Organoamido‐ and Aryloxo‐Lanthanoids, 17 Novel Low‐Coordinate Lanthanoid (II) and ‐(III) Aryloxide Complexes ‐ the X‐ray Structures of Bis (2,6‐diphenylphenolato) tris(tetrahydrofuran)‐ytterbium (II), Bis(1,2‐dimethoxyethane)bis(2,6‐diphenylphenolato)ytterbium(II),‐neodymium(III)

Abstract

Novel Low-Coordinate Lanthanoid(I1) and -(III) Aryloxide Complexes -the X-ray Structures of Bis(2,6-diphenylphenolato)tris(tetrahydrofuran)-ytterbium(II), Bis( 1,2-dime t hox yet hane) bis( 2,6-dip henylphenola t 0) ytterbium( 11), and 1,2-Dimet hox ye t hane tris( 2,6-diphenylphenolato)yt ter bium(II1) and -neodymium ( 111 IntroductionIn the family of lanthanoid(II1) complexes with bulky aryloxide ligands12-6', which include 2,6-di-tevt-butyl-4-Xphenolates (e.g. X = H, tBu, 2,6-diisopropylphenoIates181 and 2,6-dimethylphen0lates[~], lanthanoid tris(2,6-diphenylphenolates) Ln(Odpp)3 occupy a distinctive position. (2) We now report the synthesis of ytterbium(I1) 2,6-diphenylphenolate by reduction of Yb(Odpp),, and the X-ray crystal structures of [Yb(Odpp)2(THF),1 and [Yb(od~p)~(DME)~l, (DME = 1,2-dimethoxyethane). In addition, the structurcs of the novel five-coordinate lanthanoid(II1) complexes [L1i(0dpp)~(DME)] (Ln = Nd or Yb) have also been determined. Results and Discussion SynthesisReduction of tris(2.6-diphenylphenolato)ytterbium(III) to the ytterbium(I1) complex was achieved by prolonged

Carbon-Bridged Bis(phenolato)lanthanide Alkoxides: Syntheses, Structures, and Their Application in the Controlled Polymerization of ε-Caprolactone

“…The Nd−C(Cp) bond lengths range from 2.738(5) to 2.822(5) Å, giving an average of 2.784(6) Å, which is comparable well with that in (C 5 H 5 )NdCl 2 (THF) 3 . The Nd−O(Ar) bond lengths of 2.165(3) and 2.181(3) Å are comparable with those in [(ArO) 3 Nd(THF)] (ArO = 2,6-di- tert -butyl-4-methylphenolate) (2.176 Å), [Nd(Odpp) 3 (DME)] (2.191 Å) (Odpp = 2,6-diphenylphenolate), [Nd(Odpp) 3 (THF) 2 ] (2.190 Å), [Nd(Odpp) 3 (THF)] (2.193 Å), and Nd(Odpp) 3 (2.169 Å) 11 but slightly shorter than those in [Na(THF) 6 ][Nd(ArO) 4 ] (2.230 Å) 9 and K[Nd(OC 6 H 3 Pr i 2 -2,6) (2.211 Å) . The C−O distances of the phenolate ligands of 1.330(5) and 1.332(5) Å, respectively, are apparently shorter than the single bond length, reflecting substantial electron delocalization from the oxygen into the aromatic rings.…”

Homoleptic Rare-Earth Metal Complexes Containing Ln−C σ-Bonds

“…Redox-transmetalation followed by ligand exchange with 2,6-diphenylphenol exclusively yields phenolate complexes with trivalent rare-earth metals, even for the lanthanides with accessible divalent oxidation states. Depending on the workup and the crystallization procedures, homoleptic tris(phenolate) complexes Ln(OC 6 H 3 Ph 2 -2,6) 3 (thf) x with varying amounts of coordinating donor molecules have been isolated (Chart , 242 ). ,, The corresponding divalent ytterbium phenolate Yb(OC 6 H 3 Ph 2 -2,6) 2 (thf) 3 could only be obtained by reduction of the Yb(III) species with ytterbium powder and mercury metal . Further substitution in the 3- and 5-position of the phenolate ligand produced sterically hindered complexes 243 with low metal coordination numbers .…”

Advances in Structurally Characterized Lanthanide Alkoxide, Aryloxide, and Silyloxide Compounds

“…Other oxidation states have also been accessed for certain members of the series. In molecular complexes, the divalent oxidation state (Ln +2 ) has been observed. – In the case of cerium, several tetravalent complexes (Ce +4 ) have also been characterized. , The main +3 and +2 synthesis routes are discussed below.…”

“…A divalent Yb 2+ DPP adduct was also isolated exhibiting numerous π-interactions . The π-interaction are easily disrupted upon the introduction of suitable donor solvents noted in the cases of Ln(DPP) 3 (solv) x where Ln(solv) x = La(THF) 2 , , Ce(THF) 2 , Nd(THF), , Nd(THF) 2 , , Nd(DME), Yb(DME), and system Yb(THF) 2 . , Solvated adducts of some lanthanide DPP analogs (or their 3,5-substituted derivatives, DPP-R 2 -3,5) are also described, including Ln(DPP-R 2 -3,5) 3 (solv) x where R = H: La(THF) 2 (Figure b), , Yb(THF); R= Bu t : Sc(THF) (Figure c) and Yb(THF); R = Ph: Yb(DME) . In addition an unusual charge separated species was observed in the case of [Yb 2 (μ-η 6 -DPP) 3 ][Yb(DPP) 4 ] (Figure d) and divalent complexes were isolated as Ln(DPP) 2 (solv) x where Ln(solv) x = Yb(DME) 2 , Yb(THF) 3 …”