Terminal dysprosium and holmium organoimides

• Published in: Chemical science (Cambridge) Vol. 15; no. 1; pp. 3562 - 357
• Main Authors: Rieser, Theresa E, Schädle, Dorothea, Maichle-Mössmer, Cäcilia, Anwander, Reiner
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 06.03.2024; The Royal Society of Chemistry
• Subjects: Aniline; Carbon dioxide; Chemistry; Coordination compounds; Dysprosium; Holmium; Imides; Lewis acid; Lewis base; Methane; Rare earth elements
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d3sc06584g

Terminal rare-earth-metal imide complexes Tp t Bu,Me Ln(NC 6 H 3 iPr 2 -2,6)(dmap) of the mid-late rare-earth elements dysprosium and holmium were synthesized via double methane elimination of Lewis acid stabilized dialkyl precursors Tp t Bu,Me LnMe(GaMe 4 ) with primary aniline derivative H 2 NC 6 H 3 iPr 2 -2,6 (H 2 NAr iPr ). Exploiting the weaker Ln-CH 3 [GaMe 3 ] interaction compared to the aluminium congener, addition of the aniline derivative leads to the mixed methyl/anilido species Tp t Bu,Me LnMe(HNAr iPr ) which readily eliminate methane after being exposed to the Lewis base DMAP (&z.dbd; N , N -dimethyl-4-aminopyridine). Under the same conditions, [AlMe 3 ]-stabilized dimethyl rare-earth-metal complexes transform immediately to Lewis acid bridged imides Tp t Bu,Me Ln(μ 2 -NC 6 H 3 Me 2 -2,6)(μ 2 -Me)AlMe 2 (Ln = Dy, Ho). DMAP/THF donor exchange is accomplished by treatment of Tp t Bu,Me Ln(NC 6 H 3 iPr 2 -2,6)(dmap) with 9-BBN in THF while the terminal imides readily insert carbon dioxide to afford carbamate complexes. Tp t Bu,Me Ln(&z.dbd;NC 6 H 3 iPr 2 -2,6)(dmap) (Ln = Dy, Ho) display the first terminal imides of open-shell mid-sized lanthanides, exhibiting reactivity similar to Chen's seminal scandium terminal imide.