Abstract Vanadium complexes with tetradentate salen‐type ligands were first time explored in ethylene polymerizations. The effects of the vanadium complex structure, alkyl aluminum cocatalysts type (EtAlCl 2 , Et AlCl, 3 Al, and MAO), polymerization conditions (Al/V molar ratio, temperature) on polyethylene yield explored. It was found that EtAlCl conjunction investigated produced most efficient catalytic systems. shown, moreover, structural changes salen ligand (type bridge which bond donor...

Abstract In the field of polymers and organometallic chemistry, a significant gap is apparent in area research on well‐defined metal complexes targeted for using catalysis leading to olefinic oligomers polymers. Here, we report use these processes dipicolinate oxovanadium(IV) complexes, without with auxiliary ligands, i. e. 1,10‐phenanthroline 2,2’‐bipyridine. The investigated turned out be versatile precatalysts. After reaction appropriate activator, they exhibited 11 times higher catalytic...

Abstract This article compares catalytic performance of ethylene polymerization in similar conditions transition metal complexes having two ligands [O,N] (phenoxy‐imine) and one tetradentate ligand [O,N,N,O] (salphen or salen). It is shown that the activity both complex types as well product properties depend same way on type central cocatalyst used. Although has some effect catalyst activity, yet it does not control obtained products. The vanadium zirconium complexes, irrespective used,...

Oxovanadium(IV) complexes with [ONNO]-type tetradentate Schiff base ligands: salen, acacen, aceten, acetph (H2salen = N,N′-ethylenebis(salicylideneimine), H2aceten N,N′-ethylenebis(2-hydroxyacetophenoneimine), H2acacen N,N′-ethylenebis(acetylacetonimine), H2acetph N,N′-phenylene-1,2-bis(2-hydroxyacetophenoneimine)), were the first time investigated in ethylene polymerization and ethylene/1-octene copolymerization processes. In general, all these are moderately active precatalyst for upon...

Abstract A supported magnesium‐vanadium‐aluminium catalyst was prepared by depositing –with the use of a milling technique–VOCl 3 on MgCl 2 (THF) support and subsequent activation with diethylaluminium chloride. Catalytic activity obtained system for ethylene polymerization evaluated as function Mg/V Al/V ratios well ageing time temperature. High concentrations THF in catalytic considerable excess an organoaluminium co‐catalyst were found to have no deactivating action vanadium active sites....

The chain end structures of polyethylenes produced by salen complexes titanium, zirconium, and vanadium, activated MAO or common alkylaluminium compounds were investigated 1H NMR FTIR spectroscopy. polymerization process with the use vanadium was found to produce polymers only vinyl groups in practice. In processes catalyzed titanium zirconium Et2AlCl, not β-hydrogen elimination and/or transfer monomer occurs but also termination reaction takes place which an organoaluminium cocatalyst is...

Ethylene/1-olefin copolymerization using vanadium and titanium complexes bearing tetradentate [O,N,N,O]-type ligand EtAlCl2 or MAO as a cocatalyst is carried out. In the presence of complex activated with observed (a) negative "comonomer effect", (b) high comonomer incorporation narrow chemical composition distribution (CCD), (c) unexpected copolymer microstructure, (d) increased molecular weight copolymers when compared homopolymer. contrast, catalyst gives lower 1-olefin content broad CCD....

A series of novel titanium(IV) complexes bearing tetradentate [ONNO] salan type ligands: [Ti{2,2′-(OC6H3-5-t-Bu)2-NHRNH}Cl2] (Lig1TiCl2: R = C2H4; Lig2TiCl2: C4H8; Lig3TiCl2: C6H12) and [Ti{2,2′-(OC6H2-3,5-di-t-Bu)2-NHC6H12NH}Cl2] (Lig4TiCl2) were synthesized used in the (co)polymerization olefins. Vanadium zirconium complexes: [M{2,2′-(OC6H3-3,5-di-t-Bu)2-NHC6H12NH}Cl2] (Lig4VCl2: M V; Lig4ZrCl2: Zr) also for comparative investigations. All turned out active 1-octene polymerization after...

New potentially tridentate Schiff base ligands, 2-[({4-[(3-N,N-dimethylamino)propyl] phenyl}imino)methyl]-4,6-di-tert-butylphenol (L1H) and 2-[{2-(N-phenyl-N-methylaminomethyl)-phenylimino}-methyl]-4,6-di-tert-butylophenol (L2H) were prepared after deprotonation they reacted with VOCl3 or MCl4 (where M = Zr Ti) to produce corresponding complexes (L1-V, L2-V, L1-Zr, L2-Ti) good yields. All new compounds characterized by the 1H 13C NMR as well FTIR spectroscopic methods. Upon activation...

Abstract The study of ethylene/1‐hexene copolymerization with the zirconocene catalyst, bis(cyclopentadienyl)zirconium dichloride (Cp 2 ZrCl )/methylaluminoxane (MAO), anchored on a MgCl (THF) support was carried out. influence 1‐hexene concentration in feed catalyst productivity and comonomer reactivity as well other properties investigated. Additionally, effect modification by organoaluminum compounds [(MAO, trimethlaluminum (AlMe 3 ), or diethylaluminum chloride (Et AlCl)] behavior /Cp...

Abstract Ethylenebis(5‐chlorosalicylideneiminato)vanadium dichloride supported on MgCl 2 (THF) or the same carrier modified by Et n AlCl 3− , where = 1–3, was used in ethylene polymerization presence of MAO a common alkylaluminium compounds as cocatalyst. The support type alter vanadium loading and also change characteristic catalytic active sites. is best activator for catalyst which has been immobilized nonmodified support, whereas systems contain an organoaluminium compound reveal highest...

Polymerizations of 1-octene were carried out in the presence vanadium and titanium complexes bearing salen-type or phenoxyimine ligands activated with various co-catalysts. Vanadium turned active only conjunction MAO, whereas ones combination Al(i-Bu)3/Ph3CB(C6F5)4. The activity all catalysts was moderate low it dependent on ligand type: bis(phenoxyimine) more than salen ones. Both catalytic systems produced poly(1-octene)s possessing atactic structures [mmmm] sequences range from 12 to 56 %...

ABSTRACT Copolymerization of ethylene with iso ‐butyl substituted monoalkenyl(siloxy)‐ or monoalkenylsilsesquioxane (POSS) comonomers over bis(phenoxy‐imine) and salen‐type titanium zirconium catalysts was studied. It found that the polyreaction performance significantly depended by kind catalyst structure concentration POSS in feed. The comonomer efficiently incorporated into polymer chain at up to 0.2 mol %. differences copolymer compositions as functions were observed, including varied...

Slurry polymerizations of ethylene over vanadium catalysts (based on VCl4 and VOCl3) their MgCl2(THF)2-supported equivalents were studied. Unsupported found to be unstable while the active sites deposited MgCl2(THF)2 complex are stable. A sharply outlined correlation was between concentration vanadium(III) catalyst productivity. The high activity stability when supported magnesium is attributed increase resistance reduction inactive vanadium(II) by an organoaluminium co-catalyst.

The series of salen-type complexes differing in the metal center (M=Ti, Zr, V) and coordination spheres (different substituent at salen ligands) after activation with methylalumoxane (MAO) or Et2AlCl were studied as catalytic systems ethylene polymerization. vanadium titanium found to be more active combination alkylaluminum compound (Et2AlCl) then MAO, while zirconium complex was only MAO. activity activated by decreases order V>Ti>>Zr?0, when MAO is used cocatalyst changes order: Ti>Zr>V....

Abstract Immobilization of 1,2‐cyclohexylenebis(5‐chlorosalicylideneiminato)vanadium dichloride on the magnesium support obtained in reaction MgCl 2 ·3.4EtOH with Et AlCl gives a highly active precursor for ethylene homopolymerization and its copolymerization 1‐octene. This catalyst exhibits highest activity conjunction MAO, but it is also AlMe 3 as cocatalyst. On other hand, when combined chlorinated alkylaluminum compounds, EtAlCl , traces polyethylene. Moreover, catalytic strongly...