Intermetallics as Zintl phases: Yb2Ga4Ge6 and RE3Ga4Ge6 (RE = Yb, Eu): Structural response of a [Ga4Ge6]4- framework to reduction by two electrons

Marina A. Zhuravleva, James Salvador, Daniel Bilc, Subhendra D. Mahanti, John Ireland, Carl R. Kannewurf, Mercouri G. Kanatzidis

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21 Citations (Scopus)

Abstract

Two new intermetallic compounds, Yb2Ga4Ge6 and Yb3Ga4Ge6, were obtained from reactions in molten Ga. A third compound, Eu3Ga4Ge6, was produced by direct combination of the elements. The crystal structures of these compounds were studied by single-crystal X-ray diffraction. Yb 2Ga4Ge6 crystallizes in an orthorhombic cell with a=4.1698(7), b= 23.254(4), c=10.7299(18) A in the polar space group Cmc21. The structure of RE3Ga4Ge6 is monoclinic, space group C2/m, with cell parameters a= 23.941(6), b=4.1928(11), C= 10.918(3) Å, β=91.426(4)° for RE=Yb, and a=24.136(2), b=4.3118(4), c=11.017(1) Å, β=91.683(2)° for RE=Eu. The refinement [I>2σ(I)] converged to the final residuals R 1/wR2=0.0229/0.0589, 0.0411/0.1114, and 0.0342/0.0786 for Yb2Ga4Ge6, Yb3Ga4Ge 6, and Eu3Ga4Ge6, respectively. The structures of these two families of compounds can be described by a Zintl concept of bonding, in which the three-dimensional [Ga4Ge 6]n- framework serves as a host and electron sink for the electropositive RE atoms. The structural relation of RE3Ga 4Ge6 to of Yb2Ga4Ge6 lies in a monoclinic distortion of the orthorhombic cell of Yb2Ga 4Ge6 and reduction of the [Ga4Ge6] network by two electrons per formula unit. The results of theoretical calculations of the electronic structure, electrical transport data, and thermochemical and magnetic measurements are also reported.

Original languageEnglish
Pages (from-to)3197-3208
Number of pages12
JournalChemistry - A European Journal
Volume10
Issue number13
DOIs
Publication statusPublished - Jul 5 2004

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Keywords

  • Flux synthesis
  • Gallium
  • Germanium
  • Lanthanides
  • Zintl phases

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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