Chromium and nickel catalysts for oligomerization reactions and process for obtaining alpha-olefins using said catalysts

摘要

The present invention refers to the synthesis of precatalysts and the use of such precatalysts in ethylene oligomerization reactions for the selective production of alpha-olefins. More specifically, it refers to the preparation and use of coordination compounds containing polydentate ligands comprising Group 6 and 10 transition metal compounds, in particular chromium (III) and nickel (II). Such catalytic precursors present high catalytic activity and selectivity for the production of alpha-olefins.

主权项

1. A catalyst of the general formula LMXn, where “M” is a metal, “X” is an anion, and “n” is the number of anions “X” present in each molecule, varying from 1 to 3, and “L” is a polydentate nitrogen ligand of formula: wherein “E” is a heterocycle pyridine ring, an imidazole ring or an element selected from among oxygen or sulfur, R1, R2 and R3 are each, independently of one another, located respectively at positions 3, 4 and 5 of the pyrazolyl radical and selected from among hydrogen atoms, hydrocarbyl radicals with a number of carbon atoms equal to or greater than 1, wherein when E is a heterocycle pyridine ring or an imidazole ring, R4 is an atom of hydrogen or a radical selected from among aliphatic C4-C20 hydrocarbyls, an aliphatic C1-C20 hydrocarbyl containing at least one C6-C14 aromatic radical, an non substituted C6-C20 aromatic radical and a C6-C20 aromatic hydrocarbyl with at least one C1-C10 alkyl substituent, wherein when E is oxygen or sulfur, R4 is absent, and wherein when E is a heterocycle pyridine ring, R4 is not hydrogen.