Spirobis(pentagerma[1.1.1]propellane): A Stable Tetraradicaloid

In this contribution, we report a spirobis­(pentagerma[1.1.1]­propellane) derivative as a novel type of molecular architecture in cluster chemistry that features two spiro-fused [1.1.1]­propellane units and represents a stable tetraradicaloid species. The crucial issue of the nature of the interaction between the germanium bridgeheads was probed computationally, revealing weak bonding interactions between the formally unpaired electrons.