[(μ2-H)(η2-Ge4)ZnPh2]3−, an edge-on protonated E4 cluster establishing the first three-center two-electron Ge–H–Ge bond

Abstract

The first example of a protonated and a rare example of a metal complex of the tetrahedral tetrel cluster anion [Ge₄]⁴⁻ was obtained from a solution of K₆Rb₆Ge₁₇ in liquid ammonia in the presence of ZnPh₂ and [18]crown-6. In [K([18]crown-6)][Rb([18]crown-6)]₂[HGe₄ZnPh₂]·8NH₃ (1) one ZnPh₂ molecule and one H atom are bound to opposite, significantly elongated edges of a distorted Ge₄ tetrahedron. DFT calculations confirm the experimentally found interatomic distances and reveal a structural proof of a three-center two-electron Ge–H–Ge bond.