Chalcogeno[bis(phosphaalkenyl)] Germanium and Tin Compounds

The first diphosphaalkenylstannylene stabilized through complexation with a carbene NHC–Sn­[C­(Cl)PMes*]2 1 (Mes* = 2,4,6-tri-tert-butylphenyl; NHC = :C­{N­(iPr)­C­(Me)}2) was isolated and fully characterized including single crystal X-ray diffraction analysis. Its reaction with elemental sulfur rapidly gives the cyclic Sn2S2 (dithiadistannetanne) derivative 3, presumably formed by dimerization of a stannathione intermediate. By contrast, its germanium analogue NHC–Ge­[C­(Cl)PMes*]2 7 leads to the corresponding monomeric germathione 4 and germaselenone 5. The germaselenone was more stable than the germathione and could be structurally characterized. An unusual thermal cyclization reaction of the last one occurs with an excess of selenium to give the Ge2Se3 (triselenadigermolane) ring derivative 6.首例通过与氮杂环卡宾（NHC）络合稳定的二磷烯基亚锡（diphosphaalkenylstannylene）配合物NHC–Sn[C(Cl)=PMes*]₂ 1（其中Mes*为2,4,6-三叔丁基苯基（2,4,6-tri-tert-butylphenyl），NHC为:C{N(iPr)C(Me)}₂）已被分离并完成全面表征，表征手段涵盖单晶X射线衍射分析。该配合物与单质硫快速反应，生成环状二硫二锡杂环丁烷（dithiadistannetanne）衍生物3，其生成途径推测为硫代锡烯（stannathione）中间体的二聚反应。与之相对，其锗类似物NHC–Ge[C(Cl)=PMes*]₂ 7则生成相应的单核硫代锗烯（germathione）4与硒代锗酮（germaselenone）5。硒代锗酮的稳定性优于硫代锗烯，且可通过结构表征确定其分子构型。硫代锗烯4与过量硒发生罕见的热环化反应，生成Ge₂Se₃（三硒二锗杂环戊烷，triselenadigermolane）环衍生物6。