Pinwheel-Shaped Heterobimetallic Lanthanide Alkali Metal Binaphtholates: Ionic Size Matters!

Anhydrous alkali metal lanthanide binaphtholates M3[Ln(binol)3] (M = Li, Na; Ln =
lanthanide or yttrium; H2binol = binaphthol) are prepared by reaction of [Ln{N(SiMe3)2}3]
with 3 equiv of MHbinol. Reaction of [Ln{N(SiMe3)2}3] (Ln = Y or Yb) with 3 equiv of rac-LiHbinol gives a racemic mixture of RRS- and SSR-Li3[Ln(binol)3] 2 as the only product. In
contrast, reaction of [Ln{N(SiMe3)2}3] with 3 equiv of rac-NaHbinol gives a racemic mixture
of RRR- and SSS-Na3[Ln(binol)3] when Ln = Y. When Ln = Yb, a 3:1 mixture of RRR-/SSS- and RRS-/SSR-Na3[Ln(binol)3] is formed. Complexes have been characterized in
solution by NMR spectroscopy. The 3-proton of the unique binol ligand in RRS- and SSR-Li3[Y(binol)3] is shifted upfield by interaction with the π-system of a neighboring naphthyl
ring. Analysis of paramagnetically induced 1H NMR shifts of Yb complexes shows them to
be entirely dipolar in origin. X-ray crystal structures have been determined for the following
compounds:  rac-[Li(THF)2]3[Y(binol)3]·THF, 2a; rac-[Na(THF)2]3[Y(binol)3], 3; [Li(OEt2)]3[Eu(S-binol)3]·[Li(OEt2)]3[Eu(S-binol)3(H2O)]·2Et2O, 4; [Li(THF)2]2[Li(OEt2)][Yb(S-binol)3]·THF, 5; [Na(THF)2]3[Yb(S-binol)3], 6; [Na(THF)2]3[La(S-binol)3(H2O)], 7.

无水碱金属镧系元素双萘酚酸盐M3[Ln(binol)3]（M = Li, Na；Ln = 镧系元素或钇；H2binol = 双萘酚）通过[Ln{N(SiMe3)2}3]与3等当量的MHbinol反应制备。当[Ln{N(SiMe3)2}3]（Ln = Y或Yb）与3等当量的rac-LiHbinol反应时，产生RRS-和SSR-Li3[Ln(binol)3]2的消旋混合物，作为唯一产物。相比之下，当[Ln{N(SiMe3)2}3]与3等当量的rac-NaHbinol反应时，若Ln = Y，则产生RRR-和SSS-Na3[Ln(binol)3]的消旋混合物。当Ln = Yb时，形成RRR-/SSS-与RRS-/SSR-Na3[Ln(binol)3]的3:1混合物。这些配合物通过核磁共振波谱在溶液中进行了表征。在RRS-和SSR-Li3[Y(binol)3]中，独特的binol配体的3个质子因与相邻萘环的π系统相互作用而向场位移。对钇配合物的顺磁诱导1H NMR位移的分析表明，其完全源于偶极起源。以下化合物的X射线晶体结构已经确定：rac-[Li(THF)2]3[Y(binol)3]·THF，2a；rac-[Na(THF)2]3[Y(binol)3]，3；[Li(OEt2)]3[Eu(S-binol)3]·[Li(OEt2)]3[Eu(S-binol)3(H2O)]·2Et2O，4；[Li(THF)2]2[Li(OEt2)][Yb(S-binol)3]·THF，5；[Na(THF)2]3[Yb(S-binol)3]，6；[Na(THF)2]3[La(S-binol)3(H2O)]，7。