Niobium and tantalum complexes containing 1,1-dialkylhydrazine-derived ligands

Niobium and tantalum complexes of the formula [M(NNMe2)Cl2(NH2NMe2)(TMEDA)]Cl · CH2Cl2, [M(NN(CH2)5)Cl2(NH2N(CH2)5)(TMEDA)]Cl · CH2Cl2 and [M(NN(CH2)5)Cl2(NH2N(CH2)5)2]Cl · [(CH2Cl2)(C6H14)0.5] were prepared by treatment of the corresponding metal pentachloride with a trimethylsilylhydrazine derivative in the presence of TMEDA or the parent hydrazine. The new complexes were characterized by NMR spectroscopy and X-ray crystallography.