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Open Access Publications from the University of California

Scholarly Works (3 results)

  • Article
  • Peer Reviewed
UC Irvine Previously Published Works (2020)
Studies of the coordination chemistry between the di-phenyl-amide ligand, NPh2, and the smaller rare-earth Ln III ions, Ln = Y, Dy, and Er, led to the structural characterization by single-crystal X-ray diffraction crystallography of both solvated and unsolvated complexes, namely, tris-(di-phenyl-amido-κN)bis-(tetrahydro-furan-κO)yttrium(III), Y(NPh2)3(THF)2 or [Y(C12H10N)3(C4H8O)2], 1-Y, and the erbium(III) (Er), 1-Er, analogue, and bis-[μ-1κN:2(η6)-di-phenyl-amido]-bis-[bis-(di-phenyl-amido-κN)yttrium(III)], [(Ph2N)2Y(μ-NPh2)]2 or [Y2(C12H10N)6], 2-Y, and the dysprosium(III) (Dy), 2-Dy, analogue. The THF ligands of 1-Er are modeled with disorder across two positions with occupancies of 0.627 (12):0.323 (12) and 0.633 (7):0.367 (7). Also structurally characterized was the tetra-metallic ErIII bridging oxide hydrolysis product, bis-(μ-di-phenyl-amido-κ2 N:N)bis-[μ-1κN:2(η6)-di-phenyl-amido]-tetra-kis-(di-phenyl-amido-κN)di-μ3-oxido-tetra-erbium(III) benzene disolvate, {[(Ph2N)Er(μ-NPh2)]4(μ-O)2}·(C6H6)2 or [Er4(C12H10N)8O2]·2C6H6, 3-Er. The 3-Er structure was refined as a three-component twin with occupancies 0.7375:0.2010:0.0615.
    Cover page: Synthesis and crystallographic characterization of di­phenyl­amide rare-earth metal complexes Ln(NPh2)3(THF)2 and [(Ph2N)2 Ln(μ-NPh2)]2Creative Commons 'BY' version 4.0 license
    • Article
    • Peer Reviewed
    UC Irvine Previously Published Works (2017)
    Cp'2Ln(THF)2 metallocenes (Cp' = C5H4SiMe3) react with 2.2.2-cryptand (crypt) to form Ln2+-in-crypt complexes, [Ln(crypt)(THF)][Cp'3Ln]2 (Ln = Sm, Eu) and [Yb(crypt)][Cp'3Yb]2, that contain Ln2+ ions surrounded only by neutral ligands. A bimetallic, mixed-ligand metallocene/opened-crypt complex of Sm2+, [Sm(C16H32N2O6-κ2O:κ2O')SmCp''2], was obtained by KC8 reduction of Cp''2Sm(THF) [Cp'' = C5H3(SiMe3)2] in the presence of crypt.
      Cover page: Synthesis of rare-earth-metal-in-cryptand dications, [Ln(2.2.2-cryptand)] 2+ , from Sm 2+ , Eu 2+ , and Yb 2+ silyl metallocenes (C 5 H 4 SiMe 3 ) 2 Ln(THF) 2Creative Commons 'BY' version 4.0 license
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2015)
      A new option for stabilizing unusual Ln2+ ions has been identified in the reaction of Cp'3Ln, 1-Ln (Ln = La, Ce; Cp' = C5H4SiMe3), with potassium graphite (KC8) in benzene in the presence of 2.2.2-cryptand. This generates [K(2.2.2-cryptand)]2[(Cp'2Ln)2(μ-η6:η6-C6H6)], 2-Ln, complexes that contain La and Ce in the formal +2 oxidation state. These complexes expand the range of coordination environments known for these ions beyond the previously established examples, (Cp''3Ln)1- and (Cp'3Ln)1- (Cp'' = C5H3(SiMe3)2-1,3), and generalize the viability of using three anionic carbocyclic rings to stabilize highly reactive Ln2+ ions. In 2-Ln, a non-planar bridging (C6H6)2- ligand shared between two metals takes the place of a cyclopentadienyl ligand in (Cp'3Ln)1-. The intensely colored (ε = ∼8000 M-1 cm-1) 2-Ln complexes react as four electron reductants with two equiv. of naphthalene to produce two equiv. of the reduced naphthalenide complex, [K(2.2.2-cryptand)][Cp'2Ln(η4-C10H8)].
        Cover page: Isolation of +2 rare earth metal ions with three anionic carbocyclic rings: bimetallic bis(cyclopentadienyl) reduced arene complexes of La2+ and Ce2+ are four electron reductants.
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