title: New anilinotropone-based titanium complexes: synthesis, characterization and application as catalysts for olefin polymerization.
abstract: 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 with CpTiCl3. The Cp-mixed micro-O bimetallic complex 4 was also isolated as a by-product owing to the adventitious presence of moisture. The molecular structures 1-4 of have been determined by single-crystal X-ray diffraction studies. Complexes 1 and 2 are isostructural and exhibit a C2-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.
authors.affiliation: Dipartimento di Chimica, Università di Salerno, via S. Allende, I-84081, Baronissi, Salerno, Italy. mmazzeo@unisa.it
authors.forename: Mina
authors.initials: M
authors.lastname: Mazzeo
authors.forename: Marina
authors.initials: M
authors.lastname: Lamberti
authors.forename: Angela
authors.initials: A
authors.lastname: Tuzi
authors.forename: Roberto
authors.initials: R
authors.lastname: Centore
authors.forename: Claudio
authors.initials: C
authors.lastname: Pellecchia
mesh_terms: D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry*; D014326:Tropanes / Q000737:chemistry*
chemical_list: D000475:Alkenes; D000814:Aniline Compounds; D008024:Ligands; D009942:Organometallic Compounds; D014326:Tropanes; D014025:Titanium