Synthesis and characterization of tantalum(V) metallaheterocycle (Me2N)3 and chloro-mixed-amide (Me2N)3Ta(Cl)[N(SiMe3)2]

Abstract

A new mixed-amido complex (Me2N)3Ta(Cl)[N(SiMe3)2] (1) was prepared from the reaction of (Me2N)3TaCl2 with 1 equiv. of LiN(SiMe3)2. The reactions of 1 with 1 equiv. of LiN(SiMe3)2 or (Me2N)3TaCl2 with 2 equiv. of LiN(SiMe3)2 gave (Me2N)3[Formula: see text] (2) with a four-membered metallaheterocyclic ring through γ-hydrogen abstraction. In the solid state, 1 adopts a distorted trigonal bipyramidal geometry with the -N(SiMe3)2 and -Cl ligands in the equatorial and axial positions, respectively. The X-ray structure of 2 reveals that it is in a distorted trigonal bipyramidal geometry with a planar metallaheterocyclic ring.Key words: tantalum, γ-hydrogen abstraction, C-H activation, amido complexes, metallacycle.