139 resultados para -Er^3
Resumo:
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Resumo:
(~5-C_9H_7)_3LnOC_4H_8(Ln=NdGdEr),,(~5-C_9H_7)_3NdOC_4H_8(1)(~5-C_9H_7)_3GdOC_4H_8(2)(1)(2),P6_3,Z=2(1)a=b=1.1843(3)nm,c=1.0304(4)nm,V=1.25165(87)nm~3,D_c=1.49gcm~(-3),R=0.049;(2)a=b=1.1805(2)nm,c=1.0236(2)nm,V=1.23536(56)nm~3,D_c=1.54 gcm~(-3),R=0.023Nd-C=0.2812nm,Gd-C=0.2795nm;Nd-O=0.2557(21)nm,GdO=0.2459(13)nm
Resumo:
The complexes named in the title (eta-5-C9H7)3Ln.OC4H8 (Ln = Nd, Gd, Er) were synthesized by the reaction of anhydrous lanthanide trichlorides with indenyl potassium and cyclooctadienyl potassium (1:2:1 molar ratio) in THF. The complexes were characterized by elemental analysis, infrared and H-1-NMR spectroscopy, and mass spectrometry. In addition, the crystal structures of (eta-5-C9H7)3Nd.OC4H8 (1) and (eta-5-C9H7)3Gd.OC4H8 (2) were determined by an X-ray diffraction study. Complexes 1 and 2 belong to hexagonal space group P6(3) with unit cell parameters a = b = 11.843(3), c = 10.304(4) angstrom, V = 1251.7(9) angstrom-3, D(c) = 1.49 g.cm-3, Z = 2 for 1, and a = b = 11.805(2), c = 10.236(2) angstrom, V = 1235.4(6) angstrom-3 D(c) = 1.54 g.cm-3, Z = 2 for 2. The structures were solved by Patterson and Fourier techniques and refined by least-squares to final discrepancy indices of R = 0.049, R(w) = 0.053 using 925 independent reflections with I greater-than-or-equal-to 3-sigma(I) for 1, and R = 0.023, R(w) = 0.025 using 1327 independent reflections with I greater-than-or-equal-to 3-sigma(I) for 2. Coordination numbers for Nd3+ and Gd3+ are 10; the average bond lengths Nd-O and Gd-O are 2.557(21) and 2.459(13) angstrom, respectively. The structural studies showed the complexes to have 3-fold symmetry, but the THF molecule has no such symmetry; consequently the arrangement of carbon atoms in the THF molecule are disordered.
