Reaction Of YbCl3 Research Articles

Rare‐Earth Complexes Coordinated by ansa‐Bis(amidinate) Ligands with m‐Phenylene, 2,6‐Pyridinediyl, and SiMe2 Linkers

The salt‐metathesis reactions of anhydrous LnCl3 (Ln = Y, Er) with [1,3‐C6H4{NC(Ph)NSiMe3}2Li2(thf)2]2 (1; thf = tetrahydrofuran) in a 2:1 molar ratio in thf afford tris(amidinate) complexes [(1,3‐C6H4{NC(Ph)NSiMe3}2)3Y(thf)Y(µ‐Cl)Li(thf)3] (3) and [(1,3‐C6H4{NC(Ph)NSiMe3}2)3Er2(µ‐Cl)Li(thf)3] (4), which feature bridging coordination of the amidinate ligands to two Ln3+ ions. The reactions of the dilithium derivative of the related bis(amidine) with a 2,6‐pyridinediyl linker, [2,6‐C5H3N{NC(tBu)N(2,6‐Me2C6H3)}2]2–, with LnCl3 (Ln = Y, Er) result in the formation of mononuclear chlorido bis(ligand) ate complexes [{(2,6‐C5H3N)(NC{tBu}N{2,6‐Me2C6H3})2}({2,6‐C5H3N}{NC(tBu)N(2,6‐Me2C6H3)}{NC(tBu)NH(2,6‐Me2C6H3)})LnCl][Li(dme)3] [Ln = Y (5), Er (6); dme = 1,2‐dimethoxyethane]. The Ln3+ ions in these complexes are coordinated by one dianionic tridentate amidopyridinate–amidinate ligand, and the second ligand is a monoanionic amidopyridinate. The reaction of YbCl3 with [(Me2Si{NC(Ph)N(2,6‐iPr2C6H3)}2)2Li3][Li(thf)4], which contains a short SiMe2 linker, in a 2:1 molar ratio in thf afforded the bis(amidinate)chloridoytterbium complex [(Me2Si{NC(Ph)N(2,6‐iPr2C6H3)}2)2(Yb2Cl)(µ‐Cl)2Li(thf)3] (8). The magnetic properties of 4 were investigated through superconducting quantum interference device (SQUID) magnetometry.

Synthesis, Structure, and Catalytic Behavior of Ytterbium Complexes Derived from a Linked Bis(β‐ketoiminato) Ligand

AbstractYtterbium complexes supported by a linked bis(β‐ketoiminato) ligand, N,N′‐ethylenebis(benzoylacetoimine) (H2L), were synthesized and their catalytic behavior was explored. The reaction of YbCl3 with 1 equiv. of LLi2 afforded the mononuclear ytterbium chloride LYbCl(THF)2 (1) in high yield. Complex 1 can be used as starting material to prepare β‐ketoiminate‐ytterbium derivatives. Treatment of complex 1 with NaN(SiMe3)2 produced the dimeric ytterbium amide {LYb[N(SiMe3)2]}2 (2), while the similar reaction of complex 1 with NaOAr (ArO = 2, 6‐tBu‐4‐MeC6H2O) led to the mononuclear ytterbium aryloxide LYbOAr(THF) (3). The three complexes were well detected by elemental analysis and single‐crystal X‐ray analysis. It was found that complexes 2 and 3 can initiate the ring‐opening polymerization of ϵ‐caprolactone with moderate activity.

LiYbCl4(THF)4

The title compound, di-μ-chlorido-dichlorido-1κ2 Cl-tetra­kis­(tetra­hydro­furan)-1κ2 O,2κ2 O-lithiumytterbium(III), [LiYbCl4(C4H8O)4], was prepared by the reaction of YbCl3(THF)3 with LiCl in THF (THF is tetra­hydro­furan). The central motif of the structure is a Yb(μ-Cl)2Li ring. The Yb atom is hexa­coordinated to four Cl atoms and two THF mol­ecules oriented in a trans fashion. The Li atom has a tetra­hedral environment and is coordinated to two Cl atoms and two THF mol­ecules. No inter­molecular inter­actions other than van der Waals forces were observed. Two of the THF mol­ecules are disordered over two positions.

Deprotonation of β‐Diketiminate in Sterically Demanding β‐(Diketiminato)lanthanide Complexes: Influence of Lanthanide Metals

AbstractAttempted synthesis of tris(β‐diketiminato)lanthanide complexes [Ln(L)3] (L = [{N(C6H3Me2‐2,6)C(Me)}2CH]) resulted in ligand deprotonation, and different outcomes depending on the central metal used were observed. Reaction of YbCl3 with NaL (3 equiv.) afforded the five‐membered cyclometalated ytterbium β‐diketiminate complex [Yb(L)(L)dep] (1). The same reaction with LnCl3 (Ln = Nd, Sm, and Er) gave the new complexes composed of one normal L and one deprotonated neighboring benzazacyclopentane ligand derived from deprotonation of the 2‐methyl group followed by an attack of thecarbon atom on the β‐diketiminate backbone, [Ln(L)(L)dep′(thf)] [Ln = Nd (2), Sm (3), and Er (4)]. The bonding mode in the {Ln(L)dep′} moiety was also found to depend on the central metal ions.

Synthesis and properties of bis(indenyl) derivatives of ytterbium and lutetium. Molecular structures of the complexes (C9H7)2Ln(μ-Cl)2Li(Et2O)2 (Ln = Yb, Lu) and [(C9H7)2YbCl2][Li(DME)3

The heterobimetallic bis(indenyl) chloride complexes of ytterbium and lutetium (C9H7)2Ln(μ-Cl)2Li(Et2O)2 (Ln = Yb or Lu) were synthesized by the metathesis reaction of LnCl3 with two equivalents of indenyllithium in diethyl ether. In the case of ytterbium, the analogous reaction in 1,2-dimethoxyethane afforded the ionic complex [(C9H7)2YbCl2]−[Li(DME)3]+. The reaction of YbCl3 with indenylpotassium in a molar ratio of 1: 2 in THF is accompanied by reduction of the metal atom to give the bis(indenyl) derivative of YbII, (C9H7)2Yb(THF)2.

Synthesis, Reactivity, and Structural Characterization of Sodium and Ytterbium Complexes Containing New Imidazolidine-Bridged Bis(phenolato) Ligands

A new imidazolidine-bridged bis(phenol) [ONNO]H2 ([ONNO]H2=1,4-bis(2-hydroxy-3,5-di-tert-butyl-benzyl)imidazolidine) was prepared in relatively high yield by Mannish reaction of 2,4-di-tert-butylphenol, formaldehyde, and ethylenediamine in a 2:3:1 molar ratio. Reaction of the bis(phenol) with NaH in THF, after workup, afforded the sodium bis(phenolate) {[ONNO]Na2(THF)2}2.2THF (1) as a dimeric tetranuclear complex in an almost quantitative yield. Reaction of YbCl3 with complex 1 in a 2:1 molar ratio in THF, in the presence of HMPA, produced the desired bis(phenolate) ytterbium dichloride as bimetallic complex [ONNO]{YbCl2(HMPA)}2.2.5C7H8 (2). Complex 2 can be used as a precursor for the synthesis of ytterbium derivatives by salt metathesis reactions. Reaction of complex 2 with NaOiPr in a 1:2 molar ratio in THF led to the formation of bimetallic alkoxide [ONNO]{Yb(mu-OiPr)Cl(HMPA)}2.THF (3). However, the residual chlorine atoms in complex 3 are inactive for the further substituted reaction. Further study revealed that the bulkiness of the reagent has profound effect on the outcome of the reaction. Complex 2 reacted with bulky NaOAr (ArO=2,6-di-tert-butyl-4-methylphenoxo) or NaNPh2 in a 1:2 molar ratio under the same reaction conditions, after workup, to give the ligand redistributed products, (ArO)2YbCl(HMPA)2 (4) and [ONNO]YbCl(HMPA)2 (5) for the former and complexes 5 and (Ph2N)2YbCl(HMPA)2 (6) for the latter. If the molar ratio of complex 2 to NaNPh2 decreased to 1:4, the expected ligand redistributed products [ONNO]YbNPh2(HMPA) (7) and (Ph2N)3Yb(HMPA)2.C7H8 (8) can be isolated in high yields. All of the complexes were well characterized, and the definitive molecular structures of complexes 1-4, 7, and 8 were provided by single-crystal X-ray analysis.

A microporous coordination polymer with 1-D channels constructed from a basic reaction system

A ytterbium coordination polymer, {[Yb2(OH)2(atpt)2]·0.5H2O} n , (atpt = 2-aminoterephthalate) was synthesized by using the reaction of YbCl3·6H2O with 2-aminoterephthalic acid under hydrothermal condition and structurally characterized by single-crystal X-ray diffraction method. The Yb(III) complex crystallizes in the monoclinic system P2/c with a = 13.1306(9) A, b = 7.8049(5) A, c = 21.5601(12) A, β = 111.481(3)°, V = 2056.1(2) A3, Z = 4. There are two crystallographically independent Yb3+ ions in the crystal, in which one is seven-coordinate, the other is eight-coordinate, and both of them are in oxygen environments. The ligand atpt adopts two coordination modes, bis(bridging bidentate) and bis(chelating and bridging tridentate). In addition, every hydroxyl group adopts μ3-O mode linking three Yb3+ ions. It is through the linkage of atpt and hydroxyl group that ytterbium ions are linked together to form a 3-D structure with an open metal–organic framework.

Ytterbium and samarium bis(diphosphanylamides): syntheses and structures of lanthanide complexes having two [(Ph2P)2N]- ligands in the coordination sphere.

Bis(diphosphanylamide) complexes of the lanthanides have been synthesized. Two approaches to obtain these compounds are shown. Reaction of YbCl3 with a slight excess of [K(THF)n][N(PPh2)2] gives [((Ph2P)2N)2 YbCl(THF)2], which can be further reacted with K(C5Me5) to give the corresponding pentamethylcyclopentadienyl complex [((Ph2P)2N)2Yb(C5Me5)]. In a second approach to bis(diphosphanylamide) complexes of the lanthanides, Na(C(5)H(5)) was treated with SmCl3 to generate [(C5H5)SmCl2(THF)3] in situ. Further reaction with 2 equiv of [K(THF)n][N(PPh2)2] gave the desired complex [((Ph2P)2N)2Sm(C5H5)(THF)].

Synthesis, Structure, and Catalytic Behavior of rac-1,1‘-(3-Oxapentamethylene)-Bridged Bis(indenyl) ansa-Lanthanidocenes

A series of chiral 1,1‘-(3-oxapentamethylene)-bridged bis(indenyl) ansa-lanthanidocenes have been high stereoselectively synthesized. The reaction of YbCl3 with O(CH2CH2C9H6K)2 in THF provided a rac/meso mixture of [O(CH2CH2C9H6)2]YbCl(THF); the major diastereomer formed is racemic. The rac-[O(CH2CH2C9H6)2]YbCl(THF) (1) was isolated after recrystallization of a rac/meso mixture of [O(CH2CH2C9H6)2]YbCl(THF) in THF. Direct amidation (or alkylation) of the rac/meso lanthanidocene chloride mixtures in toluene provided solely pure racemic ansa-lanthanidocene amides [O(CH2CH2C9H6)2]LnN(SiMe3)2 (Ln = Y (2), Pr (3), Nd (4), Yb (5), Lu (6)) and pure racemic ansa-lanthanidocene hydrocarbyls [O(CH2CH2C9H6)2]LnCH2SiMe3 (Ln = Dy (7), Yb (8)). The structures of 1 and 5 were determined by X-ray diffraction. The amide and hydrocarbyl complexes are efficient single-component catalysts for methyl methacrylate polymerization. The effects of solvent and reaction temperature on the polymerization were studied. Very high molecular weight (Mn > 106) iso-rich poly(MMA) was obtained at lower temperature, while low molecular weight moderately syndiotactic poly(MMA) was obtained at higher temperature. The polymerization behavior is proposed to be associated with rac/meso interconversion of the active center.

Exo-nido- versus closo-Lanthanacarboranes. Synthesis and Structure of exo-nido-[(C6H5CH2)2C2B10H10]Ln(DME)3, [exo-nido-{(C6H5CH2)2C2B9H9}Ln(THF)3]2 (Ln = Sm, Yb), and closo-exo-[(C6H5CH2)2C2B10H10]4Sm2Na3

Treatment of LnI2 with 1 equiv of K2[(C6H5CH2)2C2B10H10] in THF at room temperature gave, after recrystallization from DME, the monomeric exo-nido-[(C6H5CH2)2C2B10H10]Ln(DME)3 (Ln = Sm (1), Yb (2)). They can react with another equivalent of Na2[(C6H5CH2)2C2B10H10] to afford closo-exo-[(C6H5CH2)2C2B10H10]4Ln2Na4(THF)2 (Ln = Sm (4), Yb (5)). Reaction of YbCl3 with 2 equiv of K2[(C6H5CH2)2C2B10H10] in THF/DME yielded 2, while treatment of SmCl3 with 2 equiv of K2[(C6H5CH2)2C2B10H10] in THF generated a novel cluster closo-exo-[(C6H5CH2)2C2B10H10]4Sm2Na3 (3). LnI2 reacted with 2 equiv of Na2[(C6H5CH2)2C2B9H9] in THF to produce the dimeric [exo-nido-{(C6H5CH2)2C2B9H9}Ln(THF)3]2 (Ln = Sm (6), Yb (7)). These new compounds were fully characterized by spectroscopy and elemental analyses. The solid-state structures of 1−3, 6, and 7 have been further confirmed by single-crystal X-ray analyses. This study indicates that steric factors dominate the formation of exo-nido-lanthanacarboranes. In case the substituents are ...

Synthesis and structures of homoleptic 2-methylpropane-2-thiolate complexes of samarium and ytterbium

The homoleptic 2-thiolate complexes [Li(tmeda)]3[Ln(SBut)6(Ln = Yb 1 and Sm 2 have been synthesized and structurally charecterized; 1 from the reaction of YbCl3 or YbI2(thf)x with LiSBut and 2 from Sml2(thf)x and LiSBut, in the presence of N,N,N′,N′-tetramethylethylenediamine (tmeda; thf = tetrahydrofuran).

PREPARATION AND STRUCTURE OF THE [YbCl2·15-CROWN-5]+CATION, AN EXAMPLE OF SEVEN-COORDINATE YTTERBIUM

Abstract The complex [YbCl2·15-crown-5][AlCl2Me2] has been prepared by the reaction of YbCl3, 15-crown-5, and AlMe3 (1:1:4) in toluene. The colourless, air-sensitive crystals belong to the orthorhombic space group Pnma with a = 11.313(7), b = 10.907(5), c = 17.716(7) A, and Dc = 1.81 g cm−3 for Z = 4. The structure was refined to R = 0.048 based on 1502 observed reflection. The Yb atom is displaced 0.20 A from the plane of the crown ether, and the Yb–O bond distance range from 2.23–2.32 A.