A planar per-borylated digermene

A tetraboryl digermene synthesized by the reaction between a dianionic digermanide nucleophile and a boron halide electrophile is dimeric both in the solid state and in hydrocarbon solution. It features both a planar 'alkene-like' geometry for the Ge2B4 core, and an exceptionally short Ge00000000000000000000000000000000111111110000000011111111000000000000000000000000Ge double bond. These structural features are consistent with the known electronic properties of the boryl group, and with lowest energy (in silico) fragmentation into two triplet bis(boryl)germylene fragments. A tetraboryl digermene features both a planar 'alkene-like' geometry for the Ge2B4 core, and an exceptionally short GeGe double bond, consistent with lowest energy (in silico) fragmentation into two triplet bis(boryl)germylene fragments.