We report on the synthesis of N-heterocyclic tetrylenes ligated by the NON-donor framework 4,5-bis(2,6-diisopropylphenyl-amino)-2,7-di-tert-butyl-9,9-dimethylxanthene. The molecular structures of the germylene (3), stannylene (4) and plumbylene (5) where determined by X-ray diffraction studies. Furthermore, we present quantum chemical studies on the σ-donor and π-acceptor properties of 3–5. Additionally, we report on the reactivity of the tetrylenes towards the transition metal carbonyls [Rh(CO)₂Cl]₂, [W(CO)₆] and [Ni(CO)₄]. The isolated complexes (6 and 7) show the differing reactivity of NHTs compared to NHCs. Instead of just forming the anticipated complex [(NON)Sn−Rh(CO)₂Cl], 4 inserts into the Rh−Cl bond to afford [(NON)Sn(Cl)Rh(CO)(C₆H₆)] (6, additional CO/C₆H₆ exchange) and [(NON)Sn(Cl)Rh₂(CO)₄Cl] (7). By avoiding halogenated transition metal precursors in order to prevent insertion reactions, germylene 3 shows “classical” coordination chemistry towards {Ni(CO)₃} forming the complex [(NON)Ge−Ni(CO)₃] (8).

中文翻译：

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非连接的 N-杂环丁三烯

我们报告了由非供体框架 4,5-双（2,6-二异丙基苯基-氨基）-2,7-二叔丁基-9,9-二甲基呫吨连接的N-杂环三甲苯的合成。通过 X 射线衍射研究确定了亚锗 ( 3 )、亚锡 ( 4 ) 和亚铅 ( 5 )的分子结构。此外，我们对3 – 5的 σ 供体和 π 受体特性进行了量子化学研究。此外，我们报告了四联苯对过渡金属羰基化合物 [Rh(CO) ₂ Cl] ₂、[W(CO) ₆ ] 和 [Ni(CO) ₄ ] 的反应性。孤立的复合物（图 6和7 ) 显示了 NHT 与 NHC 相比的不同反应性。而不是仅仅形成预期的复合物 [(NON)Sn-Rh(CO) ₂ Cl]，4插入到 Rh-Cl 键中以提供 [(NON)Sn(Cl)Rh(CO)(C ₆ H ₆ )] ( 6，额外的CO/C ₆ H ₆交换)和[(NON)Sn(Cl)Rh ₂ (CO) ₄ Cl] ( 7 )。通过避免卤化过渡金属前体以防止插入反应，锗烯3显示出对 {Ni(CO) ₃ } 形成复合物 [(NON)Ge-Ni(CO) ₃ ] 的“经典”配位化学（8）。