Rare-Earth Metal Complexes with Terminal Imido Ligands

Imide complexes [(TptBu,Me)Y(=NC6H3Me2‐2,6)(DMAP)] and [(TptBu,Me)Lu{=NC6H3(CF3)2‐3,5}(DMAP)] were obtained by Lewis base induced methane elimination of the corresponding methyl/anilide complexes, which were synthesized from [(TptBu,Me)LuMe2] and [(TptBu,Me)YMe(GaMe4)], respectively. Terminal Ln=N bonding is evidenced by very short Ln–N distances [min. 1.993(5) Å] and almost linear Ln–N–C(aryl) bond angles. Lewis base induced methane elimination converts [(TptBu,Me)Ln(Me)(NHAr)] into mono‐rare‐earth metal imide complexes [(TptBu,Me)Ln(=NAr)(DMAP)]; terminal Ln=N bond formation is promoted by the superbulky ancillary TptBu,Me and corroborated by very short Ln–N bond lengths and almost linear Ln–N–C(aryl) bond angles (see structure; C gray, H white, N green, B pink, Lu magenta, F yellow green).