinium-yl radical cation, [(Me Si) N-N(H)SiMe ] , at very low temperatures (decomposition > -40 °C). EPR, NMR, DFT and Raman studies revealed the formation of a nitrogen-centered radical cation along the N-N unit of the hydrazine. In the presence of the weakly coordinating anion [Al{OCH(CF ) } ] , crystallization and structural characterization in the solid state were achieved. The hydrazinium-yl radical cation has a significantly shortened N-N bond and a nearly planar N Si framework, in contrast to the starting material. According to DFT calculations, the shortened N-N bond has a total bond order of 1.5 with a π-bond order of 0.5. The π bond can be regarded as a three-π-electron, two-center bond.
硅烷基肼（Me₃Si）₂N-N(H)SiMe₃与银盐发生氧化反应，在极低温度下（分解温度＞-40°C）生成了一种极不稳定的肼鎓-基自由基阳离子[(Me₃Si)₂N-N(H)SiMe₃]⁺。电子顺磁共振（EPR）、核磁共振（NMR）、密度泛函理论（DFT）和拉曼光谱研究表明，沿着肼的N-N单元形成了一个以氮为中心的自由基阳离子。在弱配位阴离子[Al{OCH(CF₃)₂}₄]⁻存在的情况下，实现了固态下的结晶和结构表征。与起始原料相比，肼鎓-基自由基阳离子的N-N键明显缩短，且N-Si骨架近乎平面。根据DFT计算，缩短后的N-N键总键级为1.5，π键级为0.5。该π键可视为一个三π电子、双中心键。
