A NOVEL CLASS OF ORGANOMETALLIC COMPLEXES - 1,1-BIMETALLICS OF BORON AND ZIRCONIUM

Representatives of a new class of 1,1-bimetallics of boron and zirconi um, l)[1-(1,3,2-dioxaborinane-2-yl)hexyl]zirconium(IV) (1) and xaborol ane-2-yl)-3,3-dimethylbutenyl]zirconium(IV) (2) were prepared by hydro zirconation of the corresponding unsaturated boronates. X-ray analysis and NMR studies confirmed the configuration of the four-coordinated z irconium complexes with two cyclopentadienyl rings, Cl and Csp(3) or C sp(2) as four ligands, forming almost regular tetrahedrons. There are no intra- or intermolecular interactions between zirconium and boron o r oxygen atoms. The heterocyclic rings - 1,3,2-dioxaborinane and 1,3,2 -dioxaborolane - adopt the envelope conformations. The planar part, C- O-B-O, of the five-membered boracycle and the alkene moiety of 2 are n ot conjugated.