• Title/Summary/Keyword: 산소 ��칭

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Two Possible Space Groups of Ttis(tekaethylammonium) [bis(trimetaphosphate $\kappa^3O, O^', O^{"}$)] Vanadate(3-),$[V(P_3O_9)_2](NC_8H_{20})3$ (Tris(tetraethylammnnium) [bis(trimetaphosphate $\kappa^3O, O^', O^{"}$)] Vamdate(3-),$[V(P_3O_9)_2](NC_8H_{20})_3$,의 두가지 가능한 공간군)

  • 서일환;이진호
    • Korean Journal of Crystallography
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    • v.5 no.1
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    • pp.1-6
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    • 1994
  • Two possible space groups of the comfound, VP6N3018C24H:60, are: P 1, a=14.022(1), b=12.644(2), c= 12.640(1)A, a=8038(1), B=102.12(1), r=102.16(1), V=2124.1A3, Z=2, μ=0.47cm-1, d=1.46g/cm3, R=0.083 for 3350 independent reflections with Fo>4o IFI, and C2/c, a=19.32(2), b=16.32(2), c=14.02(1)A, B=105.98(5), β=105.98(5), V=4248.2A3, Z=4 R=0.083 for 1590 independent reflections with Fo>4c IFoI . In the space group P T, there are two monlecules in a unit cell. Vanadium atoms in the two monlecules occupy the two different special positions such that the complete monlecules are accomplished by the two independent center of symmetry. Therefore two different half molecules of bis(trimetaphosphate)vanadate and three molecules of tetraethylammonium are the asymmetric unit in a unit cell. In the space group C2/c, however, the vanadium atom is located at a special position with centrosymmetry, and a two-fold symmetry axis passes through C2/c, N2 and C25 atoms. Therefore the asymmrtic unit in a unit cell consists of a half molecule of bis(trimetaphosphate)vanadate and one and a half molecules of tetraethylammonium. All the molecular conformations in both space groups are very similar: six oxygen atoms coordinated to a vanadium atom in the bi s(trimetaphosphate)vanadate molecule form an octahedron and the four carbon atoms bonded to a nitrogen atom in the tetraethylammonium molecule are disordered so that the eight carbon atoms around nitrogen atom exhibit an irregular dodecahedral form.

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