G. P. Belov

Processes for the production of higher linear α-olefins

The results of scientific investigations and industrial developments in the field of the selective and statistical oligomerization of ethylene to obtain higher linear α-olefins are generalized.

Tetramerization of ethylene to octene-1 (a review)

Data on the activity, selectivity, and reaction conditions for the selective oligomerization of ethylene to octene-1 mediated by chromium-containing organic compounds in combination with organoaluminum compounds have been summarized and analyzed. Possible schemes for the mechanism of the formation of octene-1 and byproduct cyclic hydrocarbons (methylenecyclopentane and methylcyclopentane) and higher (>C8) linear olefins have been briefly discussed.

Ethylene oligomerization on the chromium ethylhexanoate-triethylaluminum-2,5-dimethylpyrrol catalytic system in the presence of carbon tetrachloride

The kinetics of the selective ethylene oligomerization reaction on the chromium(III) ethylhexanoate-Al(C2H5)3-2,5-dimethylpyrrol homogeneous catalytic system in the presence of CCl4 has been studied. The reaction rate order in ethylene, the activation energy, and the selectivity of reaction for 1-hexene have been determined.

Ethylene oligomerization over catalyst systems based on chromium(III) and aluminum coordination compounds

The influence of the nature of a cocatalyst, a stabilizing ligand, and an introduced modifier on the behavior of the ethylene oligo- and polymerization reaction in the presence of the Cr(acac)3-AlR3-L-M catalyst system, where AlR3 is triethylaluminum (AlEt3), dichloroethylaluminum (AlEtCl2), or methylalumoxane (MAO); L is pyrrole (PyH) or bis(diphenylphosphino)cyclohexylamine ((Ph2P)2NCy); and M is tetrachloromethane (CCl4), has been studied. The maximal selectivity for hexene-1 has been found to be 86 wt %.

Mechanochemical Synthesis of Chromium Tris(2-ethylhexanoate) and Evaluation of Its Catalytic Activity in the Reaction of Ethylene Trimerization

A method was developed for synthesis of chromium(III) tris(2-ethylhexanoate) by the mechanochemical interaction of chromium(III) chloride with sodium 2-ethylhexanoate without a solvent, followed by heating of the reaction mixture. The influence exerted by the conditions of the mechanical activation and the subsequent thermal treatment on the course of the processes and some properties of activated mixtures was studied. Chromium(III) tris(2-ethylhexanoate) can be isolated from the reaction mixture in a ∼75% yield. Both the activated reaction mixture and the target product obtained exhibit a high catalytic activity and selectivity in the reaction of ethylene trimerization.

Ethylene oligomerization in the presence of catalytic systems based on nickel(II) formazanates

The influence of the temperature, the pressure, the Al/Ni molar ratio, and the position of chlorine-containing substituents in formazan ligands on the reaction kinetics and the product composition in the ethylene oligomerization catalyzed by thea system based on nickel(II) formazanates and ethylaluminium dichloride has been studied. It has been shown that effective metal complex catalyst systems can be prepared via varying the nature and the position of the substituents in the ligands.

Selective dimerization of ethylene to but-1-ene under the conditions of industrial process. I. Influence of temperature and pressure on the rate of the process in a bubbling type reactor

Analysis of mass and heat balance in the reaction node of the process of ethylene dimerization into but-1-ene under the industrial conditions is performed. It is found that ethylene concentration in the reactor liquid phase by a complex way depends on the reactor temperature, pressure and but-1-ene concentration in the liquid phase. Optimal process temperature is 80–90°C, operating pressure in the reactor is 0.6–0.8 MPa. Increase in pressure above 1 MPa practically excludes heat withdraw via but-1-ene evaporation and makes the system of heat withdrawing ineffective.

Selective dimerization, oligomerization, homopolymerization and copolymerization of olefins with complex organometallic catalysts

Review embarrasses the problems of low molecular weight olefins (ethylene and propylene) selective oligomerization to butene-1, hexene-1, octene-1, 4-methylpentene-1; selective polymerization of olefins to obtain polymers with a given molecular mass, molecular mass distribution, branching (for the polyethylene), chain structure [atactic, iso-, syndio-, gemiisotactic, stereoblock type and containing terminal vinyl and vinylidene bonds (for polypropylene)]; “live” homo-and copolymerization of olefins, and alternating copolymerization of olefins in the presence of complex organometallic catalysts.

Ethylene oligomerization over chromium(III) complexes with pyrrole derivatives

The effect of the nature of a chromium(III) coordination compound and various substituted pyrrole ligands on ethylene oligomerization in the presence of a Cr(III) complex–pyrrole ligand (L)/AlEt3 catalyst system (CS), where Cr(III) is Cr(EH)3, Cr(асас)3, or CrCl3(THF)3 and L is pyrrole, 2-phenylpyrrole, 2-formylpyrrole, N-methylpyrrole, or N-vinyl-2-phenylpyrrole, has been studied. It has been shown that the most significant effect on the behavior of the CS is exerted by the nature of the ligand involved in the formation of the CS. The acid–base properties of the employed ligands have been determined by quantum-chemical calculations. The data obtained have revealed that selectivity of the catalyst system depends on the ligand basicity.

New catalytic systems on the basis of chromium compounds for selective synthesis of 1-hexene and 1-octene

Based on the analysis of scientific and patent literature published over the period from June, 2010 to February, 2016, data on catalytic metal complex systems on the basis of chromium with various degrees of oxidation in the reaction of selective tri- and/or tetramerization of ethylene have been systematized and described. Key information about catalytic systems exhibiting high selectivity for higher alpha-olefins (1-hexene and 1-octene) or their mixtures is surveyed.