Systematic studies on the reactions of lanthanide trichlorides with Na[1,3-bis(trimethylsilyl) cyclopentadienyl]. Crystal structures of [1,3-(Me3Si)2C5H3]3Ln (LnLa, Nd, Gd, Dy)
作者:Zuowei Xie、Kwoli Chui、Zhixian Liu、Feng Xue、Zeying Zhang、Thomas C.W. Mak、Jie Sun
DOI:10.1016/s0022-328x(97)00489-0
日期:1997.12
Reflux of LnCl(3) with an excess amount of Na[(Me3Si)(2)C5H3] in THF and then in toluene gave two kinds of complexes dependent upon the size of the central metal, the tris ligand complexes of the type [(Me3Si)(2)C5H3](3)Ln (Ln = La, Nd, Sm, Gd or Dy) and the bis ligand complexes of the general formula [(Me3Si)(2)C5H3}(2)LnCl](2) (Ln = Gd, Dy, Y, Er or Yb). Neither THF coordinated nor THF ring-opened product was isolated. These compounds were fully characterized by elemental analyses, IR, MS and H-1 NMR (for diamagnetic metals) spectroscopy. The structures of the tris ligand complexes of La. Nd, Gd and Dy have been further confirmed by single-crystal X-ray diffraction analyses. Each of the three (Me3Si)(2)C5H3 ligands is eta(5)-bonded to the central lanthanide atom to form the trigonal planar geometry with an average (ring centroid)-metal-(ring centroid) bond angle of 120 degrees. The variations in the metal-carbon bond distances are consistent with the phenomenon of lanthanide contraction. (C) 1997 Elsevier Science S.A.