CYANO DERIVATIVES OF BIS(CYCLOPENTADIENYL)TITANIUM(IV) - THE CRYSTAL AND MOLECULAR STRUCTURE OF U-OXO-BIS[BIS(CYCLOPENTADIENYL)CYANOTITANIUM(IV)], [(ETA(5)-C5H5)(2)TICN](2)O

By the reaction of KCN with Cp(2)TiCl(2) (Cp = eta(5)-C5H5) in boiling methanol, bis(cyclopentadienyl)methoxytitanium(IV) cyanide, Cp(2)Ti(O CH3)CN, is formed which in air is converted into the dinuclear oxygen- bridged derivative (Cp(2)TiCN)(2)O. By the same procedure, the bis(met hylcyclopentadienyl) analogue [MeCp(2)TiCN]O-2 has been obtained. An X -ray diffraction study of (Cp(2)TiCN)(2)O has shown that the CN group acts as a unidentate ligand with a Ti-C bond length of 2.158 Angstrom and a Ti-C-N bond angle of 177.7 degrees, very close to linearity. The Ti-O bond distance, 1.836 Angstrom, and the bond angle at the bridgin g O atom, 174.1 degrees, are normal. The ligands are arranged in a nea rly tetrahedral way around the Ti atoms. The structural results are co mpared to those for similar dinuclear titanium complexes.