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

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(2)K(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 beta-diketiminate [L(Ph) or L(Tol) or L(Dph) = {N(SiMe(3))C(Ar)}(2)CH, Ar = Ph or C(6)H(4)Me-4 or C(6)H(4)Ph-4; L(Tol,Ad) = N(SiMe(3))C(C(6)H(4)Me-4)C(H)C(Ad)NSiMe(3), L(Tol,Ad)-H = N(SiMe(3))C(C(6)H(4)Me-4)C(H)C(Ad)NSiMe(2)CH(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.