The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The invention pertains to a composition that comprises at least one chromium precursor, at least one heteroatomic ligand, and, optionally, at least one activator. The invention also pertains to the method for preparation of the composition in accordance with the invention and the use of said composition in a method for oligomerization of olefins.

Organometallic complexes are described which are useful as pre-polymerization catalysts which may form part of olefin polymerization catalyst systems. The catalyst systems find use in the polymerization of ethylene, optionally with one or more C.sub.3-12 alpha-olefin comonomers. The organometallic complexes are broadly represented by formula I: ##STR00001##
wherein L is a bridging group containing a contiguous chain of atoms connecting P with Cy, wherein the contiguous chain contains 2 or 3 atoms and wherein Cy is a cyclopentadienyl-type ligand. The olefin polymerization catalyst system is effective at polymerizing ethylene with alpha-olefins in a solution phase polymerization process at high temperatures and produces ethylene copolymers with high molecular weight and high degrees of alpha-olefin incorporation. Pre-metallation compounds, metallation processes and synthetic methods to make the organometallic complexes as well as polymerization processes are also described.

The present invention relates to a method of preparing -olefins by oligomerization of C.sub.2-C.sub.4 olefins. The method is carried out by oligomerization of C.sub.2-C.sub.4 olefins in the presence of a catalyst system comprising a transition metal source, an activator, which is an alkylaluminoxane, and a compound of formula (I), Ar.sup.1Ar.sup.2PN(R)PAr.sup.3Ar.sup.4 [formula I], wherein Ar.sup.1-4 are the same or different and are selected from substituted or unsubstituted C.sub.6-C.sub.10 aryl, R is selected from linear or branched C.sub.1-C.sub.4 alkyl, substituted or unsubstituted C.sub.6-C.sub.10 aryl, and substituted or unsubstituted C.sub.3-C.sub.10 cycloalkyl, wherein the oligomerization is carried out in a solvent, which is a bicyclic compound or a mixture of bicyclic compounds, preferably decalin. The claimed method provides a significant increase in the activity of the catalyst during the oligomerization process and, as a consequence, a reduction in the catalyst unit consumption, as well a reduction in the formation of polymer by-product.

The present invention relates to a ligand compound, a catalyst system for olefin oligomerization, and a method for oligomerizing olefins using the same. The ligand compound according to the present invention has a structure in which a substituent is substituted in the trans form, and thereby when used for olefin oligomerization, the activity of the catalyst used and the selectivity of 1-hexene and 1-octene can be increased.

A catalyst system is disclosed. The catalyst system may include a pre-catalyst and a co-catalyst. The pre-catalyst includes one or more chromium compounds coordinated with a ligand. The co-catalyst includes one or more organoaluminum compounds, wherein: the ligand has a structure according to formula (I): ##STR00001## In formula (I), R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently chosen from (C.sub.6-C.sub.60) aryl, optionally substituted with one or more R.sup.S, wherein R.sup.S is a (C.sub.1-C.sub.50) hydrocarbyl or a (C.sub.1-C.sub.50) heterohydrocarbyl. In formula (I), R.sup.5 is a (C.sub.9-C.sub.60) aryl or a (C.sub.4-C.sub.60) heteroaryl, optionally substituted with one or more R.sup.S, wherein R.sup.S is a (C.sub.1-C.sub.50) hydrocarbyl or a (C.sub.1-C.sub.50) heterohydrocarbyl, provided that R.sup.5 is not naphthyl or triptycenyl.

The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The present disclosure relates to a method for oligomerization of olefins. The method for oligomerization of olefins according to the present disclosure not only provides excellent catalytic activity and stable process operation, but also exhibits high selectivity to 1-hexene or 1-octene by using a catalyst system including an activity modifier.

N.sup.2-phosphinyl amidine compounds, N.sup.2-phosphinyl amidinates, N.sup.2-phosphinyl amidine metal salt complexes, N.sup.2-phosphinyl amidinate metal salt complexes are described. Methods for making N.sup.2-phosphinyl amidine compounds, N.sup.2-phosphinyl amidinates, N.sup.2-phosphinyl amidine metal salt complexes, and N.sup.2-phosphinyl amidinate metal salt complexes are also disclosed. Catalyst systems utilizing the N.sup.2-phosphinyl amidine metal salt complexes and N.sup.2-phosphinyl amidinate metal salt complexes are also disclosed along with the use of the N.sup.2-phosphinyl amidine compounds, N.sup.2-phosphinyl amidinates, N.sup.2-phosphinyl amidine metal salt complexes, and N.sup.2-phosphinyl amidinate metal salt complexes for the oligomerization and/or polymerization of olefins.

The present invention relates to a method for preparing an oligomerization catalyst system and the method comprises preparing a catalyst composition by mixing a PNP-based ligand compound and a transition metal compound, and mixing and activating a co-catalyst and the catalyst composition at a temperature from 40 to 80 C. The oligomerization catalyst system prepared by the method may maintain the activity thereof during an oligomerization reaction at a high temperature, and the reaction temperature of oligomerization may be easily controlled. Various merits in processing may be obtained.