Dinuclear Dysprosium and Ytterbium Complexes Incorporating N,N‐Bis(pyrrolyl‐α‐methyl)‐N‐methylamine Ligand: Syntheses and Structures

Reaction of DyCl₃ with two equivalents of NaN(SiMe₃)₂ in THF yielded {Dy(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂ ( 1 ). X‐ray crystal structure analysis revealed that 1 is a centrosymmetric dimer with asymmetrically bridging chloride ligands. The metal coordination arrangement can be best described as distorted trigonal bipyramid. The bond lengths of Ln–Cl and Ln–N showed a decreasing trend with the contraction of the size of Ln³⁺. Treatment of N,N‐bis(pyrrolyl‐α‐methyl)‐N‐methylamine (H₂dpma) with 1 and known compound {Yb(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂, respectively, led to the formations of [Dy(μ‐Cl)(dpma)(THF)₂]₂ ( 2 ) and {Yb(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂ ( 3 ). Compounds 2 and 3 were fully characterized by single‐crystal X‐ray crystallography, elemental analysis, and ¹H NMR spectroscopy. Structure determination indicated that 2 and 3 exhibit as centrosymmetric dimers with asymmetrically bridging chloride ligands. One pot reactions involving LnCl₃ (Ln = Dy and Yb), LiN(SiMe₃)₂, and H₂dpma were explored and desired products 2 and 3 were not yielded, which indicated that 1 and {Yb(μ‐Cl)[N(SiMe₃)₂]₂(THF)}₂ are the demanding precursors to synthesize Dysprosium and Ytterbium complexes supported by dpma^2– ligand. Compounds 2 and 3 are the first reported lanthanide complexes chelated by dpma^2– ligand.     

Polymerization of n‐phenyl maleimide by lanthanide complexes

N‐Phenyl maleimide (N‐PMI) was successfully polymerized by divalent rare‐earth complexes (ArO)₂Sm(THF)₄ (ArO = 2,6‐di‐tert‐butyl‐4‐methyl phenoxo‐; THF = tetrahydrofuran) and (Ar′O)₂Ln(THF)₃ (Ar′O = 2,6‐di‐tert‐butyl phenoxo‐; Ln = Sm, Yb, or Eu). The central metals greatly affected the reactivity, and the reactivity order was Sm(II) > Yb(II) > Eu(II). The activity of (Ar′O)₂Sm(THF)₃ was higher than that of (ArO)₂Sm(THF)₄. The polymerization yields were higher in THF than in other solvents, and the maximum yields were obtained around 25 °C. A proposed mechanism is discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3966–3972, 2005     

Crystallographic report: Crystal structure of bis(2,4,6‐tri‐tert‐butylphenolato‐O) bis(tetrahydrofuran‐O) samarium (N,N‐η2‐azobenzene) diethyl ether solvate

Reaction of divalent Sm(OAr)₂(THF)₃ (Ar = C₆H₂‐tert‐Bu₃‐2,4,6; THF = tetrahydrofuran) with one equivalent of azobenzene in THF and crystallization of the product in diethyl ether afforded the title complex (ArO)₂(THF)₂Sm(η²‐N₂Ph₂)·Et₂O in good yield. In the complex, the N? N bond length for the azobenzene species is lengthened. The two Sm? N bonds are equivalent, and their bond lengths are intermediate between the donor bond and the single bond. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis,Structural Characterization,and Catalytic Activity of Scandium,Samarium, and Dysprosium Complexes Supported by Tris(pyrrolyl‐α‐methyl)amine Ligand

The synthesis, structures and catalytic activities of three organolanthanide complexes supported by the H₃tpa ligand (H₃tpa = tris(pyrrolyl‐α‐methyl) amine) are described. Treatment of H₃tpa with one equivalent of Ln[N(SiMe₃)₂]₃ (Ln = Sc, Sm, Dy) in THF gives, after recrystallization from toluene/THF solution, Sc(tpa)(THF)₂ ( 1 ), Sm(tpa)(THF)₃ ( 2 ) and Dy(tpa)(THF)₃ ( 3 ) in good yields. The structures of complexes 1 – 3 were determined by single‐crystal X‐ray diffraction and elemental analysis. Complexes 2 and 3 exhibited good catalytic activity for the polymerization of ?‐caprolactone.     

Syntheses,Structures, and Photoluminescence of Lanthanide Coordination Polymers Based on 4‐Oxo‐1,4‐dihydro‐2,6‐pyridinedicarboxylic acid

Investigating the coordination chemistry of H₂CDA (4‐oxo‐1,4‐dihydro‐2,6‐pyridinedicarboxylic acid) with rare earth salts Ln(NO₃)₃ under hydrothermal conditions, structure transformation phenomenon was observed. The ligand, H₂CDA charged to its position isomer, enol type structure, H₃CAM (4‐hydroxypyridine‐2,6‐dicarboxylic acid). Six new lanthanide(III) coordination polymers with the formulas [Ln(CAM)(H₂O)₃]_n [Ln = La ( 1 ), Pr, ( 2 )] and {[Ln(CAM)(H₂O)₃] · H₂O}_n [Ln = Nd, ( 3 ), Sm, ( 4 ), Eu, ( 5 ), Y, ( 6 )] were synthesized and characterized. The X‐ray structure analyses show two kinds of coordination structures. The complexes 1 and 2 and 3 – 6 are isostructural. Complexes 1 and 2 crystallize in the monoclinic C₂/c space group, whereas 3 – 6 crystallize in the monoclinic system with space group P2₁/n. In the two kinds of structures, H₃CAM displays two different coordination modes. The Sm^III and Eu^III complexes exhibit the corresponding characteristic luminescence in the visible region at an excitation of 376 nm.     

2,2′‐Bipyrimidine as Efficient Sensitizer of the Solid‐State Luminescence of Lanthanide and Uranyl Ions from Visible to Near‐Infrared

Treatment of Ln(NO₃)₃?nH₂O with 1 or 2 equiv 2,2′‐bipyrimidine (BPM) in dry THF readily afforded the monometallic complexes [Ln(NO₃)₃(bpm)₂] (Ln=Eu, Gd, Dy, Tm) or [Ln(NO₃)₃(bpm)₂]?THF (Ln=Eu, Tb, Er, Yb) after recrystallization from MeOH or THF, respectively. Reactions with nitrate salts of the larger lanthanide ions (Ln=Ce, Nd, Sm) yielded one of two distinct monometallic complexes, depending on the recrystallization solvent: [Ln(NO₃)₃(bpm)₂]?THF (Ln=Nd, Sm) from THF, or [Ln(NO₃)₃(bpm)(MeOH)₂]?MeOH (Ln=Ce, Nd, Sm) from MeOH. Treatment of UO₂(NO₃)₂?6H₂O with 1 equiv BPM in THF afforded the monoadduct [UO₂(NO₃)₂(bpm)] after recrystallization from MeOH. The complexes were characterized by their crystal structure. Solid‐state luminescence measurements on these monometallic complexes showed that BPM is an efficient sensitizer of the luminescence of both the lanthanide and the uranyl ions emitting visible light, as well as of the Yb^III ion emitting in the near‐IR. For Tb, Dy, Eu, and Yb complexes, energy transfer was quite efficient, resulting in quantum yields of 80.0, 5.1, 70.0, and 0.8 %, respectively. All these complexes in the solid state were stable in air.     

4,5‐Dichlorophthalate‐Extended Lanthanide Coordination Polymers with Layer and Ribbon Motifs: Synthesis,Structure, and Luminescence

Five new 4,5‐dichlorophthalate (dcpa)‐extended lanthanide coordination polymers (CPs) with formulas [Ln₂(H₂O)(dcpa)₃]_n (Ln = Tb for 1 , Sm for 2 , Pr for 3 , and Nd for 4 ) and [Yb(H₂O)₂(dcpa)(Hdcpa)]_n ( 5 ) were solvothermally synthesized. Structural determinations demonstrate that CPs 1 – 4 are crystallographically isostructural, exhibiting an infinite two‐dimensional layer with dimeric {Ln₂(COO)₃} subunits extended by aromatic skeleton of fully deprotonated dcpa^2– connectors. In contrast, complex 5 features a one‐dimensional broad ribbon with centrosymmetric {Yb₂(COO)₂} subunits propagated by pairs of ditopic dcpa^2– ligands. Interestingly, the anionic dcpa^2– connector can serve as a good antenna ligand to sensitize the characteristic emissions of the different Ln^III ions in both the ultraviolet (for 1 – 3 ) and near‐infrared (for 4 and 5 ) regions.     

Synthesis of ferrocene‐containing N‐aryloxo β‐ketoiminate lanthanide complexes and polymerization of ε‐caprolactone

The synthesis, characterization and ε‐caprolactone polymerization behavior of lanthanide amido complexes stabilized by ferrocene‐containing N‐aryloxo functionalized β‐ketoiminate ligand FcCOCH₂C(Me)N(2‐HO‐5‐Bu^t‐C₆H₃) (LH₂, Fc = ferrocenyl) are described. The lanthanide amido complexes [LLnN(SiMe₃)₂(THF)]₂ [Ln = Nd ( 1 ), Sm ( 2 ), Yb ( 3 ), Y ( 4 )] were synthesized in good yields by the amine elimination reactions of LH₂ with Ln[N(SiMe₃)₂]₃(µ‐Cl)Li(THF)₃ in a 1:1 molar ratio in THF. These complexes were characterized by IR spectroscopy and elemental analysis, and ¹H NMR spectroscopy was added for the analysis of complex 4 . The definitive molecular structures of complexes 1 and 3 were determined by X‐ray diffraction studies. Complexes 1 – 4 can initiate the ring‐opening polymerization of ε‐caprolactone with moderate activity. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis,Characterization and Photoluminescence of Lanthanide Metal‐organic Frameworks,Constructed from Triangular 4,4′,4″‐s‐triazine‐1,3,5‐triyl‐p‐aminobenzoate Ligands

Eight isomorphous metal‐organic frameworks: [Ln₂(TATAB)₂(H₂O)(DMA)₆]·5H₂O (Ln = Sm ( 1 ), Eu ( 2 ), Gd ( 3 ), Tb ( 4 ), Dy ( 5 ), Er ( 6 ), Tm ( 7 ), Yb ( 8 )); TATAB = 4,4′,4″‐s‐triazine‐1,3,5‐triyl‐p‐aminobenzoate, DMA = N,N‐dimethylacetamide), were synthesized by the self‐assembly of lanthanide ions, TATAB, DMA and H₂O. Single‐crystal X‐ray crystallography reveals they are three dimensional frameworks with 2‐fold interpenetration. Solid‐state photoluminescence studies indicate ligand‐to‐metal energy transfer is more efficient for compounds 2 and 4 which exhibit intense characteristic lanthanide emissions at room temperature.     

Organometallic Compounds of the Lanthanides. 157 [1] The Molecular Structure of Tris(trimethylsilylmethyl)samarium, ‐erbium, ‐ytterbium,and ‐lutetium

SmCl₃ reacts with Me₃SiCH₂Li in THF yielding Sm(CH₂SiMe₃)₃(THF)₃ ( 1 ). The single crystal X‐ray structural analyses of 1 , Er(CH₂SiMe₃)₃(THF)₂ ( 2 ), Yb(CH₂SiMe₃)₃(THF)₂ ( 3 ), and Lu(CH₂SiMe₃)₃(THF)₂ ( 4 ) show the Sm atom in a fac‐octahedral coordination and the heavier lanthanides Er, Yb, and Lu trigonal bipyramidally coordinated with the three alkyl ligands in equatorial and two THF molecules in axial positions.     

Two‐Dimensional and Three‐Dimensional Lanthanide Coordination Polymers Built from 4‐Hydroxypyridine‐2,6‐dicarboxylic Acid Ligand

4‐Hydroxypyridine‐2,6‐dicarboxylic acid (H₃CAM) reacts with Ln₂O₃(Ln = La, Ce) or Ln(NO₃)₃ (Ln = Sm, Dy, Gd, Ho) in hydrothermal reactions to form a series of lanthanide coordination polymers 1 – 6 . Elemental analysis, IR spectra and X‐ray crystal structure analysis were carried out to determine the composition and crystal structure of 1 – 6 . Compounds 1 and 2 are isostructural and contain tetranuclear metallic ring unit and 3D framework. 4 – 6 are isostructural contain 2D network. Furthermore, the photoluminescent properties of 3 and 4 at room temperature were also studied.     

Synthesis and Structure of 1—Cyclopentylindenyl Lanthanide（Ⅱ）Complexes and Their Catalytic Behavior for Polymerization of Acrylonitrile

The reaction between K(1‐C₅H₉C₉H₆) and anhydrous LnCl₃ (Ln=Sm, Yb) in the molar ratio of 2:1 in THF with subsequent treatment by Na‐K alloy afforded (1‐C₅H₉C₉H₆)₂Ln‐(THF)_n(Ln=Sm, n=1; Ln=Yb, n=2), while the reaction of Sml₂ with K(1‐C₅H₉C₉H₆) in the molar ratio of 1:2 in THF gave the anionic complex K(1‐C₅H₉C₉H₆)₃Sm(THF)₃. The X‐ray structure of (1‐C₅H₉C₉H₆)₂Yb(THF)₂ showed that central metal Yb is coordinated by two cyclopentadienyl rings of 1‐cyclopentylindenyls and two oxygen atoms from two tetrahydrofuran molecules to form pseudo‐tetrahedral coordinate geometry. All these complexes are active for the polymerization of acrylonitrile.     

β‐Diketiminatoytterbium aryloxides: synthesis,structural characterization,and catalytic activity for addition of amines to carbodiimides

The steric effect of an aryloxido group on the synthesis and molecular structures of ytterbium aryloxides supported by β‐diketiminato ligand L (L = [N(2,6‐Me₂C₆H₃)C(Me)]₂CH^?) is reported. Reactions of β‐diketiminatoytterbium dichloride, LYbCl₂(THF)₂, with NaOAr¹ in THF (Ar¹ = [2,6‐^tBu₂‐4‐MeC₆H₂], THF = tetrahydrofuran) at 60°C gave the corresponding ytterbium complexes LYb(OAr¹)Cl(THF) ( 1 ) and LYb(OAr¹)₂ (1), depending on the molar ratio of dichloride to sodium aryloxide, respectively, while the same reactions with NaOAr² and NaOAr³ (Ar² = [2,6‐ⁱPr₂C₆H₃], Ar³ = [2,6‐Me₂C₆H₃]) in 1:1 or 1:2 molar ratio in THF afforded only bisaryloxide complexes LYb(OAr²)₂(THF) (1) and LYb(OAr³)₂(THF) ( 4 ) in good yields, respectively. Complexes 1 , 2 , 3 , 4 were fully characterized, including X‐ray crystal structure analyses. All the complexes are efficient pre‐catalysts for the catalytic addition of amines to carbodiimides giving guanidines. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis,Crystal Structure,and Catalytic Properties of Porous 3d‐4f Heterometallic Coordination Polymers Constructed from Pyrazine‐2,3‐dicarboxylic Acid

Reactions of pyrazine‐2,3‐dicarboxylic acid (H₂pzdc), cobalt nitrate and lanthanide (Ln) oxide under hydrothermal conditions result in four new 3d‐4f heterometal coordination polymers, namely, [Ln₂Co(pzdc)₄(H₂O)₆] · 2H₂O [Ln = La ( 1 ), Pr ( 2 ), Eu ( 3 ) and Gd ( 4 )]. All compounds were characterized by elemental analysis, infrared spectroscopy, thermal gravimetric analysis, and X‐ray diffraction. The compounds exhibit a three‐dimensional (3D) brick‐like structure with rectangular‐shaped nano‐scale channels along a axis direction, made up of wave‐like layers containing [Ln(pzdc)]⁺ units, which are connected by one‐dimensional (1D) chain of [Co(pzdc)₂]^2–. The catalytic properties of compounds 1 and 3 were investigated in the synthesis of cyanohydrins at room temperature under solventless conditions. They showed similar catalytic activities with very high conversions of benzaldehyde and high selectivity towards cyanohydrin. The control experiment without addition of the coordination polymers only reached 16 % conversion. Other aldehydes could also be converted totally under shorter reaction times also with very high selectivities for the corresponding cyanohydrins. Compound 1 could also be recycled in another catalytic cycle.     

Aluminum Complexes Stabilized by Piperazidine‐Bridged Bis(phenolate) Ligands: Syntheses,Structures, and Application in the Ring‐Opening Polymerization of ε‐Caprolactone

The synthesis and characterization of aluminum alkoxide and alkyl complexes stabilized by piperazidine‐bridged bis(phenolate) ligands are described. Treatment of ligand precursors H₂[ONNO]¹ {H₂[ONNO]¹=1,4‐bis(2‐hydroxy‐3‐tert‐butyl‐5‐methylbenzyl)piperazidine} and H₂[ONNO]² {H₂[ONNO]²=1,4‐bis(2‐hydroxy‐3,5‐di‐tert‐butylbenzyl)piperazidine} with AlEt₂(OCH₂Ph) and AlEt₂(OPr‐i), which were generated in situ by the reactions of AlEt₃ with equivalent of the corresponding alcohols, in a 1:1 molar ratio in THF gave the corresponding aluminum alkoxide complexes [ONNO]¹Al(OCH₂Ph) ( 1 ) and [ONNO]²Al(OPr‐i) ( 2 ), respectively. The reaction of H₂[ONNO]¹ with AlEt₂(OCH₂Ph) in a 1:2 molar ratio in THF afforded a mixture of monometallic aluminum ethyl complex [ONNO]¹AlEt ( 3 ) and complex 1 , which can be isolated by stepwise crystallization. Similarly, H₂[ONNO]² reacted with AlEt₂(OPr‐i) in a 1:2 molar ratio in THF to give a mixture of aluminum ethyl complex [ONNO]²AlEt ( 4 ) and complex 2 . Complexes 1 and 2 were also available via treatment of complexes 3 and 4 with 1 equiv. of benzyl alcohol and isopropyl alcohol, respectively. All of these complexes were fully characterized including X‐ray structural determination. It was found that complexes 1 to 4 can initiate the ring‐opening polymerization of ε‐caprolactone, and complexes 1 and 2 showed higher catalytic activity in comparison with complexes 3 and 4 .     

The Syntheses,Structures, and Magnetic Properties of Four 2D Lanthanide(III)‐naphthalenedicarboxylic Complexes

Four Ln‐NDC coordination polymers [Ln(NDC)(HNDC)(H₂O)] (Ln = La ( 1 ), Pr ( 2 ), Nd ( 3 ), Sm ( 4 ), H₂NDC = 1,4‐naphthalenedicarboxylic acid) were hydrothermally synthesized and structurally characterized by elemental analyses, IR spectroscopy, and single‐crystal X‐ray diffraction. Compounds 1 – 4 are isomorphous, and their structures display a layer constructed from a Ln‐organic chain and NDC^2– ligand, in which the H₂NDC ligands adopt two different acidity‐dependent types and coordination modes: HNDC^1– with μ‐η¹:η¹ and NDC^2– with μ‐η¹:η²:η¹:η². The 3D supramolecular networks of 1 – 4 are mainly controlled by hydrogen bonds interactions. The magnetic susceptibilities of complexes 2 – 4 reveal overall antiferromagnetic interactions between the Ln^III ions. In addition, thermogravimetric analysis of compound 2 is described.     

Systematic Investigation of Reaction‐Time Dependence of Three Series of Copper–Lanthanide/Lanthanide Coordination Polymers: Syntheses,Structures, Photoluminescence,and Magnetism

Three series of copper–lanthanide/lanthanide coordination polymers (CPs) Ln^IIICu^IICu^I(bct)₃(H₂O)₂ [Ln=La ( 1 ), Ce ( 2 ), Pr ( 3 ), Nd ( 4 ), Sm ( 5 ), Eu ( 6 ), Gd ( 7 ), Tb ( 8 ), Dy ( 9 ), Er ( 10 ), Yb ( 11 ), and Lu ( 12 ), H₂bct=2,5‐bis(carboxymethylmercapto)‐1,3,4‐thiadiazole acid], Ln^IIICu^I(bct)₂ [Ln=Ce ( 2 a ), Pr ( 3 a ), Nd ( 4 a ), Sm ( 5 a ), Eu ( 6 a ), Gd ( 7 a ), Tb ( 8 a ), Dy ( 9 a ), Er ( 10 a ), Yb ( 11 a ), and Lu ( 12 a )], and Ln^III₂(bct)₃(H₂O)₅ [Ln=La ( 1 b ), Ce ( 2 b ), Pr ( 3 b ), Nd ( 4 b ), Sm ( 5 b ), Eu ( 6 b ), Gd ( 7 b ), Tb ( 8 b ), and Dy ( 9 b )] have been successfully constructed under hydrothermal conditions by modulating the reaction time. Structural characterization has revealed that CPs 1 – 12 possess a unique one‐dimensional (1D) strip‐shaped structure containing two types of double‐helical chains and a double‐helical channel. CPs 2 a – 12 a show a three‐dimensional (3D) framework formed by Cu^I linking two types of homochiral layers with double‐helical channels. CPs 1 b – 9 b exhibit a 3D framework with single‐helical channels. CPs 6 b and 8 b display visible red and green luminescence of the Eu^III and Tb^III ions, respectively, sensitized by the bct ligand, and microsecond‐level lifetimes. CP 8 b shows a rare magnetic transition between short‐range ferromagnetic ordering at 110 K and long‐range ferromagnetic ordering below 10 K. CPs 9 a and 9 b display field‐induced single‐chain magnet (SCM) and/or single‐molecule magnet (SMM) behaviors, with U_eff values of 51.7 and 36.5 K, respectively.     

Syntheses,Structures, and Magnetism of Trinuclear Zn2Ln Complexes with 2,6‐Dipicolinoylbis(N,N‐diethylthiourea)

The bifunctional ligand 2,6‐dipicolinoylbis(N,N‐diethylthiourea) (H₂L) readily reacts with mixtures of Zn(CH₃COO)₂ and LnCl₃ in MeOH at ambient temperature with formation of trinuclear heterobimetallic complexes [Zn₂Ln(L)₂(OAc)₃] ( 1a – 1f ) (Ln = Ce, Nd, Sm, Gd, Dy, Er). The X‐ray single‐crystal diffraction and structural studies of the complexes revealed their isostructural nature, in which two doubly‐charged ligands {L^2–} bind two Zn²⁺ ions with the terminal acylthiourea sites and one Ln³⁺ ion with the central 2,6‐pyridinedicarboxamide site. In the complexes, the coordination numbers of Ln^III and Zn^II ions are 9 and 5, respectively. Magnetic properties of the complexes were studied by temperature‐dependent dc magnetic measurements. The observed μ_eff values at room temperature are all closed to the calculated values. Fitting χ_M and M data of [Zn₂Gd(L)₂(OAc)₃] ( 1d ) shows a g_iso value of 1.94.     

Anionic lanthanide phenoxide complexes as novel single‐component initiators for the polymerization of ε‐caprolactone and trimethylene carbonate

The anionic lanthanide‐sodium‐2,6‐di‐tert‐butyl‐phenoxide complexes [Ln(OAr)₄][Na(DME)₃]·DME (Ln = Nd 1 (neodymium), Sm 2 (samarium), or Gd 3 (gadolium); DME = dimethoxyethane) were synthesized by the reaction of anhydrous LnCl₃ with 4 equiv of sodium‐2,6‐di‐tert‐butyl‐phenoxide NaOAr in high yields and structurally characterized. These complexes showed high catalytic activity in the ring‐opening polymerizations of ?‐caprolactone (?‐CL) and trimethylene carbonate (TMC). The catalytic activity profoundly depended on the lanthanide metals. The active order of Gd < Sm < Nd for the polymerization of ?‐CL and TMC was observed. The polymers obtained with these initiators all showed a unimodal molecular weight distribution, indicating that the [Ln(OAr)₄][Na(DME)₃]·DME anionic complexes could be used as single‐component initiators. The anionic complex was more efficient than the corresponding neutral complex, Ln(OAr)₃(THF)₂. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1210–1218, 2007     

配合物(ArO)2Yb(NPh2)2K(THF)4(Ar=C6H2-t-Bu3-2,4,6)的合成、分子结构和催化行为

Reaction of anhydrous YbC13 with 2 equiv, of sodium 2,4,6-tri-tert-butylphenoxide (ArONa, Ar=C6H2-t-Bu3-2,4,6) and 2 equiv, of potassium diphenyl amide in THF afforded the first bis(aryloxo) amido-lanthanide complex of (ArO)2Yb(NPh2)2K(THF)4 (1). In 1, the ytterbium and potassium were bridged via diphenyl amido ligands.The ytterbium metal center was coordinated to two oxygen atoms of aryloxide ligands and two nitrogen atoms of diphenyl amido ligands in a conventional distorted tetrahedral fashion, while the potassium interacted in η^2-fashion with two phenyl rings of the diphenyl amido ligands besides four THF molecules. 1 displayed moderate catalytic activities for the polymerization of methyl methacrylate and acrylonitrile.