A New Titanium Complex Having Two Phenoxy-Imine Chelate Ligands for Ethylene Polymerization

• Published in: Macromolecular chemistry and physics Vol. 203; no. 1; pp. 59 - 65
• Main Authors: Saito, Junji, Mitani, Makoto, Matsui, Shigekazu, Tohi, Yasushi, Makio, Haruyuki, Nakano, Takashi, Tanaka, Hidetsugu, Kashiwa, Norio, Fujita, Terunori
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 01.01.2002; WILEY‐VCH Verlag GmbH; Wiley
• Subjects: Applied sciences; catalysts; Exact sciences and technology; metallocene catalysts; molecular weight distribution; Organic polymers; Physicochemistry of polymers; polyethylene; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; transition metal chemistry; Polyethylene; Titanium complex; Aryloxy complex; Complex catalyst polymerization; Complex catalyst; Experimental study; Lattice parameters; Solution polymerization; Schiff base; Olefin polymer; Chloro complex; Aluminium Organic compounds; Chemical synthesis; Catalyst activity; Crystalline structure
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/1521-3935(20020101)203:1<59::AID-MACP59>3.0.CO;2-6

A new titanium complex having two phenoxy‐imine chelate ligands, bis[N‐(3‐tert‐butylsalicylidene)anilinato]titanium(IV)dichloride 1, was synthesized and its structure determined by X‐ray analysis. Density functional theory (DFT) calculations and X‐ray analysis suggest that complex 1, when activated, possesses two available cis‐located sites needed for ethylene polymerization. Complex 1/methylaluminoxane (MAO) in toluene or heptane solvent displayed very high ethylene polymerization activities (2 280–4 150 (kg PE)·(mol cat)–1·h–1) with high molecular weight values (M̄v = 288 000–881 000) at 25–75°C under atmospheric pressure. The activity values displayed by complex 1/MAO are some of the highest values exhibited by any titanium complex with no cyclopentadienyl (Cp) ligand(s). Alternatively, complex 1/iBu3Al/Ph3CB(C6F5)4 in toluene solvent displayed high ethylene polymerization activities (190–670 (kg PE)· (mol cat)–1·h–1) with exceptionally high molecular weight values (M̄v = 3 920 000–5 860 000) at 25–75°C under atmospheric pressure. The molecular weight values displayed by complex 1/iBu3Al/Ph3CB(C6F5)4 are some of the largest values displayed by homogeneous olefin polymerization catalysts including the group 4 metallocenes. The high potential of complex 1 for ethylene polymerization has therefore been demonstrated.