SYNTHESIS AND CRYSTAL-STRUCTURE OF [(ETA(5)ETA(5)-C(5)H(4)PPH(2))TL](INFINITY) AND THE DIVALENT YTTERBIUM DERIVATIVE [(ETA(5)-C(5)H(4)PPH(2))(2)YB(DME)]

The complex [(diphenylphosphino)cyclopentadienyl]thallium [(eta(5):eta(5)-C(5)H(4)PPh(2))Tl](infinity) (1) and the divalent ytterbium compound [(eta(5)-C(5)H(4)PPh(2))(2)Yb(DME)] (2) (DME=dimethoxyethane) made from it have been synthesized and characterized by IR, H-1 NMR and P-31 NMR spectroscopy and X-ray diffraction studies. In the crystal 1, polymeric zigzag chains of alternating thallium ions and cyclopentadienyl rings form, with the neighboring chains were connected by the weak interactions between phosphorus and thallium atoms. In contrast, 2 is a neutral monomer with two dangling phosphorus atoms.