Synthesis, characterisation and reactions of 1,3-bis(trimethylsilyl)-1-aza-allyl-lanthanide complexes; X-ray structures of [Sm(LL′)2I(thf)], [Yb(LL′)2] and [RN=C(But) CH(R)]2 (thf = tetrahydrofuran, LL′ = η3-N(R)C(But) CHR, R=SiMe3)1

Article abstract of DOI:10.1016/S0022-328X(96)06879-9

Several lanthanide(II) and lanthanide(III) complexes of formula [Ln(LL′)₂X(thf)_n] (LL′ = η³-N(R)C(Bu^t)CHR, R = SiMe₃; X = Cl, n = 1 and Ln = Ce 1 or Nd 2; or X = I, n = 1 and Ln = Sm 3; or X = I, n = 0 and Ln = Yb 4), [Sm(LL′)₂(thf)] 5 and [Yb(LL′)₂] 6 have been synthesised by the reaction of the appropriate lanthanide(II) or lanthanide(III) halide with two equivalents of 1,3-bis(trimethylsilyl)-1-aza-allyl-potassium [K(LL′)]_n. Oxidation of 6 with Ag(OTf) afforded [Yb(LL′)₂(OTf)] 7 (Tf = SO₂CF₃). The reaction of 6 with half an equivalent of I₂ yielded as the main oxidative product 4 but also led to ligand coupling, forming [RN=C(Bu^t)CH(R)]₂ 8, which was also prepared by the reaction of [K(LL′)]_n with I₂. Treatment of 6 with two equivalents of PhCN yielded the previously known β-diketiminate [Yb(L′L″)₂] [L′L″ = N(R)C(Ph)C(H)C(Bu^t)NR]. Complexes 1-8 were identified by C, H and N elemental analysis, multinuclear (¹H, ¹³C, ²⁹Si{¹H}, ¹⁷Yb or ¹⁹F) NMR and mass spectra, of which 3, 6 and 8 were additionally characterised by single crystal X-ray diffraction.