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A New Titanium Complex Having Two Phenoxy‐Imine Chelate Ligands for Ethylene Polymerization
Author(s) -
Saito Junji,
Mitani Makoto,
Matsui Shigekazu,
Tohi Yasushi,
Makio Haruyuki,
Nakano Takashi,
Tanaka Hidetsugu,
Kashiwa Norio,
Fujita Terunori
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020101)203:1<59::aid-macp59>3.0.co;2-6
Subject(s) - methylaluminoxane , polymerization , ethylene , polymer chemistry , chemistry , cyclopentadienyl complex , toluene , molar mass distribution , titanium , metallocene , coordination polymerization , solution polymerization , polymer , catalysis , organic chemistry
Abstract 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 ( M̄ v = 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 / i Bu 3 Al/Ph 3 CB(C 6 F 5 ) 4 in toluene solvent displayed high ethylene polymerization activities (190–670 (kg PE)· (mol cat) –1 ·h –1 ) with exceptionally high molecular weight values ( M̄ v = 3 920 000–5 860 000) at 25–75°C under atmospheric pressure. The molecular weight values displayed by complex 1 / i Bu 3 Al/Ph 3 CB(C 6 F 5 ) 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.