This invention relates generally to olefin metathesis catalysts, to the preparation of such compounds, compositions comprising such compounds, methods of using such compounds, and the use of such compounds in the metathesis of olefins and in the synthesis of related olefin metathesis catalysts. The invention has utility in the fields of catalysis, organic synthesis, polymer chemistry, and in industrial applications such as oil and gas, fine chemicals and pharmaceuticals.

Gold (I) complexes that can absorb light in the near-UV and/or visible regions and methods of making and using thereof are described. These gold (I) complexes have photochemical reactivities, such as strong absorption of near-UV and/or visible light, quenching rate constants ≥3.5×10.sup.5 s.sup.−1, etc., that allow them to catalyze photoredox reactions, such as homocoupling of organic halides (e.g. alkyl halides and aryl halides), alkylation of 2-phenyl-1,2,3,4-tetrahydroisoquinoline, cyclization of indoles, reductive dehalogenation of aryl halides, and/or C—H bonds cleavage, under near-UV and/or visible light. The product of a photo-induced organic reaction catalyzed by the gold (I) complexes described herein can have a yield that is higher than the yield of the same product formed from the same reaction under the same reaction conditions, using the same loading or a higher loading of [Au.sub.2(μ-dppm).sub.2](Cl).sub.2, [Ru(bpy).sub.3](Cl).sub.2, and/or [fac-Ir(ppy).sub.3] compared to the loading of the one or more gold (I) complex(es).

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 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 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 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 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 porphyrin-based catalysts for water splitting are composites of porphyrin or metalloporphyrin active ingredients, conductive carbon (e.g., graphene sheets, vapor grown carbon fiber, carbon black, etc.), and a polymer or binder that may be coated on a glassy carbon electrode. The polymer or binder may be Nafion oil or polyvinylidine difluoride. The porphyrin may be a porphyrin having a transition metal or hydrogen at its center, and may be halogenated and/or have a thiophene substituent.

This invention relates generally to olefin metathesis catalysts, to the preparation of such compounds, compositions comprising such compounds, methods of using such compounds, and the use of such compounds in the metathesis of olefins and in the synthesis of related olefin metathesis catalysts. The invention has utility in the fields of catalysis, organic synthesis, polymer chemistry, and in industrial applications such as oil and gas, fine chemicals and pharmaceuticals.

Triaryl phosphine ligands, as shown in general formulae Ia and Ib, or a mixture thereof, and a preparation method therefor. The invention addresses the deficiencies of biaryl phosphine ligands invented by Buchwald et al. Also provided are a triaryl phosphine coordinated palladium complex, a system composed of triaryl phosphine ligand and a palladium salt or complex, and a use of the triaryl phosphine coordinated palladium complex in catalysing organic reactions, in particular a use in catalysis of coupling reactions involving (pseudo)halogenated aromatic hydrocarbon as substrate.