Organometallic chemistry of Ga+: Formation of an unusual gallium dimer in the coordination sphere of ruthenium

Abstract:

New insights into the distinct organometallic chemistry of the Ga ⁺ ion are presented. Ga⁺ reacts as a strong electrophile with the electron rich ligand trismethylene-methane (C(CH<inf>2</inf>) <inf>3</inf>^2-) 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*)<inf>3</inf>- [η³-(CH<inf>2</inf>)<inf>2</inf>C{CH<inf>2</inf>(μ-Ga)}]} <inf>2</inf>][(BAr^F)<inf>2</inf>] (4) (Cp* = C <inf>5</inf>Me<inf>5</inf>, [BAr^F] = [B{C<inf>6</inf>H <inf>3</inf>-(CF<inf>3</inf>)<inf>2</inf>}<inf>4</inf>]). 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⁺ as a ligand was found in the compound [Ru(PCy<inf>3</inf>)<inf>2</inf>(GaCp*)<inf>2</inf>(Ga)][BAr ^F] (6) (Cy = C<inf>6</inf>H<inf>11</inf>, cyclohexyl), the very short Ru-Ga bond length confirming the assumption that Ga⁺ represents a pure σ/π-accepting ligand in this case. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.

Año de publicación:

2008

Keywords:

• metal-metal interactions
• ruthenium
• Density functional calculations
• Low-valent ion
• Gallium

Fuente:

scopus

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