Spontaneous Decomposition of an Extraordinarily Twisted and Trans‐Bent Fully‐Phosphanyl‐Substituted Digermene to an Unusual Ge(I) Cluster

Ditetrelenes R(2)E=ER(2) (E=Si, Ge, Sn, Pb) substituted by multiple N/P/O/S‐donor groups are extremely rare due to their propensity to disaggregate into their tetrylene monomers R(2)E. We report the synthesis of the first fully phosphanyl‐substituted digermene {(Mes)(2)P}(2)Ge=Ge{P(Mes)(2)}(2) (3, Mes=2,4,6‐Me(3)C(6)H(2)), which adopts a highly unusual structure in the solid state, that is both strongly trans‐bent and highly twisted. Variable‐temperature (31)P{(1)H} NMR spectroscopy suggests that 3 persists in solution, but is subject to a dynamic equilibrium between two conformations, which have different geometries about the Ge=Ge bond (twisted/non‐twisted) due to a difference in the nature of their π‐stacking interactions. Compound 3 undergoes unprecedented, spontaneous decomposition in solution to give a unique Ge(I) cluster {(Mes)(2)P}(4)Ge(4)⋅5 CyMe (7).