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 [R(2)E-(mu-OR')(mu-1,2-aryl)Zr(eta(5)-C5H5)(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)(2)B(mu-1,2-naphthyl)Zr(eta(5)-C5H5)(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 (B-11 NMR; delta 8.26 ppm). In contrast, the weakly Lewis acidic boron center in 4 (B-11 NMR; delta 29.7 ppm) does not show a bonding interaction between the alkoxy ligand on the zirconocene fragment and the boron center.
“Synthesis and Structure of Zirconium Group-13 Heterobimetallic Compounds”, Organometallics, 1995, 14(10), 4799-4807.