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.