The invention relates to a method of forming an olefin from a first olefin and a second olefin in a metathesis reaction, comprising step (i): (i) reacting the first olefin with the second olefin in the presence of a compound that catalyzes said metathesis reaction such that the molar ratio of said compound to the first or the second olefin is from 1:500 or less, and the conversion of the first or the second olefin to said olefin is at least 50%, characterized in that as compound that catalyzes said metathesis reaction a compound of the following formula is used:

##STR00001## wherein M is Mo or W; R.sup.1 is aryl, heteroaryl, alkyl, or heteroalkyl; optionally substituted; R.sup.2 and R.sup.3 can be the same or different and are hydrogen, alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl; optionally substituted; R.sup.5 is alkyl, alkoxy, heteroalkyl, aryl, heteroaryl, silylalkyl, silyloxy, optionally substituted; and R.sup.4 is a residue R.sup.6X, wherein X=O and R.sup.6 is aryl, optionally substituted; or X=S and R.sup.6 is aryl, optionally substituted; or X=O and R.sup.6 is (R.sup.7, R.sup.8, R.sup.9)Si; wherein R.sup.7, R.sup.8, R.sup.9 are alkyl or phenyl, optionally substituted; or X=O and R.sup.6 is (R.sup.10, R.sup.11, R.sub.12)C, wherein R.sup.10, R.sup.11, R.sup.12 are independently selected from phenyl, alkyl; optionally substituted; and to the catalysts used in the method.

The present invention discloses a homogenous cerium (Ce) catalyst composition comprising Ce(IV) complex alone, or Ce(IV) complex in a mixture with Ce(III) complex, that can significantly improve both LPG and soot combustion, resulting in higher flame temperatures, faster heating, reduced cooking time and reduced fuel consumption. The cerium(III) complex is cerium(III) 2-ethylhexanoate and the cerium(IV) complex is aqua(2-N-(2-hydroxyethylimino)-4-pentanoate) dinitrocerium(IV) [Ce(L1)(H.sub.2O)(NO.sub.3).sub.2], wherein L1 is 2-N-(2-hydroxyethylimino)-4-pentanone.

Metal-organic frameworks (MOFs) having inorganic nodes that comprise an octahedral Hf.sub.6 cluster capped by eight .sub.3-ligands and having twelve octahedral edges, wherein the .sub.3-ligands are hydroxo ligands, oxo ligands or aquo ligands; and organic linkers connecting the organic nodes, the organic linkers comprising 1,3,6,8-tetrakis(p-benzoic acid)pyrene units; wherein eight of the twelve octahedral edges of the inorganic nodes are connected to the 1,3,6,8-tetrakis(p-benzoic acid)pyrene units are provided.

The present invention relates to ligands based on calixarenes, metal complexes including such ligands and their use as homogeneous or heterogeneous catalysts.

This present invention relates to a catalyst composition for a production process of -lactone from carbon dioxide and 1,3-butadiene that can efficiently catalyze the synthesis reaction of -lactone with good selectivity of -lactone, wherein said catalyst composition comprising: a) palladium metal complexes as shown in structure (I) [Formula should be inserted here] wherein, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently represents a group selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an amine group, or optionally an alkenyl group, an alkynyl group, a phenyl group, a benzyl group, or a cyclic hydrocarbon group comprising a hetero atom; and b) phosphorus compound selected from a phosphine group having a general formula [Formula should be inserted here], wherein R is selected from an alkyl group, a cycloalkyl group, or an aryl group.

##STR00001##

The present invention concerns a process for the preparation of poly(limonene)dicarbonate (PLDC) from poly(limonene)carbonate, proceeding via the epoxidized intermediate, as well as the resulting PLDC products having an unusually high glass transition temperature.

The present invention relates to an oligomerization catalyst a transition metal or transition metal precursor, a halogen-substituted organic ligand, and a heteroatom ligand, and to a method for selectively preparing 1-hexene or 1-octene from ethylene using the catalyst.

A hydroprocessing catalyst or catalyst precursor has been developed. The catalyst is a unique transition metal tungsten oxy-hydroxide material. The hydroprocessing using the transition metal tungsten oxy-hydroxide material or the decomposition product thereof may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

A process for producing alpha-olefin dimers comprises contacting, at a temperature of 80 C. or more, a feedstock comprising at least one C.sub.8+ (linear) alpha-olefin with a catalyst system comprising activator and one or more catalyst compounds represented by the formula: ##STR00001##
where M is a Group 4 metal; n is 1, 2, or 3; R.sup.A is hydrogen or a C.sub.1 to C.sub.10 alkyl; each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 is independently selected from hydrogen and C.sub.1 to C.sub.10 alkyl; each X is independently selected from the group consisting of hydrocarbyl radicals having from 1 to 20 carbon atoms, hydrides, amides, alkoxides, sulfides, phosphides, halides, and a combination thereof, (two X's may form a part of a fused ring or a ring system), the contacting being conducted under conditions effective to oligomerize at least part of C.sub.8+ alpha-olefin to produce an oligomerized product containing at least 30 wt % of the alpha-olefin dimer and at least 80 mol % of vinylidene unsaturation, where the conversion of the alpha olefin is at least 10 wt %, based upon the weight of the alpha olefin monomer entering the reactor and the weight of dimer produced.

A method is provided of forming an olefin from a first olefin and a second olefin in a metathesis reaction, comprising reacting the first olefin with the second olefin in the presence of a compound that catalyzes the metathesis reaction such that the molar ratio of the compound to the first or the second olefin is from 1:500 or less, and the conversion of the first or the second olefin to the olefin is at least 30%.