SYNTHESIS AND CHARACTERIZATION OF TITANIUM COMPLEXES CONTAINING THE 1-(3-BUTENYL)-2,3,4,5-TETRAMETHYLCYCLOPENTADIENYL LIGAND

A series of titanium complexes containing the 1-(3-butenyl)-2,3,4,5-te tramethylcyclopentadienyl ligand C(5)Me(4)CH(2)CH(2)CH=CH2 (Cp(=)) hav e been synthesized and characterized. The dichloro complex Cp(2)(=)TiC l(2) was prepared by the reaction of LiCp(=) and TiCl3 in dimethoxyeth ane, followed by oxidation using lead dichloride. Cp(2)(=)TiCl(2) was converted into the dimethyl derivative Cp(2)(=)TiMe(2), the molecular structure of which was confirmed by an X-ray structural analysis, whic h showed it to be a peralkyl titanocene complex containing the two pen dent 3-butenyl side chains in the lateral positions of the bent metall ocene unit. The reaction of Cp(2)(=)TiMe(2) with B(C6F5)(3) was monito red by NMR spectroscopy. Cp(=)TiCl(3), which was used to synthesize Cp (=)CpTiCl(2) by reacting with LiCp, was prepared from the reaction bet ween Cp(=)SiMe(3) and TiCl4. Cp(=)CpTiCl(2) was further converted into Cp(=)CpTiMe(2) and Cp(=)CpTi(OTf)(2). A significantly improved method for the preparation of 1-(3-butenyl)-2,3,4,5-tetramethylcyclopentadie ne was developed.