Synthesis, structural characterization, and reactivity of the ethyl substituted aluminum hydroxide and catalytic properties of its derivative

The ethyl substituted aluminum hydroxide LAlEt(OH) (2; L = HC[C(Me)N(Ar)]2; Ar = 2,6-iPr2C6H3) was prepared by the hydrolysis of LAlEt(Cl) (1) in the presence of a N-heterocyclic carbene. The reaction of 2 with Cp2ZrMe2 in toluene afforded LAlEt(μ-O)ZrMeCp2 (3) by evolution of methane, while the reaction of 2 with Cp3M in THF led to the intermolecular elimination of HCp and formation of LAlEt(μ-O)M(THF)Cp2 (M = Yb, 4; Er, 5; Dy, 6; Y, 7). Compounds 2 and 3 were characterized by single X-ray structural analysis. Compound 2 crystallizes in the orthorhombic space group P212121, while compound 3 crystallizes in space group Pnma. In both cases, the displacement of the Al and the γ-C atom out of the NCCN plane is observed in a boat conformation, but with converse direction. Furthermore, compound 3 was used as catalyst for ethylene polymerization.