Interconversion among Dianionic, Anionic, and Neutral Compounds Bearing a Bond between Two Pentacoordinated Germanium Atoms

The
first dianionic compounds bearing a bond between two pentacoordinated
germanium atoms have been synthesized in a stable form as candidates
for a core unit to construct unprecedented structures in group 14
element chemistry. X-ray crystallographic analysis and computational
study indicated the single-bond character of the Ge–Ge bond.
They were reversibly converted to the anionic and neutral Ge–Ge-bonded
compounds while maintaining the coordination number of the germanium
atoms. The interconversion features changes in structures around the
germanium atoms, including changes from a staggered conformation of
the Ge–O bonds to a parallel conformation.