FULVALENE CYCLOPENTADIENYL TITANIUM AND ZIRCONIUM(III) AND ZIRCONIUM(IV) COMPLEXES - X-RAY CRYSTAL-STRUCTURE OF [(TI(ETA-5-C5H5)CL)2(MU-O)(MU-ETA-5-ETA-5-C10H8)]

The reaction of the fulvalene titanium(III) hydride [{Ti(eta5-C5H5)(mu-H)}2(mu-eta5-eta5-C10H8)] (1) with chlorine leads to [{Ti(eta5-C5H5)(mu-Cl))2(mu-eta5-eta5-C10H8)] (3) and [{Ti(eta5-C5H5)Cl2}2(mu-eta5-eta5-C10H8)] (4). The reaction of 3 with azobenzene, in wet toluene, gives [{Ti(eta5-C5H5)Cl}2(mu-O)(mu-eta5-eta5-C10H8)] (5) and 1,2-diphenyl hydrazine. The alkylation of 4 and the analogous zirconium complex [{Zr(eta5-C5H5)Cl2}2(mu-eta5-eta5-C10H8)] (2) with LiCH2SiMe3 or LiCH3 permits isolation of the tetraalkyl derivatives [{M(eta5-C5H5)(CH2SiMe3)2}2(mu-eta5-eta5-C10H8)] (M = Ti (6); Zr (8)) and [{Ti(eta5-C5H5)(CH3)2}2(mu-eta5-eta5C10H8)] (7). All the new fulvalene compounds were characterized by IR, and H-1 and C-13 NMR spectroscopy, and mass spectra and 5 by X-ray diffraction. The structure of 5 is very similar to that of the comparable Ti(IV) compound [{Ti(eta5-C5H5)2Cl}2(mu-O)] except for the smaller Ti-O-Ti angle (159.4-degrees against 173.81-degrees) and a significant deviation from linearity.