ORGANOLANTHANOIDS .18. THE SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF DI[MU-CHLOROBIS(DIPHENYLPHOSPHINO-ETA(5)-CYCLOPENTADIENYL)YTTERBIUM(III)]

Reaction of the divalent phosphinoytterbocene Yb(C(5)H(4)PPh(2))(2)(THF) (THF = tetrahydrofuran) with mercuric chloride in THF or toluene yields mercury metal and the lanthanoid(III) complex Yb(C(5)H(4)PPh(2))(2)Cl. An X-ray crystal structure of the compound revealed the presence of two independent chloride-bridged dimers (one centrosymmetric, one non-centrosymmetric, in a ratio of 1:2) with uncoordinated Ph(2)P groups and pseudo-tetrahedral eight coordination (two eta(5)-C(5)H(4)PPh(2) and two mu-Cl ligands) at ytterbium. The dimers differ in the arrangement (syn, anti) of the Ph(2)P groups. Solution spectroscopic data suggest that there is P-Yb bonding in toluene.