Lanthanide Amide Complexes Supported by the Bis-tris(pyrazolyl)borate Ligand Environment

Synthesis of primary lanthanide amides in the bis-hydrotris(1-pyrazolyl)borate ligand environment has been achieved. Salt metathesis of [Dy(Tp)(2)(OTf)] 1-Dy (OTf=CF3SO3) with K(N'') (N''=N(SiMe3)(2)) in toluene yielded the [bis(silyl)]amide [Dy(Tp)(2)(N'')] 2-Dy. Complexes 1-Ln and 2-Ln were both used to access primary lanthanide amides, where either metathesis of 1-Ln with K(NHArCF3) (ArCF3=C6H3(CF3)(2)-3,5) or protonolysis of 2-Ln with H2NArCF3 in toluene yielded [Ln(Tp)(2)(NHArCF3)] 3-Ln (Ln=Y, Dy). The synthesis of parent amides was also attempted, but the metathesis of 1-Y with NaNH2 yielded complicated reaction mixtures, but from which the dimeric parent amide [{Y(Tp)(2)(mu-NH2)}(2)] 4-Y and an 'ate'-salt [{Y(Tp)(2)(mu(2)-OTf)(mu(3)-OTf)Na(THF)(2)}(2)] 5-Y were isolated. Full characterisation data are presented for all complexes, including the structure determination.