Abstract
Terminal rare-earth-metal imide complexes Tp(tBu,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(tBu,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(tBu,Me)LnMe(HNAr(iPr)) which readily eliminate methane after being exposed to the Lewis base DMAP ([double bond, length as m-dash]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(tBu,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(tBu,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.