STUDIES ON ORGANOLANTHANIDE COMPLEXES .53. EFFECT OF RARE-EARTH-METALRADIUS ON THE MOLECULAR-STRUCTURE - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF BIS((2-METHOXYETHYL)CYCLOPENTADIENYL) RARE-EARTH-METAL CHLORIDES
Ct. Qian et al., STUDIES ON ORGANOLANTHANIDE COMPLEXES .53. EFFECT OF RARE-EARTH-METALRADIUS ON THE MOLECULAR-STRUCTURE - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF BIS((2-METHOXYETHYL)CYCLOPENTADIENYL) RARE-EARTH-METAL CHLORIDES, Inorganic chemistry, 33(15), 1994, pp. 3382-3388
The bis((2-methoxyethyl)cyclopentadienyl) rare earth metal chlorides (
CH3OCH2CH2C5H4)2LnCl [Ln = La (1), Pr (2), Nd (3), Sm (4), Gd (5), Dy
(6), Ho (7), Er (8), Tm (9), Yb (10), Lu (11), Y (12)] were synthesize
d by treating the respective rare earth metal trichlorides with 2 equi
v of ((2-methoxyethyl)cyclopentadienyl)sodium in THF. The new compound
s have been characterized by elemental analyses, MS, IR and NMR spectr
a, as well as X-ray diffraction analyses of 1, 6, and 10. 1 crystalliz
es from toluene in the monoclinic space group P2(1)/n (No. 14) with un
it cell parameters a = 8.726(1) angstrom, b = 12.367(1) angstrom, c =
14.562(3) k, beta = 93.90(9)-degrees, and V = 1567.8(2) angstrom3 with
Z = 4 for D(calcd) = 1.782 g cm-3 and R = 0.038 for 6771 independent
reflections with [I > 3sigma(I)]. 6 and 10 crystallize from THF in the
orthorhombic space group Pnma (No. 62) with unit cell parameters a =
12.242(3) angstrom, b = 11.723(6) angstrom, c = 11.293(2) angstrom, an
d V = 1620.7(2) angstrom3 with z = 4 for D(calcd) = 1.821 g cm-3 (6) a
nd a = 12.207(4) angstrom, b = 11.705(3) angstrom, c = 11.176(2) angst
rom, and V = 1596.8(6) angstrom3 with z = 4 for D(calcd) = 1.892 g cm-
3 (10), respectively. Least-squares refinement led to a final R value
of 0.027 for 1199 independent reflections [I > 3sigma(I)] for 6 and fo
r 0.037 for 1118 independent reflections [I > 3sigma(I)] for 10. The X
-ray structure analyses show that complex 1 is dimer and the formal co
ordination number of lanthanum is 10, but complexes 6 and 10 are monom
eric; the formal coordination number of dysprosium and ytterbium is ni
ne. It indicates that the molecular structure of those chlorides depen
ds on the radius of central metal.