Synthesis of tantalum and niobium complexes that contain the diamidoamine ligand, [(3,4,5-F3C6H2NCH2CH2)2NMe]2−, and the triamidoamine ligand, [(3,5-Cl2C6H3NCH2CH2)3N]3−

Several niobium and tantalum compounds were prepared that contain either the diamidoamine ligand, [(3,4,5-F3C6H2NCH2CH2)2NMe]2−, or the triamidoamine ligand, [(3,5-Cl2C6H3NCH2CH2)3N]3−. An example of the former is [(3,4,5-F3C6H2NCH2CH2)2NMe]Ta(CHSiMe3)(CH2SiMe3), which is prepared by treating [(3,4,5-F3C6H2NCH2CH2)2NMe]TaCl3 with 3 equiv. of Me3SiCH2MgCl.