PHOSPHORANEIMINATO COMPLEXES OF RARE-EART HS ELEMENTS - SYNTHESES ANDCRYSTAL-STRUCTURES OF [M-2(C5H5)(3)(NPPH3)(3)]CENTER-DOT-3C(7)H(8) WITH M = Y, DY, AND ER - MAGNETIC-PROPERTIES OF [DY-2(C5H5)(3)(NPPH3)(3)]CENTER-DOT-3C(7)H(8)

The title compounds have been prepared by reactions of the cyclopentad ienidchlorides [M(C5H5)(2)Cl](2) With LiNPPh3 in boiling toluene, and they were characterized by crystal structure determinations. All three compounds crystallize isotypicly with one another within the orthorho mbic space group Pbca with Z = 8. Two of the three phosphoraneiminato groups link the metal atoms via mu(2)-N atoms to almost planar M2N2 fo ur-membered rings. The third NPPh3- group is terminally bonded. The ma gnetic susceptibility of [DY2(C5H5)(3)(NPPh3)(3)] . 3C(7)H(8) has been determined (SQUID magnetometer) in the temperature range 1.7 K-300 K at magnetic fields between 0.01 T and 5 T. Calculations based on a cub ic ligand field model lead to a satisfactory simulation with reasonabl e ligand field parameters. The inclusion of isotropic intramolecular e xchange interactions in the model does not improve the fit, so that in the framework of the applied model no hints to a spin-spin coupling w ithin the dinuclear units are obtained.