Bimetallic Organometallic Compounds of σ-<i>gem-</i>Diethynylethene (<i>gem</i>-DEE) Ligands: <i>trans-</i>Ru₂(DMBA)₄(<i>gem</i>-DEE)₂

Reported herein are the preparation and characterization of trans-Ru2(DMBA)4(gem-DEE)2 compounds 1a/1b (gem-DEE = σ-geminal-diethynylethene), the first examples of redox active metal complexes containing gem-DEE ligands. DFT calculations revealed a significant mixing between the π(DEE) and π*/π(Ru2) orbitals in both the HOMO and HOMO-1 of the model compound 1′.