Gallium Hydrides with a Radical-Anionic Ligand

The reaction of Cl<sub>2</sub>GaH with a sodium salt of the dpp-Bian radical-anion (dpp-Bian<sup>•–</sup>)Na (dpp-Bian = 1,2-bis­[(2,6-diisopropylphenyl)­imino]­acenaphthene) affords paramagnetic gallane (dpp-Bian<sup>•–</sup>)­Ga­(Cl)­H (<b>1</b>). Oxidation of (dpp-Bian<sup>2–</sup>)­Ga–Ga­(dpp-Bian<sup>2–</sup>) (<b>2</b>) with N<sub>2</sub>O results in the dimeric oxide (dpp-Bian<sup>•–</sup>)­Ga­(μ<sup>2</sup>-O)<sub>2</sub>Ga­(dpp-Bian<sup>•–</sup>) (<b>3</b>). A treatment of the oxide <b>3</b> with phenylsilane affords paramagnetic gallium hydrides (dpp-Bian<sup>•–</sup>)­GaH<sub>2</sub> (<b>4</b>) and (dpp-Bian<sup>•–</sup>)­Ga­{OSi­(Ph)­H<sub>2</sub>}H (<b>5</b>) depending on the reagent’s stoichiometry. The reaction of digallane <b>2</b> with benzaldehyde produces pinacolate (dpp-Bian<sup>•–</sup>)­Ga­(O<sub>2</sub>C<sub>2</sub>H<sub>2</sub>Ph<sub>2</sub>) (<b>6</b>). In the presence of PhSiH<sub>3</sub>, the reaction between digallane <b>2</b> and benzaldehyde (<b>2</b>: PhSiH<sub>3</sub>: PhC­(H)­O = 1:4:4) affords compound <b>4</b>. The newly prepared complexes <b>1</b>, <b>3</b>–<b>6</b> consist of a spin-labeled diimine ligand–dpp-Bian radical-anion. The presence of the ligand-localized unpaired electron allows the use of the ESR spectroscopy for characterization of the gallium hydrides reported. The molecular structures of compounds <b>1</b>, <b>3</b>–<b>6</b> have been determined by the single-crystal X-ray analysis.