Aluminum and Yttrium Complexes of an Unsymmetrical Mixed Fluorous Alkoxy/Phenoxy-Diimino Ligand: Synthesis, Structure, and Ring-Opening Polymerization Catalysis

作者：Alaaeddine Ali; Thomas Christophe M; Roisnel Thierry; Carpentier Jean Francois^*

来源：Organometallics, 2009, 28(5): 1469-1475.

DOI：10.1021/om8010273

The coordination chemistry of the new unsymmetrical Schiff base ligand {(3,5-tBu(2)-1-OC(6)H(4))CH=N(trans-1,2-cyclo-C(6)H(10))N=C(Me)CH(2)C(CF(3))(2)O}(2-) ({(Ar)ON(Cy)NO(CF3)}(2-)) onto Al(III) and Y(III) centers has been studied. Pro-ligand {(Ar)ON(Cy)NO(CF3)}H(2) (1) reacts with AlMe2Cl, Al(OiPr)(3) and Y(N(SiHMe(2))(2))(3)center dot(THF)(2) to give the corresponding complexes {(Ar)ON(Cy)NO(CF3)}AlX (X = Cl, 5; OiPr, 6) and {(Ar)ON(Cy)NO(CF3)}-Y(N(SiHMe(2))(2))(THF) (7) in high yields, with concomitant alkane, alcohol, and amine elimination, respectively. Single-crystal X-ray diffraction studies revealed that complexes 5 and 7 are mononuclear in the solid state with, respectively, five-coordinated distorted square-pyramidal and six-coordinated distorted octahedral geometries. Complexes 5-7 were also characterized in C(6)D(6) solution by (1)H, (13)C, and (19)F NMR spectroscopy, which indicated the existence of only one isomer at room temperature. Al-OiPr complex 5 is an effective, though sluggish, initiator for the ring-opening polymerization of racemic lactide, giving polymers with a highly isotactic-enriched microstructure (P(meso) = 0.87), molecular weights that match well the calculated values, and narrow polydispersities (M(w)/M(n) = 1.04-1.18).

• 出版日期2009-3-9