124206-21-9Relevant academic research and scientific papers
Four-and five-co-ordinate lanthanide (II) aryloxides: X-ray structures of the bis(2,6-di-t-butyl-4-methylphenoxo)ytterbium(II) complexes [Yb(OAr) 2(L)2] and [Yb(OAr)2(L′)3] [Ar=C6H2But
Deacon, Glen B.,Hitchcock, Peter B.,Holmes, Stephen A.,Lappert, Michael F.,MacKinnon, Peter,Newnham, Russell H.
, p. 935 - 937 (1989)
General methods for the preparation of hydrocarbon-soluble, monomeric ytterbium (II) aryloxides are described {Yb+2TIOAr, or [Yb(NR2) 2(OEt2)2]+2ArOH;R=SiMe3, Ar=C 6H2But/s
The First Structurally Authenticated Divalent Lanthanide Stannyl Derivative
Cloke, F. Geoffrey N.,Dalby, Christopher I.,Hitchcock, Peter B.,Karamallakis, Helen,Lawless, Gerard A.
, p. 779 - 781 (1991)
The reaction between YbI2 and Kt)3> affords the diamagnetic ytterbium bis-stannyl derivative 1 (Nep = 2,2-dimethylpropyl and thf = tetrahydrofuran) which has been characterised by multinuclear NMR spectroscopy (119Sn and 171Yb) and X-ray crystallography: reaction of 1 with two equivalents of ArOH (ArOH = 2,6-di-tert-butyl-4-methylphenol) or C5Me5H results in the elimination of Sn(CH2But)3H to afford the known complexes and respectively whereas the reaction with one equivalent of ArOH or C5Me5 resultsin the formation of the novel mixed ligand complexes t)3>(thf)2> and t)3>(thf)2>.
Reactivity of trimethylaluminum with lanthanide aryloxides: Adduct and tetramethylaluminate formation
Fischbach, Andreas,Herdtweck, Eberhardt,Anwander, Reiner,Eickerling, Georg,Scherer, Wolfgang
, p. 499 - 509 (2008/10/08)
The reaction of various highly substituted lanthanide(III) and -(II) aryloxide complexes with trimethylaluminum (TMA) was investigated. The solvent-free, π-arene-bridged dimers [Ln(OAriPr,H)3]2, derived from the ortho-iPr2-substituted aryloxide ligand OC6H3iPr2-2,6, form bis-TMA adduct complexes, Ln(OAriPr,H)3(AlMe3)2, for the metal centers yttrium, samarium, and lanthanum. Homoleptic monomeric Ln(OAr)3, featuring a large La center and sterically bulkier ortho-tBu2-substituted aryloxide ligands, afford the mono-TMA adducts La(OArtBu,R)3(AlMe3) (R = H, Me). The hetero-bridged moieties "Ln(μ-OAr)(μ-Me)Al" of these adduct complexes are rigid in solution, while at ambient temperature the exchange of bridging and terminal aluminum methyl groups is fast on the NMR time scale. Monomeric Ln(OArtBu,R)3 (R = H, Me, tBu) of the smaller rare-earth-metal centers yttrium and lutetium react with TMA to give mono(tetramethylaluminate) complexes of the type (ArtBu,RO)2Ln[(μ-Me)2AlMe2]. The heteroleptic Cp=supported complex (C5Me5)Y(OArtBu,H)2 also produced a tetramethyl-aluminate complex, namely (C5Me5)Y(OArtBu,H)[(μ-Me)2 AlMe2], in the TMA reaction. The solvated aryloxide complexes Ln(OAr)2(THF)x (x = 1, 2), featuring the divalent rare-earth-metal centers ytterbium and samarium, yield the bis-TMA adduct complexes Ln[(μ-OArtBu,R)-(μ-Me)AlMe2]2. However, it was found that the generation of homoleptic hexane-insoluble [Ln(AlMe4)2]n is an important reaction pathway governed by the size (oxophilicity) of the metal center (Yb ? Sm), the amount of TMA, the reaction period, and the substituents of the aryloxide ligand (OAriPr,H ? OArtBu,H > OArtBu,Me ? OArtBu,tBu). For the Ln(III) aryloxide complexes, peralkylated complexes Ln(AlMe4)3 were detected only in the presence of the least bulky ligand, OAriPr,H. Various mechanistic scenarios are depicted on the basis of the rare-earth-metal species identified, including byproducts such as [Me2Al(μ-OAr)]2, and of the interactivity of rare-earth alkoxide complexes with trialkylaluminum compounds known from the literature. the complexes Y(OC6H3iPr2-2,6) [(μ-OC6H3iPr2-2,6)(μ-Me) AlMe2]2 and Ln(OC6H3tBu2-2,6)2[(μ- Me)2AlMe2] (Ln = Y, Lu) have been characterized by X-ray diffraction structure determinations.
