Dicationic 1-Germa and 1-Stannavinylidenes: Synthesis, Structure, and Reactivity
Yuankai Li, Huan Mu, Zhuchunguang Liu, Zhu Qi, Jiliang Zhou, Zhaowen Dong
Abstract
High Resolution Image Download MS PowerPoint Slide The synthesis of heteronuclear vinylidene analogues containing heavier group 14 elements (R 2 C═E:, E = Si, Ge, Sn) has been a challenging task due to their inherent instability. In this study, we report the synthesis of dicationic 1-germavinylidene ( 3Ge ) and 1-stannavinylidene ( 3Sn ) by using sym-bis(2-pyridyl)-tetraphenylcarbodiphosphorane (CDPPy 2 ) as a donor ligand. Both 3Ge and 3Sn have been characterized by single-crystal X-ray diffraction analysis, NMR spectroscopy, and high-resolution mass spectrometry. The structural analysis, supported by the results of theoretical calculations, confirms that 3Ge and 3Sn feature a polarized C═E double bond and a lone pair of electrons located at the E atom (E = Ge and Sn). The reactions of 3Ge with IDippMCl (M = Cu, Ag, Au) give the M–Cl bond addition products. Mechanistic studies on the activation of the Au–Cl bond by 3Ge demonstrate its ambiphilicity. This work represents an example of the utilization of a carbone ligand as both an σ and π donor for the synthesis of heavier heteronuclear vinylidene analogues.