Seven new and one previously described pyrazolylimine complex NiBr2 with aryl substituents exhibiting different electronic effects on the imine carbon atom were synthesized and characterized. It was shown that the obtained compounds are effective catalysts for ethylene polymerization in the presence of diethylaluminum chloride (DEAC).The influence of the electronic properties of the R substituents on the catalytic performance of the complexes was systematically investigated. A clear correlation between ligand electron-donating or -withdrawing character and both polymer molecular weight and catalytic activity was observed, providing insight into the electronic factors governing the efficiency of these nickel-based systems.

Ionic heterometallic complexes containing potassium and ammonium cations in the cavity of dibenzo-24-crown8 and anion [TiCl6]- have been synthesized. The structure of these compounds was determined by X-ray diffraction analysis. In the presence of the Al/Mg activators - Et2AlCl/Bu2Mg or Et2AlCl/Me3Al/(4-tBuC6H4O)2Mg the complexes catalyze the polymerization of ethylene with activity up to 5320 kg PE/mol Ti h atm) with the formation of ultrahigh molecular weight polyethylene (UHMWPE) with molecular weights up to 4.5 center dot 106 Da. Ionic heterometallic complexes are superior in activity to neutral extra-cavity molecular complexes DB24C8 center dot TiCl4.

In the present work, several dibromonickel (II) complexes ligated by tetradentate NNNX and tridentate NNN pyrazole-containing compounds were synthesized and compared in detail as precatalysts for ethylene oligomerization. All nickel complexes, after activation by DEAC or EASC (diethylaluminium chloride or ethyl-aluminium sesquichloride), showed moderate activity (110 to 1100 kgPE/(molNih)), producing predominantly short-chain olefins (C4 and C6). The introduction of additional donor atoms (X) to the tridentate NNN 3,5-dimethylpyrazole-containing ligand leads to an increase in catalytic activity in the sequence of the nickel (II) complexes activated by 300 eq. DEAC with NNN GG NNNN G NNNO GG NNNS (55 GG 225 G 280 GG 505 kgPE/ (molNih)) ligands. For the dibromonickel (II) complex with an additional nitrogen donor (X = N), the optimal Al/ Ni ratio was established as 75 eq. (1010 and 250 kgPE/(molNi h), activated by DEAC and EASC, respectively). The complexes bearing tetradentate NNNN ligands with unsubstituted and 4-bromo-3,5-dimethylpyrazole rings were also tested under these conditions. The structure of the latter complex was established by X-ray diffraction; it is shown that all four nitrogen atoms coordinate with the metal and form three five-membered chelate cycles.

A series of Ni (II) aqua complexes with tetrapodal ligands containing pyrazole fragments has been synthesized. Single-crystal X-ray analysis of complex 1a reveals that the nickel center adopts a distorted octahedral coordination geometry. All the obtained complexes exhibited high catalytic activity in the ethylene oligomerization reaction (up to 198 & sdot;103 h-1) after activation with organoaluminum compounds, significantly surpassing their anhydrous analogs (by up to 5.5 times). The oligomeric product distribution is mainly composed of butenes (25-97 %), hexenes (3-58 %), and octenes (0-17 %), without pronounced selectivity for alpha-isomers.

Titanium(4+) complexes with tetraaryldioxolane-dimethanol (TADDOL) ligands were obtained. Their catalytic activity in the ethylene polymerization was evaluated. It was shown that, in the presence of Al activators, the resulting compounds catalyze the ethylene polymerization highly efficiently (up to 3400 kg PE·mol(Ti)–1·h–1·atm–1), resulting in the formation of ultra-high-molecular-weight polyethylene (UHMWPE) with a molecular weight of up to 4.50 106 Da.

It was shown by EPR spectroscopy that Ti(IV) was gradually reduced to Ti(III) when a titanium(IV) dichloride complex with a saligenin ligand was used as a model pre-catalyst in the presence of (EtnAlCl3–n + Bu2Mg) as an activator. Pre-activation of this complex (by stirring in an inert atmosphere with a half-load of the Al/Mg activator before being introduced into the reactor) significantly (about twofold) enhanced its catalytic activity, up to 4100 kgPE molTi–1 h–1 atm–1. All the synthesized polyethylene samples were linear ultrahigh-molecular-weight polymers (UHMWPEs) with Mv = 1.0–3.5×106 g/mol. This pre-activation technique was further employed to test a series of Al/Mg activators that differed in the nature of their organometallic compounds and in their Al/Mg molar ratio. The test data suggest that the catalytic system under study had active sites with titanium being present mainly in the oxidation state of +3. Most samples of UHMWPE produced with the pre-activated complex proved suitable for solvent-free processing into high-strength oriented films.

A new fluorine-containing OOO2−-type chelating ligand and the titanium(iv) dichloride and bis-isopropoxide complexes with this ligand were synthesized. The structure of the titanium(iv) bis-isopropoxide complex was determined by single-crystal X-ray diffraction analysis. In the presence of Al/Mg activators (Et2AlCl-Bu2Mg or Et3Al2Cl3-Bu2Mg), both complexes catalyze the ethylene polymerization giving ultra-high-molecular-weight polyethylene with a molecular weight of up to 5.8 • 106 Da. Due to a low degree of polymer entanglement, these polymers can be processed by a solvent-free method to prepare high-strength high-modulus films with a Young’s modulus up to 117 GPa and a tensile strength up to 2.18 GPa.

The polymerization of ethylene and propylene and the copolymerization of ethylene with 1-octene with novel type of post-metallocene catalysts containing ionic complexes [2L·M@dibenzo-18-crown-6]+ [TiCl5·L]– (L = CH3CN, M = Li, K) are studied. The binary activator Al(C2H5)2Cl/Mg(C4H9)2 at [Al] : [Mg] 3 is used as a cocatalyst. A linear crystalline polyethylene, an almost fully amorphous, atactic polypropylene, and statistical ethylene-1-octene copolymers containing from 2 to 9 mol

New ionic complexes with various metals (Mg2+, titanium in various oxidation states, and iron triad metals) in the 15-crown-5 cavity as a cation and a titaniumcontaining anion have been synthesized. The structure of some synthesized complexes was determined by X-ray diffraction analysis. These compounds, in the presence of the Al/Mg activator {Et2AlCl + Bu2Mg}, catalyze the polymerization of ethylene with the formation of ultrahigh molecular weight polyethylene (UHMWPE) with molecular weights up to 2.56 & sdot;106 Da. Only complexes with a titanium-containing anion showed catalytic activity; its maximum value -4651 kg of PE/mol & sdot;h & sdot;atm was exhibited by the complex [15C5 superset of FeoCl & sdot;2CH3CN]2+[Ti2Cl10]2-. The resulting ultra -high molecular weight polyethylene (Mv to 2.56 center dot 106 Da) can be processed by a solventless method into high-strength (up to 2.45 GPa) and high-modulus (up to 144 GPa) oriented tapes. Most polyethylene samples have a linear structure, with the exception of polymers obtained on Ni/Ti complexes, which have 2-3 branches per 1000 carbon atoms.

A novel catalyst system containing a complex of Ti4+ with a (O,N,O)-tridentate phenoxyimine ligand and a binary Al(C2H5)2Cl/Mg(C4H9)2 activator at a molar [Al]/[Mg] ratio of 3 affords the synthesis of ethylene polymers with molecular weight in excess of 1 × 106. Ethylene homopolymer produced at 35°C has Mw 2.6 × 106 and ethylene copolymers with small amounts (below 1 mol

New titanium(+4) and vanadium(+5) 8-oxyquinolinate complexes were synthesized. Their structures were determined by X-ray diffraction. The synthesized compounds catalyze the polymerization of ethylene in the presence of Al/Mg activators, Et2AlCl/Bu2Mg and Et3Al2Cl3/Bu2Mg (up to 3400 kg of PE (mol of [M] h atm)−1), to form ultrahigh-molecular-weight polyethylene with a molecular weight up to 5.3•106 Da. The synthesized compounds are shown to be efficient precatalysts for the synthesis of ethylene-octene copolymers. A high insertion of 1-octene into the copolymer composition, up to 9.5

Изучены реакции полимеризации этилена, пропилена и сополимеризации этилена с октеном-1 на новом типе пост-металлоценовых катализаторов, осно- ванных на анионе TiCl5 – и комплексах Li+ и K+ с краун-эфиром. Оба комплекса в кристаллическом состоянии сольватированы ацетонитрилом.

Based on previously accumulated experimental material on the use of {nEt2AlCl + Bu2Mg} mixtures for the activation of Ti postmetallocene precatalysts for ethylene polymerization, an attempt is made to find the reason for the universal activating ability of such cocatalysts by analyzing the chemical processes occurring during the interaction of alkylaluminum chlorides and dibutylmagnesium. 1H and 27Al NMR spectroscopy data indicate that in nonsolvating media the formation of ionic products (with which earlier the unique activating ability of Al/Mg activators was associated) does not occur. The "true" Al/Mg cocatalysts are uncharged adducts of MgCl2 with alkylaluminum chlorides and/or trialkylaluminum. It was shown that all used Al/Mg cocatalyst compositions are capable of activating a model titanium dichloride complex with a saligenin ligand with varying efficiencies. The product of the ethylene polymerization is an ultrahigh molecular weight polymer (M v from 1.1 to 5.1 x 106 Da); the latter is evidenced by the possibility of solid-phase processing of nascent polymer powders into high-strength, high-modulus tapes (breaking strength up to 2.4 GPa and elastic modulus up to 112 GPa).

A series of novel complexes of titanium(IV) with OSSO-type ligands were synthesized. In the presence of Al/Mg activators such as Et2AlCl+Bu2Mg and Et3Al2Cl3+Bu2Mg, all the synthezed compounds catalyzed the polymerization of ethylene (with activity up to 2554 kgPE molM–1 h–1 atm–1). The otained ultrahigh-molecular-weight polyethylene (UHMWPE) samples had a molecular weight up to 7.6×106 Da and exhibited high melting points (up to 143°C) and high crystallinity (up to 84

This work shows for the first time the influence of the method of introducing Mg compounds into a post-metallocene-type catalytic system on its catalytical performance and the properties of the resulting polymer, and it is concluded that the real catalytic center is heterometallic Ti/Mg complexes. Compares three different approaches to introducing Mg compounds into catalytic systems containing a titanium(IV) dichloride complex with an (O^O)2- type ligand and an organoaluminium compound - the use of Al/Mg co-catalysts, the immobilization of a Ti complex on the surface of anhydrous MgCl2 and in situ preparation of heterometallic Ti/Mg complexes. All three approaches lead to the production of ultra-high molecular weight polyethylene, but systems with externally introduced magnesium chloride showed the lowest productivity. UHMWPE samples synthesized on Ti/Mg precatalysts and conventional OAC are suitable for solvent-free solid-phase processing into high-strength, high-modulus film threads.

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts (Ni1: Ar = Ph; Ni2: Ar = 2-(C6H5)C6H4; Ni3: Ar = 2-[2′,6′-(MeO)2-C6H3]C6H4) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes Ni2 and Ni3 contributed to high catalytic activities (up to 7.24×106 and 9.04×106 g·molNi−1·h−1, respectively), and produced high-molecular-weight polyethylene (Mw up to 545.7 kDa). Complex Ni3 exhibited high activities for ethylene polymerization at the level of 106 g·molNi−1·h−1 across a wide range from 30 °C to 120 °C, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights (Mw up to 80.5 kDa) and high polar monomer incorporation (up to 8.2 mol

A series of Ti(IV) dichloride and dialkoxide complexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been synthesized. The molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction studies. The complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands (Cl or i PrO) are situated in cis position. Effect of activators (MMAO-12 and combinations Et n AlCl 3− n + Bu 2 Mg) and outgoing ligand (Cl or i PrO) nature on the catalytic activity and properties of the resulting polymers was studied. The Ti complexes, despite the nature of the outgoing ligands (Cl or i PrO) in the presence of Al/Mg activators, was found to display a high ethylene polymerization activity in the range 1600–3830 kg polymer ·mol Ti −1 ·h −1 ·atm −1 with a viscosity average molecular weight ( M v ) value in the range 1.1×10 6 −7.1×10 6 Dalton (Da). The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented films. The rheological characteristics of a polymer melt have been studied. The absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts, however, the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented films. Upon activation with methylalumoxane, the activity of the complexes decreased very significantly; however, a polymer with a molecular weight of about 12 million Da was obtained. In the process of ethylene/octene-1 copolymerization, fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

The OSSO-type diol ligand and the TiIV dichloride and bis-isopropoxide complexes with this ligand were synthesized. The structure of the latter complex was determined by single-crystal X-ray diffraction analysis. The catalytic activity of the systems based on the complexes (OSSO)TiCl2 and (OSSO)Ti(OPri)2, which were activated with mixtures of alkylaluminum chlorides (Et2AlCl, Et3Al2Cl3) and dibutylmagnesium, was studied in the polymerization of ethylene and its copolymerization with propylene. It was found that the homopolymerization affords ultra-high-molecular-weight polyethylene (UHMWPE) with a molecular weight up to 10.6·106, and the copolymerization gives copolymers containing up to 43 mol.

Nickel(II) complexes with pyrazole-based ligands are widely employed in catalysis of ethylene oligomerization and subsequent Friedel-Crafts alkylation of toluene. We have prepared ten new nickel(II) dibromide complexes with various substituted bis(azolyl)methanes. They have been characterized using 1H NMR, IR, MALDI-TOF and elemental analysis. The structures of three complexes have been unambiguously established using X-ray diffraction. It was found that these complexes in the presence of Et2AlCl or Et3Al2Cl3 are active both in ethylene oligomerization and Friedel-Crafts alkylation processes (activity up to 3720 kgoligomer·mol[Ni]−1·h−1). The use of Et3Al2Cl3 results in the higher share of alkylated products (up to 60%). Moreover, catalytic systems activated with Et3Al2Cl3 produced small amounts of odd carbon number olefins (up to 0.8%). The Friedel-Crafts alkylation was used as a trap for previously undetected short-chain odd carbon number olefins (C3 and C5).