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.