The disclosure provides a catalyst system and a method for ethylene oligomerization using this. The catalyst system contains: ligand a, containing carbene groups of imidazole ring type; transition metal compound b, that is one of IVBVIII group metal compounds; activator c, that is a compound containing III A group metals; the ligand a contains at least one group as shown in general formula I:

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in which, bridging group A contains a main chain including alkyl, alkenyl, aryl groups or the combination of them and the first heteratom; E is a linear or cyclic group containing the second heteroatom; R is a hydrocarbyl group. The catalyst system is especially used for trimerization and tetramerization of ethylene. The catalyst system has high selectivity for 1-hexene and 1-octene, low selectivity for 1-butene and I-C.sub.10+, and the total percent content of C.sub.6C.sub.8 linear -olefin in the product is more than 90% by mass.

A composition containing a supported hydrogenation catalyst comprising palladium and a support, wherein the supported hydrogenation catalyst is capable of selectively hydrogenating highly unsaturated hydrocarbons to unsaturated hydrocarbons, and a dopant, wherein the dopant comprises at least one component selected from zwitterions, ylides, betaines, or combinations thereof. A method of making a selective hydrogenation catalyst by contacting a support with a palladium-containing compound to form a supported-palladium composition, contacting the supported-palladium composition with a dopant to form a selective hydrogenation catalyst precursor, wherein the dopant comprises at least one component selected from zwitterions, ylides, betaines, or combinations thereof, and reducing the selective hydrogenation catalyst precursor to form the selective hydrogenation catalyst. A selective hydrogenation catalyst produced via the method of making a selective hydrogenation catalyst, and a method of selectively hydrogenating highly unsaturated hydrocarbons to an unsaturated hydrocarbon enriched composition are also provided.

The invention concerns ionic compounds in which the anionic load has been delocalized. A compound disclosed by the invention is comprised of an amide or one of its salts, including an anionic portion combined with at least one cationic portion M.sup.+m in sufficient numbers to ensure overall electronic neutrality; the compound is further comprised of M as a hydroxonium, a nitrosonium NO.sup.+, an ammonium NH.sub.4.sup.+, a metallic cation with the valence m, an organic cation with the valence m, or an organometallic cation with the valence m. The anionic portion matches the formula R.sub.FSO.sub.xN.sup.?Z, where R.sub.F is a perflourinated group, x is 1 or 3, and Z is an electroattractive substituent. The compounds can be used notably for ionic conducting materials, electronic conducting materials, colorants and the catalysis of various chemical reactions.

A composition containing a supported hydrogenation catalyst comprising palladium and a support, wherein the supported hydrogenation catalyst is capable of selectively hydrogenating highly unsaturated hydrocarbons to unsaturated hydrocarbons, and a dopant, wherein the dopant comprises at least one component selected from zwitterions, ylides, betaines, or combinations thereof. A method of making a selective hydrogenation catalyst by contacting a support with a palladium-containing compound to form a supported-palladium composition, contacting the supported-palladium composition with a dopant to form a selective hydrogenation catalyst precursor, wherein the dopant comprises at least one component selected from zwitterions, ylides, betaines, or combinations thereof, and reducing the selective hydrogenation catalyst precursor to form the selective hydrogenation catalyst. A selective hydrogenation catalyst produced via the method of making a selective hydrogenation catalyst, and a method of selectively hydrogenating highly unsaturated hydrocarbons to an unsaturated hydrocarbon enriched composition are also provided.

Process for increasingly producing D-Lactide and meso lactide by depolymerizing by back biting polylactide (PLA) said process which comprises: (i) Depolymerizing polylactide into its corresponding dimeric cyclic esters by heating the polylactide in the presence of a catalyst system comprising a catalyst and a co-catalyst in a reaction zone at temperature and pressure at which the polylactide is molten; (ii) Forming a vapor product stream from the reaction zone; (iii) Removing the vapor product stream and optionally condense it; (iv) Recovering, either together or separately meso-lactide, D-lactide and L-lactide.

Provided are a water-soluble triarylphosphine for a palladium catalyst, which has high selectivity in a telomerization reaction and is easily recovered with efficiency, an ammonium salt thereof, and a method for efficiently producing the same. Specifically, provided are bis(6-methyl-3-sulphophenyl)(2-methylphenyl)phosphine; a bis(6-methyl-3-sulphonatophenyl)(2-methylphenyl)phosphine diammonium salt obtained by reacting the phosphine with a tertiary amine having a total of 3 to 27 carbon atoms in groups bonded to one nitrogen atom; and a method for producing the same.

The invention concerns a catalytic composition comprising: at least one nickel precursor with an oxidation number of (+II), at least one phosphine ligand with formula PR.sup.1R.sup.2R.sup.3 in which the groups R.sup.1, R.sup.2 and R.sup.3, which may be identical or different and which may or may not be bonded together, and at least one Lewis base, said composition having a molar ratio of the phosphine ligand to the nickel precursor of less than or equal to 5 and a molar ratio of the Lewis base and phosphine ligand together to the nickel precursor of greater than or equal to 5.

The present disclosure provides a method for preparing ((2,2-dimethyl-1,3-dioxane-5,5-diyl)bis(methylene))bis(bis(2-methoxyphenyl)phosphine), a ligand for a polyketone polymerization catalyst, under mild conditions with high purity and high yield. Therefore, the preparation method of the present disclosure can be easily applied to mass production.

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.

The present invention relates generally to processes for producing aldehydes wherein an olefinic compound, carbon monoxide, and hydrogen are reacted in the presence of a solubilized rhodium-phosphorous complex. In one embodiment, the process comprises (a) receiving a vaporized aldehyde product stream downstream from a hydroformylation reactor, the vaporized aldehyde product stream comprising aldehydes, phosphorous ligand, and aldehyde condensation by-products; (b) contacting the vaporized aldehyde product stream with a partial condenser so as to condense the phosphorous ligand and the by-products, wherein up to 10 weight percent of the vaporized stream is condensed; (c) removing the condensed phosphorous ligand and the condensed by-products from the liquid condensation stream using a refining column; and (d) further processing the vaporized aldehydes from the separate refining column.