The synthesis of alkyl niobocene imido complexes and the X-ray crystal structure of [Nb(O)Cp 2Me] (Cp=η 5-C 5H 5)

Abstract

The following new niobium imido complexes containing alkyl ligands have been prepared and characterised: [Nb(NBu t )Cp 2Et] ( 1), [Nb(NBu t )Cp 2(CH 2SiMe 3)] ( 2), [Nb(NAr)Cp 2Me] ( 3), [Nb(NAr)Cp 2Et] ( 4), [Nb(NAr)Cp 2(CH 2Ph)] ( 5), [Nb(NAr)Cp 2(CH 2SiMe 3)] ( 6), [Nb(NAr)Cp 2(CH 2CHCH 2)] ( 7) (Cp=η 5-C 5H 5, Ar=C 6H 4Me-4). The synthetic pathway to these complexes is by the reaction of the appropriate magnesium reagent MgRCl with the metallocene complexes [Nb(NBu t )Cp 2Cl] or [Nb(NAr)Cp 2Cl]. The hydrolysis of 3 gave the oxo-alkyl complex [Nb(O)Cp 2Me] ( 8). The molecular structure of 8 has been determined by X-ray diffraction studies.