A Germapyramidane Switches Between 3D Cluster and 2D Cyclic Structures in Single‐Electron Steps

Reaction of the imidazolium-substituted diphosphete-diide, (IPr)2C2P2 (IDP), with GeCl2∙dioxane and KBArF24 [(BArF24)− = tetrakis[(3,5-trifluoromethyl)phenyl]borate)] afforded dicationic spherical-aromatic nido-cluster [Ge(η4-IDP)]2+ ([1]2+) (IPr 1,3-bis(2,6-diisopropylphenyl)imidazolium-2-ylidene). This complex is a rare heavy analogue elusive pyramidane [C(η4-C4H4)]. [1]2+ undergoes two reversible one-electron reductions which yield radical cation [2] •+ neutral Ge(II) species 3. Both 3 rearrange in solution forming 2D aromatic planar digermolide [4]2+ germole-diide 5, respectively. can be oxidized back to using AgSbF6. These redox-isomerizations correspond fundamental transformation 3D cluster into ring compound upon reduction vice versa. The mechanism these reactions was elucidated DFT calculations cyclic voltammetry experiments.