Abstract: The invention relates to a method for preparation of ruthenium-based carbene catalysts with chelating alkylidene ligands (so-called “Hoveyda-type catalysts”) in a cross metathesis reaction by reacting a ruthenium-alkylidene complex with an olefin derivate in the presence of a polymer-supported cation-exchange resin (PSR) acting as a ligand (i.e. phosphine or amine) scavenger. Preferably, penta-coordinated ruthenium benzylidene or indenylidene carbene complexes are employed. The polymer-supported cation-exchange resin (PSR) may be an acidic resin (comprising sulfonic acid or carboxylic groups) or a resin containing carboxylic acid chloride (—COCl) groups or sulfonyl chloride (—SO2Cl) groups. The process is versatile and environmentally friendly; high yields are obtained.

Abstract: Improved catalysts useful in alkyne or olefin metathesis are made by bringing into contact a multi-coordinated metal complex comprising a multidentate Schiff base ligand, and one or more other ligands, with a selected activating compound under conditions such that at least partial cleavage of a bond between the metal and the multidentate Schiff base ligand of said metal complex occurs.

Abstract: The invention relates to a method for preparation of ruthenium-based carbene catalysts with chelating alkylidene ligands (so-called “Hoveyda-type catalysts”) in a cross metathesis reaction by reacting a ruthenium-alkylidene complex with an olefin derivate in the presence of a polymer-supported cation-exchange resin (PSR) acting as a ligand (i.e. phosphine or amine) scavenger. Preferably, penta-coordinated ruthenium benzylidene or indenylidene carbene complexes are employed. The polymer-supported cation-exchange resin (PSR) may be an acidic resin (comprising sulfonic acid or carboxylic groups) or a resin containing carboxylic acid chloride (—COCl) groups or sulfonyl chloride (—SO2Cl) groups. The process is versatile and environmentally friendly; high yields are obtained.

Abstract: This invention provides metal complexes being useful as catalyst components in metathesis reactions and in reactions involving the transfer of an atom or group to an ethylenically or acetylenically unsaturated compound or another reactive substrate and, with respect to a sub-class thereof, for the polymerisation of ?-olefins and optionally conjugated dienes, with high activity at moderate tempera-tures. It also provides methods for obtaining polymers with very narrow molecular weight distribution by means of a living reaction. It also provides methods for making said metal complexes and novel intermediates involved in such methods. It further provides derivatives of said metal complexes which are suitable for covalent bonding to a carrier, the product of such covalent bonding being useful as a supported catalyst for heterogeneous catalytic reactions. It also provides a direct one-step synthesis of pyrrole, furan and thiophene compounds from diallyl compounds.

Abstract: A nozzle for injecting fuel into a combustion zone including a stationary nozzle body having a main fuel passage therethrough connected to a source of fuel under pressure, an auto-rotating tip disposed on the nozzle body for rotation about a main axis of the latter, a fuel distribution cavity between the tip and the nozzle body connected to the main fuel passage and filled with pressurized fuel, and a plurality of fuel passages in the tip exposed to pressurized fuel in the distribution cavity. Each of the fuel passages is disposed in a plane perpendicular to the main axis and is slanted relative to one of a corresponding plurality of radii emanating from the main axis so that jets of fuel issuing from the fuel passages develop reaction forces on the tip having components tangent to a circle about the main axis which reaction forces spin the tip to disperse fuel in the combustion zone in a volume of revolution about the main axis.

Abstract: A low emission combustor assembly particularly suited for an automotive gas turbine engine has an inlet plenum supplied with regenerated compressor discharge, an exhaust plenum, a diffusion flame combustion chamber disposed between the inlet and exhaust plenums, and a catalytic combustion chamber also disposed between the inlet and exhaust plenums so that parallel flow paths are established between the inlet and exhaust plenums. During engine start-up, fuel is supplied only to the diffusion flame combustion chamber and regenerated compressor discharge simultaneously flowing through the catalytic combustion chamber heats the catalyst to operating temperature and cools and dilutes exhaust from the diffusion flame combustion chamber.

Abstract: An improved gas turbine engine combustor assembly particularly for automotive application including a primary reaction chamber disposed in a pressurized air plenum of the engine, fixed area air flow ports between the reaction chamber and the plenum, a prechamber housing at an upstream end of the reaction chamber having an annular fixed area air passage between the plenum and the reaction chamber, a radially expandable annular partition in the air passage dividing the latter into an inner annular prechamber portion and an outer annular excess air portion, and a fuel nozzle operative to spray fuel into the prechamber portion where it vaporizes and mixes with air passing through the prechamber portion to provide a combustible mixture of properly lean air-fuel ratio in the combustor. The flow areas of the prechamber portion and the excess air portion vary in mutually inverse relationship and combine to always substantially equal the flow area of the air passage.

Abstract: A combustion method and apparatus for gas turbine engines employs a combustion process and combustion liner structure adapted to promote complete combustion of liquid hydrocarbon fuel and minimize undesired combustion products. Compressed primary air flows radially inward into a prechamber into which fuel is sprayed. Except during start-up, the air is heated. Normally, the air mixes with and evaporates the fuel and the mixture flows through a throat into a reaction chamber. The upstream end of the reaction chamber is bounded by a biconical annular wall, the inner radial portion of which diverges sharply and the outer radial portion of which diverges less sharply. The liner wall downstream of the throat defines the reaction zone and a dilution zone to which secondary air is admitted. The areas of both the primary and the secondary air entrances are variable to maintain a lean fuel-air ratio in the reaction zone throughout the operating regime.The swirl angle of the entering primary air is variable.