Lanthanide-alkali metal sandwich complexes: synthesis, structure, and solvent-mediated redox transformations, and
Cheng-Ling Pan1, Xingwei Li, Hongjie Zhang
1State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, China.
Abstract:
Reaction of the potassium salt of amido ligand [Ph(2)Si(NAr)(2)](2-) (L, Ar = 2,6-iPr(2)C(6)H(3)) and LnI(2)(thf)(2) (Ln = Sm, Yb) gives sandwich complexes [(L)(2)Ln{K(Et(2)O)}(2)] (Ln = Sm (2), Yb (3)) with potassium-arene pi interactions. Reaction of 2 with azobenzene gave the dimeric samarium cluster [(L)(2)Sm(2)(mu-eta(2):eta(2)-N(2)Ph(2))(2){K(thf)(2)}(2)] (4) and the tetrameric [(L)Sm(4) (mu-eta(2):eta(2)-N(2)Ph(2))(3) (mu(3)-NPh)(2)(thf)(3)] (5). On the other hand, the reaction of 2 with alpha-diimines ligands ArN=CRCR=NAr (DAD, R = H, Me) gives two Sm(III) complexes: polymeric [(L)Sm{(ArN)RC=CR(NAr)}K](n) (R = H (6), Me (7)) assembled through cation-pi interactions and byproduct [{(L)(2)Sm}{K(thf)(6)}] (8). Complexes 2-8 have been fully characterized by elemental analyses and X-ray crystallography. In particular, crystallographic analyses of 6 and 7 revealed that in both complexes samarium(III) is stabilized by dianionic DAD units.
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