SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF ETHOXYMETHYL)PHENYLDICYCLOPENTADIENYLTITANIUM(III)

Reaction of bis(2-methoxymethylphenyl)magnesium (1a) with Cp(2)TiCl(2) in THF affords Cp(2)Ti[2-CH3OCH2C6H4] (3) and 2,2'-bis(methoxymethyl) biphenyl in high yield. The crystal structure of 3 has been determined and is the first structure of a Ti(III) compound in which the Ti atom is intramolecularly coordinated by oxygen. Two chemically identical a nd conformationally only slightly different residues were found to be present in the unit cell of 3. Compound C18H19OTi (3) crystallizes in the monoclinic space group Pc (no. 7) with a = 13.0248(8), b = 7.7769( 5), c = 14.8491(7)Angstrom, beta = 106.448(4)degrees, V = 1442.55(15)A ngstrom(3), Z = 4. The structure refinement converged to R1 = 0.0478 f or 4891 F-o)4 sigma(F-o) and wR2 = 0.0968 for all 6600 unique data, S = 1.010. The structure shows a pseudotetrahedral coordination around t he Ti atom by two eta(5)-cyclopentadienyl groups, one carbon of the ar yl ligand (Ti-C 2.19 Angstrom) and an oxygen atom of the methoxymethyl group. The Ti-O distance of 2.20 Angstrom is 1.48 Angstrom shorter th an the expected van der Waals distance, which indicates a strong inter action between Ti and O. Reaction of bis(2-N,N-dimethylaminomethylphen yl)magnesium (1b) and Cp(2)TiCl(2) affords in a similar fashion Cp(2)T i[2-(CH3)(2)NCH2C6H4] (4) and 2,2'-bis(N,N-dimethylaminomethyl)bipheny l.