The synthesis of alkyl niobocene imido complexes and the X-ray crystal structure of [Nb(O)Cp2Me] (Cp=η5-C5H5)

The following new niobium imido complexes containing alkyl ligands have been prepared and characterised: [Nb(NBut)Cp2Et] (1), [Nb(NBut)Cp2(CH2SiMe3)] (2), [Nb(NAr)Cp2Me] (3), [Nb(NAr)Cp2Et] (4), [Nb(NAr)Cp2(CH2Ph)] (5), [Nb(NAr)Cp2(CH2SiMe3)] (6), [Nb(NAr)Cp2(CH2CHCH2)] (7) (Cp=η5-C5H5, Ar=C6H4Me-4). The synthetic pathway to these complexes is by the reaction of the appropriate magnesium reagent MgRCl with the metallocene complexes [Nb(NBut)Cp2Cl] or [Nb(NAr)Cp2Cl]. The hydrolysis of 3 gave the oxo-alkyl complex [Nb(O)Cp2Me] (8). The molecular structure of 8 has been determined by X-ray diffraction studies.