ORGANOAMIDO-LANTHANOIDS AND ARYLOXO-LANTHANOIDS .14. ORGANOMETALLIC COMPOUNDS OF THE LANTHANOIDS .106. SYNTHESIS AND CHARACTERIZATION OF COMPLEXES OF LANTHANOID PYRAZOLATES WITH 1,2-DIMETHOXYETHANE AND THE X-RAY STRUCTURES OF ETHANE-O-1)TRIS(3,5-DIPHENYLPYRAZOLATO)ERBIUM(III) AND )-MU-(1,2-DIMETHOXYETHANE-O-1-O-2)-NEODYMIUM(III)]

The complexes [Ln(Ph(2)pz)(3)(DME)(2)] and [Ln(tBu(2)pz)(3)(DME)] (Ln = La, Nd, Er; Ph(2)pzH = 3,5-diphenylpyrazole; tBu(2)pzH = 3,5-di-tert -butylpyrazole; DME = 1,2-dimethoxyethane) have been prepared by react ion of the lanthanoid metal with bis(pentafluorophenyl)mercury and the pyrazole in DME. The molecular structures of [Er(Ph(2)pz)(3)(DME)(2)] (3) and [Nd(tBu(2)pz)(3)(DME)](x) (5) have been determined by X-ray d iffraction. Complex 3 has nine-coordinate Er with three chelating Ph(2 )pz ligands and one chelating and one eta(1)-bound DME. There is a tri gonal prismatic arrangement of the oxygen donors and the centres of th e N-N bonds. 5 was found to be a linear polymer with transoid DME Liga nds bridging Nd(tBu(2)pz)(3) units in a novel manner. The centres of t he N-N bonds (which are essentially coplanar with Nd), and the oxygen donor atoms adopt an arrangement intermediate between trigonal-bipyram idal and square-pyramidal [O-Nd-O 153.5(2)degrees].