Institut für Anorganische Chemie, Georg-August-Universität , Tammannstraße 4, 37077 Göttingen, Germany.
J Am Chem Soc. 2015 Jan 14;137(1):150-3. doi: 10.1021/ja512089e. Epub 2014 Dec 31.
The unstable species dichlorosilylene was previously stabilized by carbene. The lone pair of electrons on the silicon atom of (carbene)SiCl2 can form a coordinate bond with metal-carbonyls. Herein we report that (carbene)SiCl2 can stabilize a phosphinidene (Ar-P, a carbone analogue) with the general formula carbene→SiCl2→P-Ar (carbene = cyclic alkyl(amino) carbene (cAAC; 2) and N-heterocyclic carbene (NHC; 3)). Compounds 2 and 3 are stable, isolable, and storable at 0 °C (2) to room temperature (3) under an inert atmosphere. The crystals of 2 and 3 are dark blue and red, respectively. The intense blue color of 2 arises due to the strong intramolecular charge transfer (ICT) transition from πSi═P→π*cAAC. The electronic structure and bonding of 2, 3 were studied by theoretical calculations. The HOMO of the molecule is located on the πSi═P bond, while the LUMO is located at the carbene moiety (cAAC or NHC). The dramatic change in color of these compounds from red (3, NHC) to blue (2, cAAC) is ascribed to the difference in energy of the LUMO within the carbenes (cAAC/NHC) due to a lower lying LUMO of cAAC.
先前，卡宾（carbene）稳定了二氯硅烯（dichlorosilylene）这一不稳定的物种。（卡宾）SiCl2 中硅原子上的孤对电子可以与金属羰基形成配位键。在此，我们报告（卡宾）SiCl2 可以稳定膦烯（Ar-P，一种类似碳的物质），其通式为 carbene→SiCl2→P-Ar（carbene = 环状烷基（氨基）卡宾（cAAC；2）和 N-杂环卡宾（NHC；3））。化合物 2 和 3 在 0°C（2）到室温（3）下在惰性气氛中稳定、可分离且可储存。2 和 3 的晶体分别为深蓝色和红色。2 的强烈蓝色源于从 πSi═P→π*cAAC 的强分子内电荷转移（ICT）跃迁。通过理论计算研究了 2、3 的电子结构和键合。分子的 HOMO 位于πSi═P 键上，而 LUMO 位于卡宾部分（cAAC 或 NHC）上。这些化合物的颜色从红色（3，NHC）变为蓝色（2，cAAC），这归因于卡宾（cAAC/NHC）中 LUMO 的能量差异，因为 cAAC 的 LUMO 较低。
