| Popis: |
Five- and six-coordinate scandium and yttrium complexes of the recently described diamide–diamine donor ligand N2NN′ (where H2N2NN′ = (2-C5H4N)CH2N{CH2CH2N(H)SiMe3}2) are described. Reaction of ScCl3 with Li2N2NN′ gave five-coordinate [ScCl(N2NN′)] 1 in excellent yield. The corresponding reaction with YCl3 in tetrahydrofuran (thf) or pyridine (py) solution afforded “ate” complexes best described as [YCl(N2NN′)(L)]·1.5(LiCl) (L = thf 2 or py 3). The two chloride complexes 1 and 2 are useful starting materials for primary and secondary amide, benzamidinate and alkyl complexes of Sc and Y supported by the N2NN′ ligand. Thus reaction of 1 or 2 with LiN(SiMe3)2·Et2O, LiNMe2 or LiNHR (R = tBu or Ar, where Ar = 2,6-C6H3iPr2) gave the corresponding five-coordinate amide derivatives [M(NRR″)(N2NN′)] (M = Sc, R = R″ = SiMe34 or Me 6, or R = H, R″ = tBu 8 or Ar 9; M = Y, R = R″ = SiMe35, or R = H, R″ = Ar 10). The crystal structure of 5 is described. The σ-bond metathesis reaction of [Sc(NMe2)(N2NN′)] 6 with ArFNH2 (ArF = C6F5) gave the corresponding primary flurophenylamide derivative 7. The reaction of 1 or 2 with Li[PhC(NSiMe3)2] gave the fluxional, six-coordinate benzamidinate derivatives [M{PhC(NSiMe3)2}(N2NN′)] (M = Sc 11 or Y 12), the crystal structures of which are reported. Finally, reaction of 1 with LiCH2SiMe3 formed the alkyl derivative [Sc(CH2SiMe3)(N2NN′)] 13 in reasonable yield; the crystal structure of 13 is described. |
