Synthesis and structure of zirconium-group 13 heterobimetallic compounds

Article abstract of DOI:10.1021/om00010a048

The reaction of main-group (B, Al, and Ga) alkoxides with zirconocene complexes of benzynes was used to prepare novel zirconium-group 13 heterobimetallic compounds [R₂E-(μ-OR′)(μ-1,2-aryl)Zr(η⁵-C ₅H₅)₂] [E = B, R = Et, R′ = Me, aryl = phenyl (1); E = B, R = Me, R′ = Et, aryl = phenyl (2); E = B, R = Et, R′ = Me, aryl = 3-methoxyphenyl (3); E = Al, R = Et, R′ = Et, aryl = phenyl (5); E = Ga, R = Me, R′ = Me, aryl = 3-methoxyphenyl (6)] and [(EtO)₂B(μ-1,2-naphthyl)Zr(η⁵-C₅H ₅)₂(OEt)] (4). Complexes 3 and 4 have been characterized by X-ray crystallography. Compound 3 contains a dative bond from an oxygen lone pair of the methoxy ligand on the zirconium to an acceptor p-orbital on the boron atom (¹¹B NMR; δ 8.26 ppm). In contrast, the weakly Lewis acidic boron center in 4 (¹¹B NMR; δ 29.7 ppm) does not show a bonding interaction between the alkoxy ligand on the zirconocene fragment and the boron center.