NEW ANILINO TROPONE-BASED TITANIUM COMPLEXES: SYNTHESIS, CHARACTERIZATION AND APPLICATION AS CATALYST FOR OLEFIN POLYMERIZATION

New titanium(IV) dichloride complexes containing 2-anilinotropone ligands have been synthesized and characterized. Bis(ligand) titanium dichloride complexes 1 and 2 were synthesized from reaction of TiCl4(THF)(2) with 2 equivalents of the corresponding sodium salts of 2-(2,6-diisopropylanilino) tropone (L1) and 2-(2,3,4,5,6-pentafluoroanilino)tropone (L2), respectively. The mixed cyclopentadienyl-anilinotropone compound 3 was synthesized by reaction of the lithium salt of L2 with CpTiCl3. The Cp-mixed mu-O bimetallic complex 4 was also isolated as a by-product owing to the adventitious presence of moisture. The molecular structures of 1 - 4 have been determined by single-crystal X-ray diffraction studies. Complexes 1 and 2 are isostructural and exhibit a C-2-symmetric octahedral geometry, with a trans (N, N), cis (O, O) arrangement in complex 1, but with a trans (O, O), cis (N, N) arrangement in complex 2. The Cp-mixed complex 3 has a distorted square-pyramidal structure with the Cp ligand in the apical position. Bimetallic complex 4 shows a similar coordination geometry for the five-coordinate titanium atom and a pseudo-tetrahedral coordination for the second metallic centre. All new complexes, when activated with methylaluminoxane, are active in the polymerization of ethylene and propene.