A Tetra-amido-Protected Ge-Spiropentadiene.

The first isolable Ge-spiropentadiene was synthesized via the reduction of (PrSi)NGeCl () with potassium. The crystal structure of reveals a spirocyclic Ge skeleton containing two Ge-Ge double bonds (avg. 2.34 Å), which are fettered in two Ge rings with a dihedral angle of 70.193°. The DFT calculations and orbital analysis show that the σ-delocalization of the Ge skeleton and the 2π-delocalized aromatic Ge rings enhance the stability of molecule .