The treatment of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with one equivalent of AlCl(3) and three equivalents of sodium in toluene at 110 °C produced a stable dialane, (dpp-bian)Al-Al(dpp-bian) (1). The reaction of compound 1 with pyridine gave Lewis-acid-base adduct (dpp-bian)(Py)Al-Al(Py)(dpp-bian) (2). Acetylene and phenylacetylene reacted with compound 1 to give cycloaddition products [dpp-bian(R(1)R(2))]Al-Al[(R(2)R(1))dpp-bian] (3: R(1)=R(2)=CH; 4: R(1)=CH, R(2)=CPh). These addition reactions occur across Al-N-C moieties and result in the formation of new C-C and C-Al bonds. At elevated temperatures, compound 4 rearranges into complex 5, which consists of a radical-anionic dpp-bian ligand and two bridging alken-1,2-diyl moieties, (dpp-bian)Al(HCCPh)(2)Al(dpp-bian). This transformation is accompanied by cleavage of the dpp-bian-ligand-alkyne C-C bond, as well as of the Al-Al bond. In contrast to its analogous gallium complex, compound 1 is reactive towards internal alkynes. In the reaction of compound 1 with PhC≡CMe, besides symmetrical addition product [dpp-bian(R(1)R(2))]Al-Al[(R(2)R(1))dpp-bian] (R(1)=CMe, R(2)=CPh; 6), monoadduct [dpp-bian(R(1)R(2))]Al-Al(dpp-bian) (R(1)=CMe, R(2)=CPh; 7) was also isolated. Complexes 1-7 were characterized by IR, (1)H NMR (1-4), and electronic absorption spectroscopy (3-5); the molecular structures of compounds 1-7 were determined by single-crystal X-ray diffraction.

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The reaction of ClGaH 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)Ga-Ga(dpp-Bian) (2) with NO results in the dimeric oxide (dpp-Bian)Ga(μ-O)Ga(dpp-Bian) (3). A treatment of the oxide 3 with phenylsilane affords paramagnetic gallium hydrides (dpp-Bian)GaH (4) and (dpp-Bian)Ga{OSi(Ph)H}H (5) depending on the reagent's stoichiometry. The reaction of digallane 2 with benzaldehyde produces pinacolate (dpp-Bian)Ga(OCHPh) (6). In the presence of PhSiH, the reaction between digallane 2 and benzaldehyde (2: PhSiH: 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.

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The reactions of H2AlCl with [(dpp-Bian)­Na­(Et2O)n] and [(ArBIG-Bian)­Na­(THF)] produce respective aluminum hydrides supported by radical-anionic 1,2-bis­(arylimino)­acenaphthene ligands, [(dpp-Bian)­AlH2] (1) and [(ArBIG-Bian)­AlH2(THF)] (2) (dpp-Bian = 1,2-bis­[(2,6-diisopropylphenyl)­imino]­acenaphthene); ArBIG-Bian = 1,2-bis­[(2,6-dibenzhydryl-4-methylphenyl)­imino]­acenaphthene). The reaction of 1 with CO2 proceeds with reduction of both CO bonds and results in diolate [{(dpp-Bian)­Al­(μ-O2CH2)}2] (3). Complex 2 reacts with CO2 to carbonate [{(ArBIG-Bian)­Al­(μ-OCH2OCO2)}2] (4) that is a result of the insertion of CO2 into the Al–O bond in diolate species formed initially. Aluminum monohydrides [(dpp-Bian)­AlH­(X)] (X = Cl, 5; Me, 6) react with CO2 to form respective alumoxanes [{(dpp-Bian)­AlX}2(μ-O)] (X = Cl, 7 and X = Me, 8). Compounds 1–4, 7, and 8 have been characterized by ESR and IR spectroscopy, and their molecular structures have been determined by single-crystal X-ray analysis.

The reaction of (dpp-bian)AlEt(EtO) (1) (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with 4,4'-dimethoxybenzophenone leads to the replacement of EtO with the ketone resulting complex (dpp-bian)AlEt[O[double bond, length as m-dash]C(4-MeOCH)] (2). The reaction of compound 1 with 2,6-di-tert-butyl-4-methylphenol (1 : 1) or PhNH (1 : 1) affords the addition products [dpp-bian(H)]AlEt[O(2,6-tBu-4-MeCH)] (3) and [dpp-bian(H)]AlEt(NPh) (4) correspondingly. Treatment of complex 1 with 0.5 molar equivalents of HO gives ethylalumoxane {[dpp-bian(H)]AlEt}(μ-O) (5). Newly prepared complexes 2-5 have been characterized by NMR and IR spectroscopy, and the molecular structures of 2, 3, and 5 have been determined by single crystal X-ray analysis.

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