An unprecedented aluminum hydroxide LAlMe(OH) (5; L = HC[(CMe)(2,6-iPr2C6H3N)]2) has been prepared by the hydrolysis of LAlMeCl (4). For the preparation of 5, the reagents of KOH, water, and KH, as well as the two-phase ammonia/toluene system, were used. Further reactions of 5 with Cp2ZrMe2 (8) and Cp2ZrHCl in toluene lead to the intermolecular elimination of CH4 and H2 and the formation of mu-O-bridged dinuclear aluminum and zirconium complexes [LAlMe(mu-O)ZrMeCp2] (6) and [LAlMe(mu-O)ZrClCp2] (7), respectively, in high yields. The crystal structure reveals that 5 is a monomer with terminal OH and Me groups. The X-ray structure analysis shows that 6 and 7 contain a bent Al-(mu-O)-Zr core with terminal Al-Me and Zr-Me or Zr-Cl arrangements. The methylalumoxane (MAO)-activated compounds 6 and 7 exhibit high catalytic activity for the polymerization of ethylene. Under comparable polymerization conditions, the MAO/6 and MAO/7 catalyst systems show considerably higher activity and much lower MAO:catalyst ratios than that of MAO/8.

The compound (Nacnac)Ni(μ-Br)2Li(THF)2 (Nacnac = (HC(CMeNC6H3(i-Pr)2)2) was reduced by reaction with K/Na alloy in toluene. The resulting product [((Nacnac)Ni)2(μ-η3:η3-C6H5Me)] (1) was characterized and is best described as a Ni(II) species in which electron transfer from Ni to toluene has occurred. This compound reacts with a variety of donors to give Ni(I) complexes. For example, compound 1 reacts with phosphines, nitriles, acetylenes, olefins, and ketones to give the paramagnetic complexes (Nacnac)Ni(PCy3) (2), (Nacnac)Ni(Ph2PCH2PPh2) (3), (Nacnac)Ni(NCPh) (4), (Nacnac)Ni(η 2-PhCCPh) (5), (Nacnac)Ni(η 2-Me3SiCCSiMe3)(6), (Nacnac)Ni(η 2-H2CCPh2) (7), and (Nacnac)Ni(OCPh2) (8). In the related reaction of 1 with dimethylfulvene, electron transfer from metal to ligand is evidenced by the formation of the dimetallic species [((Nacnac)Ni(η 3:η 3-C5H4CMe2))2] (9). The crystal structures of 1−9 are reported, and the bonding and reactivity of these products are discussed.

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