†Institut für Anorganische Chemie, Georg-August-Universität, Tammannstraße 4, 37077 Göttingen, Germany.
∥Chemistry Department, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
J Am Chem Soc. 2015 May 20;137(19):6180-3. doi: 10.1021/jacs.5b03407. Epub 2015 May 12.
A cyclic alkyl(amino) carbene (cAAC) stabilized dimer [(cAAC)Si(P-Tip)]2 (2) (Tip = 2,4,6-triisopropylphenyl) is reported. 2 can be considered as a dimer of the heavier ketenimine (R2C═C═N-R) analogue. The dark-red rod-shaped crystals of 2 were synthesized by reduction of the precursor, cAAC-dichlorosilylene-stabilized phosphinidene (cAAC)SiCl2→P-Tip with sodium napthalenide. The crystals of 2 are storable at room temperature for several months and stable up to 215 °C under an inert atmosphere. X-ray single-crystal diffraction revealed that 2 contains a cyclic nonplanar four-membered SiPSiP ring. Magnetic susceptibility measurements confirmed the singlet spin ground state of 2. Cyclic voltammetry of 2 showed a quasi-reversible one-electron reduction indicating the formation of the corresponding radical anion 2(•-), which was further characterized by EPR measurements in solution. The electronic structure and bonding of 2 and 2(•-) were studied by theoretical calculations. The experimentally obtained data are in good agreement with the calculated values.
报道了一种环状烷基（氨基）卡宾（cAAC）稳定的二聚体[(cAAC)Si(P-Tip)]2（2）（Tip=2,4,6-三异丙基苯基）。2 可以被认为是较重的亚烯酮亚胺（R2C═C═N-R）类似物的二聚体。深红色棒状晶体 2 通过还原前体[cAAC-二氯硅基-稳定的膦亚基]（cAAC）SiCl2→P-Tip 与萘基钠制备得到。2 的晶体在室温下可稳定保存数月，在惰性气氛下可稳定至 215°C。X 射线单晶衍射表明 2 含有一个环状非平面四元 SiPSiP 环。磁化率测量证实了 2 的单重态自旋基态。2 的循环伏安法显示出准可逆的单电子还原，表明形成了相应的自由基阴离子 2(•-)，通过溶液中的 EPR 测量进一步对其进行了表征。通过理论计算研究了 2 和 2(•-)的电子结构和键合。实验获得的数据与计算值吻合良好。
