ORGANOAMIDO-LANTHANOIDS AND ARYLOXO-LANTHANOIDS .17. NOVEL LOW-COORDINATE LANTHANOID(II) AND LANTHANOID(III) ARYLOXIDE COMPLEXES - THE X-RAY STRUCTURES OF HENYLPHENOLATO)TRIS(TETRAHYDROFURAN)YTTERBIUM(II), OXYETHANE)BIS(2,6-DIPHENYLPHENOLATO)YTTERBIUM(II), AND OXYETHANETRIS(2,6-DIPHENYLPHENOLATO)YTTERBIUM(III) AND OXYETHANETRIS(2,6-DIPHENYLPHENOLATO)NEODYMIUM(III)

Reduction of [Yb(Odpp)(3)(THF)(2)] (HOdpp = 2,6-diphenylphenol THF = t etrahydrofuran) with ytterbium powder and mercury metal yields [Yb(Odp p)(2)(THF)(3)] (1) which on crystallization from DME gives [Yb(Odpp)(2 )(DME)(2)] (2) (DME = 1,2-dimethoxyethane). Crystallization of the rea ctant [Yb(Odpp)(3)(THF)(2)] from DME yields [Yb(Odpp)(3)(DME)] . (DME) (0.5) (3) and of [Nd(Odpp)(3)(THF)(2)] from DME/THF the analogous [Nd( Odpp)(3)(DME)] . (THF) (4). The X-ray crystal structure of 1 reveals d istorted trigonal bipyramidal five-coordinate ytterbium with axial Odp p ligands [O-Yb-O 164.6(3)(o)], and unsymmetrically distributed equato rial THF Ligands [O-Yb-O 137.5(3), 138.8(3), 83.7(4)(o)] owing to two close H(Ph)... Yb approaches (3.1-3.2 Angstrom). In 2, there is trigon al prismatic six-coordination with an Odpp ligand on each triangular f ace and DME ligands bridging the triangular faces. Both 3 and 4 have d istorted square planar five-coordination for the lanthanoid metals wit h an apical Odpp ligand and cisoid Odpp Ligands and a chelating DME in the square plane.