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

• Published in: European journal of inorganic chemistry 2024-04, Vol.27 (11), p.n/a
• Main Authors: Chowdhury, Tajrian, Wilson, Claire, Maichle‐Mössmer, Cäcilia, Anwander, Reiner, Farnaby, Joy H.
• Format: Article
• Language: English
• Subjects: Amides; Dysprosium; heteroleptic; lanthanides; Ligands; Metathesis; pyrazoles; Synthesis; Toluene
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.202300731

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(μ‐NH2)}2] 4‐Y and an ‘ate’‐salt [{Y(Tp)2(μ2‐OTf)(μ3‐OTf)Na(THF)2}2] 5‐Y were isolated. Full characterisation data are presented for all complexes, including the structure determination. The specific synthetic conditions to successfully access primary lanthanide amides in the bis‐hydrotris(1‐pyrazolyl)borate ligand environment [Ln(Tp)2(NHArCF3)] 3‐Ln (Ln=Y, Dy; ArCF3=C6H3(CF3)2‐3,5) are reported by either metathesis of [Ln(Tp)2(OTf)] 1‐Ln (OTf=CF3SO3) with K(NHArCF3) or protonolysis of [Ln(Tp)2(N′′)] 2‐Ln (N′′=N(SiMe3)2) with H2NArCF3 in toluene.