Organometallic Chemistry of Ga⁺: Formation of an Unusual Gallium Dimer in the Coordination Sphere of Ruthenium

<jats:title>Abstract</jats:title><jats:p>New insights into the distinct organometallic chemistry of the Ga<jats:sup>+</jats:sup>ion are presented. Ga<jats:sup>+</jats:sup>reacts as a strong electrophile with the electron rich ligand trismethylene‐methane (C(CH<jats:sub>2</jats:sub>)<jats:sub>3</jats:sub><jats:sup>2−</jats:sup>) attached at Ru by insertion into a RuC bond. The resulting “gallamethylallyl” ligand behaves like strong nucleophile similar to known monovalent GaR species. This donor property leads to the dimeric structure of the product [{Ru(GaCp*)<jats:sub>3</jats:sub>[η<jats:sup>3</jats:sup>‐(CH<jats:sub>2</jats:sub>)<jats:sub>2</jats:sub>C{CH<jats:sub>2</jats:sub>(μ‐Ga)}]}<jats:sub>2</jats:sub>][(BAr<jats:sup>F</jats:sup>)<jats:sub>2</jats:sub>] (<jats:bold>4</jats:bold>) (Cp*=C<jats:sub>5</jats:sub>Me<jats:sub>5</jats:sub>, [BAr<jats:sup>F</jats:sup>]=[B{C<jats:sub>6</jats:sub>H<jats:sub>3</jats:sub>(CF<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>}<jats:sub>4</jats:sub>]). Very unexpectedly, the two gallium ligands in this dimer are found in close vicinity to each other with a distance in the range of GaGa bonds. Indeed, AIM calculations confirm a weak attractive closed shell GaGa interaction. Finally, a novel example of a complex with substituent‐free Ga<jats:sup>+</jats:sup>as a ligand was found in the compound [Ru(PCy<jats:sub>3</jats:sub>)<jats:sub>2</jats:sub>(GaCp*)<jats:sub>2</jats:sub>(Ga)][BAr<jats:sup>F</jats:sup>] (<jats:bold>6</jats:bold>) (Cy=C<jats:sub>6</jats:sub>H<jats:sub>11</jats:sub>, cyclohexyl), the very short RuGa bond length confirming the assumption that Ga<jats:sup>+</jats:sup>represents a pure σ/π‐accepting ligand in this case.</jats:p>