A Non-innocent Ligand Supported Germylene and Its Diverse Reactions

To expand the reactivity scope of divalent germanium, an α-iminopyridine supported dicoordinate germanium complex (2) was prepared from deamination of the corresponding pyridine-coordinated diamido germylene (1). The non-innocent ligand supported germanium compound can be viewed as a benzo-fused N-heterocyclic germylene or a neutral α-iminopyridine-coordinated germylone. While the Ge-ligand cooperation observed in the reaction of 2 with HCl and BCl3 confirms the presence of a vacant p orbital at the Ge­(II) atom, the readily transferring of a ligand from 2 to MCl2 (M = Ge, Sn) with the extrusion of metallic germanium reflects the electron richness of the central Ge(0) atom. The germylone character of 2 was further verified via four-electron oxidation with 2 equiv of tetra-chloro-o-benzoquinone to give the corresponding six-coordinated germanium­(IV) adduct.为拓展二价锗（divalent germanium）的反应活性范围，我们通过相应吡啶配位的二酰胺锗烯（pyridine-coordinated diamido germylene）(1)的脱氨反应，制备得到一种α-亚胺吡啶（α-iminopyridine）配位的双配位锗配合物(2)。 该非无辜配体（non-innocent ligand）配位的锗基化合物，可被视为苯并稠合氮杂环锗烯（benzo-fused N-heterocyclic germylene），或是中性α-亚胺吡啶配位的锗炔（germylone）。尽管在配合物2与氯化氢（HCl）、三氯化硼（BCl3）的反应中观察到的锗-配体协同作用，证实了二价锗原子上空缺p轨道的存在，但配体从2快速转移至MCl2（M=Ge、Sn）并伴随金属锗脱除的过程，却反映出中心零价锗原子的富电子特性。 通过使用2当量的四氯邻苯醌（tetra-chloro-o-benzoquinone）进行四电子氧化，得到相应的六配位锗(IV)加合物，进一步验证了配合物2的锗炔特性。