Gallium Hydrides with a Radical-Anionic Ligand

Abstract

The reaction of Cl 2 GaH with a sodium salt of the dpp-Bian radical-anion (dpp-Bian •– )Na (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) affords paramagnetic gallane (dpp-Bian •– )Ga(Cl)H ( 1 ). Oxidation of (dpp-Bian 2– )Ga–Ga(dpp-Bian 2– ) ( 2 ) with N 2 O results in the dimeric oxide (dpp-Bian •– )Ga(μ 2 -O) 2 Ga(dpp-Bian •– ) ( 3 ). A treatment of the oxide 3 with phenylsilane affords paramagnetic gallium hydrides (dpp-Bian •– )GaH 2 ( 4 ) and (dpp-Bian •– )Ga{OSi(Ph)H 2 }H ( 5 ) depending on the reagent’s stoichiometry. The reaction of digallane 2 with benzaldehyde produces pinacolate (dpp-Bian •– )Ga(O 2 C 2 H 2 Ph 2 ) ( 6 ). In the presence of PhSiH 3, the reaction between digallane 2 and benzaldehyde ( 2: PhSiH 3: PhC(H)O = 1:4:4) affords compound 4 . The newly prepared complexes 1, 3 – 6 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 1, 3 – 6 have been determined by the single-crystal X-ray analysis.