SYNTHESIS AND CHARACTERIZATION OF ORGANOMOLYBDENUM AND ORGANOTUNGSTEN HALIDES CONTAINING THE ETA(5)-PENTABENZYLCYCLOPENTADIENYL LIGAND ETA(5)-BZ(5)C(5)M(CO)(3)X (M=MO, W X=CL, BR, I) - THE X-RAY MOLECULAR-STRUCTURE OF ETA(5)-BZ(5)C(5)MO(CO)(3)I

An improved synthetic procedure for pentabenzylcyclopentadiene Bz(5)C(5)H was developed. Six new organomolybdenum and organotungsten halides eta(5)-Bz(5)C(5)M(CO)(3)X (M=Mo, W;X=Cl,Br,I) were synthesized through the reaction of eta 5-Bz(5)C(5)M(CO)(3)Li (derived from Bz(5)C(5),H, n-BuLi and M(CO)(6)) with PCI3, PBr3, or I-2 and characterized by elemental analysis, IR and H-1 NMR spectroscopy. The structure of eta(5)-Bz(5)C(5)Mo(CO)(3)I was determined by single-crystal X-ray diffraction techniques. It crystallized in the monoclinic space group P2(1)/c with cell parameters a=13.294(4), b=15.147(4), c=19.027(3) Angstrom, beta=108.32(2)degrees, V=3637(2) Angstrom(3), Z=4 and D-x=1.50 g cm(-3). The final R value was 0.035 for 4564 observed reflections.