Synthesis and Thermolysis of Ylidyl‐Substituted Stannylenes

Low-valent group 14 compounds, i.e., tetrylenes, have been subject of research since the 1970s and are still in the focus of interest. Herein, we report on the synthesis of the dimeric amido(ylidyl)stannylene [Ph₃PCH{SnN(SiMe₃)₂}]₂ (1) synthesized from readily available starting materials. X-ray diffraction analysis shows that the compound features a heterocyclic Sn₂C₂ core structure substituted by bis(trimethylsilyl)amido ligands. Addition of gallium trichloride led to a ligand exchange of the amide to chloride. The dimeric chlorostannylene [Ph₃PCH{SnCl}]₂ (2) was found to be insoluble in organic solvents but could potentially serve as a precursor to synthesize further ylidyl-substituted stannylenes with the identical structural motive. Thermal treating of 1 led to ortho-metalation of one Ph substituent under concomitant elimination of HN(SiMe₃)₂ providing the dimeric, ortho-metalated aryl(ylidyl)stannylene [Ph₂PCH(μ-C₆H₄)Sn]₂ (V), which has already been described before in the literature. As a side product, we also obtained a mixture of a Sn₄C₄ heterocubane and an oligomer featuring a Sn₃C₄ core structure. Quantum chemical calculations were performed to analyze the tin–carbon interaction in the stannylenes.