Crystalline di- or trianionic metal (Al, Sm) β-diketiminates

摘要

The new [Al(L~(Tol))Br_2] (1) and the known [Al(L ~(Ph))Me_2] (2) were prepared as potential precursors to more novel aluminium compounds. In the event, only the latter was effective. Thus 2 and two equivalents of potassium was the source of [{Al(L~(Ph))Me _2K_2(OEt_2)}_2] (3). The complexes [{KSm(L~(Ph))_2}_2] (4), [Sm_2(L Dph)_3] (5) and [Sm(L~(Tol,Ad))(L ~(Tol,Ad)-H)] (6) were obtained from SmI_2 and two equivalents of the appropriate potassium β-diketiminate [L~(Ph) or L ~(Tol) or L~(Dph) = {N(SiMe_3)C(Ar)}_2CH, Ar = Ph or C_6H_4Me-4 or C_6H_4Ph-4; L~(Tol,Ad) = N(SiMe_3)C(C_6H_4Me-4)C(H) C(Ad)NSiMe_3, L~(Tol,Ad)-H = N(SiMe_3)C(C _6H_4Me-4)C(H)C(Ad)NSiMe_2CH_2, Ad = 1-adamantyl]. Crystalline complexes 3-6 were isolated in very low (4, 5) or satisfactory (3, 6) yield and characterised by X-ray diffraction. From comparisons of the M-N, N-C, C-C and C-C_(Ar) bond lengths with suitable standards, complexes 3-5 are assigned as containing Al~(3+)/(L ~(Ph)3-) for 3, Sm~(3+)/(L~(Ph)) -/(L~(Ph)3-) for 4, and {Sm~(3+)} _2/(L~(Dph))-/(L~(Dph)2-)/ (L~(Dph)3-) for 5. Complex 6 is best formulated as a Sm ~(3+) compound with one "normal" (L~(Tol,Ad) -) and one deprotonated (L~(Tol,Ad)-H)~(2-) ligand.