In a ruthenium complex compound according to the present invention, an NHC ligand has an excellent electron-donating ability to stabilize methylidene species due to the steric interaction between substituents having relatively different sizes. The ruthenium complex compound can improve selectivity when used as a catalyst due to having an asymmetric structure, and the activity of the ruthenium complex compound can be improved by adjusting substituents and additives. Accordingly, the ruthenium complex compound can be used as a catalyst in cross metathesis reactions including ethenolysis to produce desired compounds such as linear ?-olefins at high yield, even under relatively mild conditions.

The present disclosure provides compounds, compositions, and methods for preparing alkenyl halides and/or haloalkyl-substituted olefins with Z-selectivity. The methods are particularly useful for preparing alkenyl fluorides such as CF.sub.3-substituted olefins by means of cross-metathesis reactions using halogen-containing molybdenum and tungsten complexes.

Provided are a transition metal compound including a novel carbene compound as a ligand, a preparation method thereof, and an application thereof. The transition metal compound according to the present invention may form a structurally stable complex and also have a HOMO-LUMO energy gap and singlet-triplet transition energy which are significantly low as compared with a conventional transition metal compound. In addition, according to the present invention, the transition metal compound may be synthesized in large quantities by a very simple method, thereby having high commercial utility, and thus, an application using the compound is expected.

The invention provides a new process for producing ruthenium complexes represented by the Formula 1. Invention provides also the use of ruthenium complexes represented by the Formula 1 as precatalysts and/or catalysts in olefin metathesis reactions.

Embodiments in accordance with the present invention encompass compositions encompassing a latent catalyst and a compound capable of generating a Bronsted along with one or more monomers which undergo ring open metathesis polymerization (ROMP) when said composition is exposed to a suitable radiation to form a substantially transparent film. The monomers employed therein have a range of refractive index from 1.4 to 1.6 and thus these compositions can be tailored to form transparent films of varied refractive indices. The composition of this invention also feature low dielectric constant (low k in the range of from about 2.2 to 3). Accordingly, compositions of this invention are useful in various opto-electronic applications, including as coatings, encapsulants, fillers, leveling agents, among others.

Nitrogen heterocyclic carbine ligands and ruthenium catalysts thereof, a preparation method therefor and an application thereof are provided. The structures of the nitrogen heterocyclic carbine ligands are represented by formulas Ia and Ib, respectively, and the corresponding ruthenium catalyst structures are represented by IIa and IIb, respectively. After simultaneously introducing large-steric hindrance and electron-rich groups into the described nitrogen heterocyclic carbine ligand structures, the catalytic activity, stability and application range of the ruthenium complex catalysts thereof are significantly improved. ##STR00001##

A method of producing polymer fibers and/or particles by direct polymerization of monomers without use of any external high energy sources (such as heat or UV) is described. The method may be used to fabricate polymer fibers, fiber mats, 3D polymer fiber structures, and polymer nano- and microparticles. Polymer fibers may be used to create fiber mats which can be utilized in a variety of applications.

A new family of mononuclear organometallic complexes of a divalent metal bound to sequential tetradentate monoanionic {ONNN}-type ligands, and polymerization of cyclic esters such as lactides utilizing same are provided. Novel tetradentate monoanionic {ONNN}-type ligands usable for forming these complexes are also provided.

The present invention refers to processes for catalytic reversible alkene-nitrile interconversion through controllable HCN-free transfer hydrocyanation.

The invention relates to immobilized metal alkylidene catalysts. The catalysts are useful in olefin metathesis.

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