FULVALENE DERIVATIVES OF TITANIUM - X-RAY STRUCTURES OF [(TICL2)2(MU-O)(MU-ETA-5-ETA-5-C10H8)] AND [(TI(CH2C6H5)3)2(MU-ETA-5-ETA-5-C10H8)]

Dithalliofulvalene and bis(trimethylsilyl)fulvalene were used as alkylating reagents to transfer the fulvalene group to TiCl4, leading to [(TiCl3)2(mu-eta5:eta5-C10H8)] (1; 30% yield). This extremely moisture-sensitive compound is quantitatively hydrolyzed to the mu-oxo dinuclear complex [(TiCl2)2(mu-O)(mu-eta5:eta5-C10H8)] (2) when the reaction to synthesize 1 is carried out in wet toluene or chloroform. The transformation of 2 into 1 can also be done by reacting the mu-oxo derivative with AlEtCl2 in toluene. Alkylation of 1 with [Mg(CH2Ph)2].THF led to [{Ti(CH2Ph)3}2(mu-eta5:eta5-C10H8)] (3; 97% yield). The crystal structures of 2 and 3 have been determined by X-ray diffraction methods. Crystals of 2 are monoclinic, space group P2(1)/c, with Z = 4 in a unit cell of dimensions a = 9.305 (3) angstrom, b = 12.387 (4) angstrom, c = 12.821 (4) angstrom, and beta = 110.31 (2)-degrees. Crystals of 3 are monoclinic, space group P2(1)/n, with Z = 2 in a unit cell of dimensions a = 16.976 (6) angstrom, b = 11.022 (5) angstrom, c = 11.238 (4) angstrom, and beta = 101.15 (2)-degrees. Both structures were solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least squares on the basis of 1662 (2) and 2126 (3) observed reflections to R and R(W) values of 0.0397 and 0.0482 (2) and 0.0490 and 0.0609 (3), respectively. In both compounds each fulvalene cyclopentadienyl ring is eta5-bound to one titanium atom. The remaining coordination sites of titanium are occupied by two chlorines and one bridging oxygen in 2 or by three benzyl ligands in 3, each showing a different bonding system.