Reactivity Study of a Pyridyl-1-azaallylgermanium(I) Dimer: Synthesis of Heavier Ether and Ester Analogues of Germanium

GeI-GeI Coupling Reaction Induced by a Mixture of CoBr2 and a Seven-Membered N-Heterocyclic Carbene

A new digermylene has been synthesized through the reaction of a six-membered cyclic radical germylene precursor with a mixture of CoBr₂ and a seven-membered N-heterocyclic carbene. The density functional theory simulation on the geometry of the digermylene agrees well with the experimental X-ray diffraction result. The digermylene possesses the shortest Ge^I-Ge^I bond [2.4853(6) Å] compared to the known singly bonded analogues, which can be attributed to σ → π* conjugation. In addition, it is revealed that a stable dative bond cannot form for the reductive radical germylene with the oxidative metal centers.

Synthesis and Characterization of an Eclipsed Digermylene as a Building Block to Construct a Cyclic Octagermylene

The preparation of an unprecedented Ge^I -Ge^I bonded digermylene [K₂ {Ge₂ (μ-κ² :η² :η⁴ -2,6-(2,6-ⁱ Pr₂ C₆ H₃ -N)₂ -4-CH₃ C₅ H₂ N)₂ }] in an eclipsed conformation stabilized by two bridging diamidopyridyl ligands is presented. Although it exhibits an eclipsed conformation, the Ge-Ge bond length is 2.5168(6) Å, which is shorter than those in the trans-bent and gauche digermylenes. In combination with two pendant amido groups, the Ge^I₂ motif is employed as a building block to assemble the first example of octagermylene [Ge₄ (μ-κ² :κ¹ -2,6-(2,6-ⁱ Pr₂ C₆ H₃ -N)₂ -4-CH₃ C₅ H₂ N)₂ ]₂ showing a cyclic configuration and containing three distinct types of Ge^I -Ge^I bonds.