ORGANOAMIDO-LANTHANOIDS AND ARYLOXO-LANTHANOIDS .2. PREPARATION OF TRIS(2,6-DIPHENYLPHENOXO)-LANTHANOID(III) COMPLEXES AND THE X-RAY STRUCTURES OF LOW-COORDINATE [YB(O-2,6-PH2C6H3)3] CONTAINING AN INTRAMOLECULAR CHELATE YB ... PI-ARENE INTERACTION, AND [YB(O-2,6-PH2C6H3)3(THF)2].THF (THF = TETRAHYDROFURAN)

Bulky monomeric lanthanoid(III) aryl oxides Ln(Odpp)3 (Odpp = 2, 6-diphenylphenoxide; Ln = Nd, Sm, Er, Yb or Lu) have been prepared by reaction between the lanthanoid metal, Hg(C6F5)2, and HOdpp in tetrahydrofuran (thf), and Yb(Odpp)3 has also been obtained from an analogous reaction of (PhCC)2Hg. Cleavage of Ln(η5-C5H5)3 (Ln = Nd or Yb) with HOdpp also yields Ln(Opdd)3. The aryl oxides have been isolated as [Ln(Odpp)3(thf)2] (Ln = Nd, Sm or Yb) or as the homoleptic complexes Ln(Odpp)3 (Ln = Nd, Er, Yb or Lu). The X-ray crystal structure of [Yb(Odpp)3(thf)2].thf [crystals monoclinic, space group P21/n, a 11.009(4), b 32.134 (7), c 15.498(6) Å, β 96.72(3)°, Z 4; 2785 data refined to R 0.039] shows the complex to have distorted square pyramidal stereochemistry with apical and transoid basal Odpp ligands, < Yb-Odpp > 2.078(9) Å, and transoid basal thf ligands, (Yb-O(thf)> 2.305(8) Å. Similarly, Yb(Odpp)3 [crystals triclinic, space group P1, a 15.934(2), b 13.563(1), c 10.968(2)Å, α 116.71(1), β 92.90(2), v 103.38(1)°, Z 2; 6236 data refined to R 0.031] was shown to have a trigonal pyramidal arrangement of oxygen donor atoms [< Yb-O > 2.065(4) Å; < O-Yb-O > 117.5(1)°], a novel intramolecular chelate Yb…π-arene interaction, < Yb…C > 2.978(6)Å, and an agostic Yb … CH interaction. © 1990 ASEG.