Shigekazu Matsui

A new titanium complex having two phenoxy-imine chelate ligands for ethylene polymerization

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 (M 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 (M 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.

Polymerization of 1-hexene with bis[N-(3-tert-butylsalicylidene)phenylaminato]titanium(IV) dichloride using iBu3Al/Ph3CB(C6F5)4 as a cocatalyst

1-Hexene polymerization was investigated with bis:N-(3-tert-buty salicylidene)phenylamina-to]titanium(IV) dichloride (1) using Bu 3 Al/Ph 3 CB(C 6 F 5 ) as a cocatalyst. This catalyst system produced poly(1-hexene) having a high molecular weight (M a = 445000-884000. 0-60°C). 13 C NMR spectroscopy revealed that the high molecular weight poly(1-hexene) possesses an atactic structure with about 50 mol-% of regioregular units.

Living ethylene/norbornene copolymerisation catalyzed by titanium complexes having two pyrrolide-imine chelate ligands.

Ethylene/norbornene copolymerisation behaviour of titanium complexes with two pyrrolide-imine chelate ligands is described.

132 PI catalysts: New titanium complexes having two pyrrolide-imine chelate ligands for olefin polymerization

Publisher Summary This chapter introduces new titanium complexes bearing two pyrrolide–imine chelate ligands, named PI Catalysts. New bis(pyrrolyl-2-aldiminato) titanium complexes, named PI Catalysts, were prepared from the lithium salt of the corresponding ligands and TiCl 4 , and their molecular structures were established by X-ray analyses. Prototype PI Catalyst adopts a distorted octahedral geometry around the Ti center, thus, the two pyrrole nitrogen atoms are situated in trans position, while the two imine nitrogen and the two chlorine atoms are oriented cis to each other at the central titanium. The results of DFT calculations on a methyl cationic complex, an initial active species formed by methylalumoxane (MAO) for olefin polymerization, indicate that the cationic complex has cis -located active sites. These results together with X-ray analysis suggest that a complex has a high potential for olefin polymerization. PI Catalysts displayed high ethylene polymerization activities using MAO as a cocatalyst. The activity increased dramatically by introducing a bulky X substituent. One of the complexes exhibited a very high activity with a very high molecular weight value.

133 II catalysts: New titanium complexes having two indolide-imine chelate ligands for ethylene polymerization

Publisher Summary This chapter introduces a series of transition metal complexes possessing non-symmetric bidentate ligand(s) which show high catalytic performance for olefin polymerization including living olefin polymerization. The chapter introduces new titanium complexes bearing two indolide–imine chelate ligands, named II Catalysts. Four II Catalysts were synthesized and investigated for their potential as ethylene polymerization catalysts using methylaluminoxane (MAO) as a cocatalyst. Among them, three II Catalysts showed very high activities at room-temperature and produced polyethylenes having extremely narrow molecular weight distributions. The transmission electron microscopy (TEM) micrograph of the block copolymer shows well-defined morphology of micro phase separation, in which white domains corresponding to the polyethylenes (PEs) segment form a fine nanostructue. While those of the blend polymer display the grown lamellar crystals of PE and the stained poly(ethylene-co-propylene). Therefore, the well-defined block copolymer prepared via living polymerization is expected to have a potential as modifier, compatibilizer, or new elastomer.

Efficient ethylene polymerisation catalysis by a cationic benzyl hafnium complex containing pyrrolide-imine ligands

A dibenzyl hafnium(IV) complex containing pyrrolide-imine chelate ligands was synthesized and investigated as an ethylene polymerisation catalyst.