Abstract: A hydrogenation catalyst is used for the catalytic hydrogenation of an ester-containing aldehyde mixture and the catalyst contains a ?-alumina having a BET surface area of from 70 to 350 m2/g as support material, and at least one component having hydrogenation activity and being selected from the group consisting of nickel, cobalt and mixtures thereof.

Abstract: The invention is directed to liquid vegetable unsaturated alcohol mixture having an iodine value of 88 to 100 and a cloud point less than 7° C., the unsaturated alcohol mixture being prepared by reduction of a vegetable unsaturated fatty acid mixture and/or an alkyl ester thereof in the presence of a zinc-type catalyst having a copper content of 30 ppm or less, the vegetable unsaturated fatty acid mixture being prepared from at least one vegetable oil selected from the group consisting of palm oil, coconut oil and palm kernel oil. The invention also concerns a liquid vegetable unsaturated alcohol mixture having an iodine value of 88 to 100, a cloud point less than 7° C. or lower and a conjugated diene content of 1 wt. % or less.

Abstract: The present invention relates to a process for the production of iso-propanol by liquid phase hydrogenation of acetone to iso-propanol in at least two hydrogenation reaction stages, each reaction stage comprising a hydrogenation reaction zone, wherein the hydrogenation reaction product leaving the reaction zone of the first reaction stage contains unreacted acetone and a product stream comprising acetone and iso-propanol is transferred to the reaction zone of a subsequent reaction stage said product stream having at the inlet to the reaction zone of said subsequent reaction stage a temperature of 60 to 100° C., wherein the temperature of the product stream leaving the reaction zone of said subsequent reaction stage at the outlet from said reaction zone is at most 40° C. higher than the temperature of the product stream entering said reaction zone at the inlet to said reaction zone and the temperature in said subsequent reaction zone does not exceed 125° C.

Abstract: The invention relates to the preparation of enantiomerically pure (S)-1,1,1-trifluoro-2-propanol by asymmetric hydrogenation of 1,1,1-trifluoroacetone which process comprises hydrogenating 1,1,1-trifluoroacetone in the presence of a ruthenium phosphine complex catalyst represented by formula Ru(E)(E?)(L)(A) wherein E, E? are both chloro or E is hydrogen and E? is BH4; L is a chiral diphosphine ligand; and A is an optionally chiral diamine wherein hydrogenation occurs in the presence of a weak base, with or without an additive, when E and E? are both chloro or b) in the absence of a base and an additive when E and E? are hydrogen and BH4.

Abstract: The present invention provides an asymmetric reduction catalyst effective in preparing optically-active alcohol compounds having various functional groups, and a process for preparing optically-active alcohol compounds using said asymmetric reduction catalyst. The organic metal compound of the present invention is represented by the following general formula (1): wherein R1 and R2 may be mutually identical or different, and are an alkyl group, a phenyl group, a naphthyl group, a cycloalkyl group, or an alicyclic ring formed by binding R1 and R2, which may have a substituent; R3 is a hydrogen atom or an alkyl group; Cp is a cyclopentadienyl group, which may have a substituent, bound to M1 via a ? bond; X1 is a halogen atom or a hydrido group; M1 is rhodium or iridium; and * denotes asymmetric carbon.

Abstract: Methods and systems for the hydrogenation of aldehydes and/or ketones are described herein. The methods and systems incorporate the novel use of a high shear device to promote dispersion and solubility of the hydrogen-containing gas (e.g. H2 gas) in the aldehydes and/or ketones. The high shear device may allow for lower reaction temperatures and pressures and may also reduce hydrogenation time with existing catalysts.

Abstract: A novel transition metal complex, preferably a ruthenium-phosphine complex or rhodium-phosphine complex, which is effectively usable in various asymmetric syntheses and, in particular, is more effectively usable in the asymmetric hydrogenation of various ketones; and a novel process for producing an optically active alcohol with the complex. The novel transition metal complex includes a ligand obtained by introducing a diarylphosphino group into each of the 2- and 2?-positions of diphenyl ether, benzophenone, benzhydrol, or the like. It preferably further includes an optically active 1,2-diphenylethylenediamine coordinated thereto. The complex preferably is a novel diphosphine-ruthenium-optically active diamine complex or diphosphine-rhodium-optically active diamine complex. The process comprises using the complex as an asymmetric hydrogenation catalyst to conduct the asymmetric hydrogenation of a ketone compound to thereby obtain an optically active alcohol in a high optical purity and a high yield.

Abstract: The present disclosure relates to a process for the reduction of compounds comprising one or more carbon-oxygen (C?O) double bonds, to provide the corresponding alcohol, comprising contacting the compound with hydrogen gas at a pressure greater than 3 atm and a catalyst comprising an iridium aminodiphosphine complex.

Abstract: Disclosed is a method for the catalytic hydrogenation of methylol alkanals of general formula (I), where R1 and R2 independently represent an additional methylol group or an alkyl group having with 1 to 22 carbon atoms, or an alkyl group with 1 to 22 C atoms, or an aryl group or aralkyl group with 6 to 33 carbon atoms, in the liquid phase on a hydrogenation catalyst. The inventive method is characterized in that a pH value ranging between 6.3 and 7.

Abstract: The invention relates to a new class of ruthenium (II) complexes containing as ligands 2-(aminomethyl)pyridines and phosphines, proven to be extremely active catalysts in the reduction of ketones to alcohols via hydrogen transfer. By using 2-propanol as the hydrogen source with the ruthenium complexes, high yields of the corresponding alcohol can be rapidly obtained starting from linear and cyclic alkyl aryl, dialkyl and diaryl ketones. The conversion of ketones to alcohols can reach 100% if operating in a gaseous hydrogen atmosphere (2-3 atm). Where the phosphines used are optically active, starting from prochiral ketone compounds various types of optically active alcohols can be produced, being important intermediates in the pharmaceutical industry, in the agrochemical industry and for fine chemicals generally.

Abstract: A sulfonate catalyst represented by the formula below and a ketone compound are placed in a solvent, and the ketone compound is hydrogenated by mixing in the presence of hydrogen to produce an optically active alcohol.

Abstract: The present invention relates to a process for hydrogenating an aldehyde. An aldehyde is contacted with a catalyst comprising a support containing at least 95% ?-alumina and non-support metals dispersed on the surface of the support. The non-support metals comprise nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof. The nickel and/or one or more compounds thereof comprise from 3 wt. % to 9 wt. % of the catalyst, by metallic weight, and the molybdenum and/or one or more compounds thereof comprise from 1 wt. % to 4 wt. % of the catalyst, by metallic weight.

Abstract: A tert-alkyl ketone, pinacolone was hydrogenated under pressurized hydrogen in the presence of a ruthenium complex (S)-1 and a base, and corresponding (S)-3,3,-dimethyl-2-butanol was thereby obtained in 100% yield and 97% ee

Abstract: Processes for producing branched compounds are described wherein a carbonyl compound is condensed in the presence of a catalyst selected from the group consisting of acids and bases, to form an ?,?-unsaturated condensation product; and the ?,?-unsaturated condensation product is hydrogenated.

Abstract: The present invention provides a hydrogenation catalyst effective for hydrogenating 3-hydroxypropionaldehyde to 1,3-propanediol. The hydrogenation catalyst comprises an ?-alumina support, nickel, ruthenium, and a promoter. The nickel is deposited on the ?-alumina support, and the ruthenium and the promoter are deposited on the nickel and the ?-alumina support. The ?-alumina support comprises at least 92 wt. % of the catalyst, and the nickel comprises from 1 wt. % to 6 wt. % of the catalyst. The present invention also provides a process of hydrogenating 3-hydroxypropionaldehyde to 1,3-propanediol with the catalyst.

Abstract: The invention relates to the preparation of enantiomerically pure (S)-1,1,1-trifluoro-2-propanol by asymmetric hydrogenation of 1,1,1-trifluoroacetone which process comprises hydrogenating 1,1,1-trifluoroacetone in the presence of a ruthenium phosphine complex catalyst represented by formula Ru(E)(E)(L)(A) wherein E, E? are both chloro or E is hydrogen and E? is BH4; L is a chiral diphosphine ligand; and A is an optionally chiral diamine wherein hydrogenation occurs in the presence of a weak base, with or without an additive, when E and E? are both chloro or b) in the absence of a base and an additive when E and E? are hydrogen and BH4.

Abstract: The catalysts of formula (II): [Ru(L)m(L?)wXY], wherein X and Y represent simultaneously or independently a hydrogen or halogen atom, a hydroxy group, or an alkoxy, carboxyl or other anionic radical, m is 1 or 2, w is 1 when m is 1 and w is 0 when m is 2, L is a phosphino-amine or phosphino-imine bidentate ligand and L? a diphosphine, are useful for the hydrogenation of substrates having a carbon-hetero atom double bond.

Abstract: The invention relates to a process for the reduction of compounds comprising a carbon-carbon (C?C), carbon-oxygen (C?O), or carbon-nitrogen (C?N) double bond, to a corresponding hydrogenated alkane, alcohol or amine, comprising contacting a compound comprising the C?C, C?O or C?N double bond with a hydrogen donor solvent and a catalyst comprising a metal complex having a tridentate aminodiphosphine ligand under transfer hydrogenation conditions.

Abstract: The invention pertains to a hydroformylation process for the conversion of an ethylenically unsaturated compound to an alcohol comprising a first step of reacting at an elevated temperature in a reactor the ethylenically unsaturated compound, carbon monoxide, hydrogen, and a phosphine-containing cobalt hydroformylation catalyst, which are dissolved in a solvent, followed by a second step of separating a mixture comprising the alcohol and heavy ends from a solution comprising the catalyst and the solvent, followed by a third step of recycling the solution to the reactor.

Abstract: Process for the preparation of enantiomerically enriched amino aldehydes and amino alcohols, wherein a corresponding enantiomerically enriched amino nitrile is subjected to hydrogenation in the presence of hydrogen, a hydrogenation catalyst, preferably a Pd-catalyst and a mineral acid. For the preparation of an amino aldehyde hydrogen preferably is present at a hydrogen-pressure between 0.1 and 2 MPa, in particular between 0.5 and 1 MPa. The amino aldehyde preferably is isolated in the form of a chemically and configurationally stable derivative. For the preparation of an amino alcohol, preferably at least during part of the hydrogenation hydrogen is present at a hydrogen-pressure between 2 and 10 MPa, in particular between 4 and 6 MPa. In a preferred embodiment the hydrogen-pressure initially is between 0.5 and 2 MPa and subsequently, after most of the nitrile starting material is converted, the hydrogen pressure is increased to a value between 2 and 10 MPa.

Abstract: Alkyl-substituted butenols having the formula (I): R1—CH2—CH?CR2—CH2OH ??(I) wherein R1 is a saturated or olefinically unsaturated alkyl or cycloalkyl group having from 4 to 16 carbon atoms and wherein R1 is optionally substituted by an alkyl, cycloalkyl, aryl or alkaryl having up to 12 carbon atoms; R2 is hydrogen or an alkyl group having from 1 to about 6 carbon atoms are produced by a process which comprises: (1) reacting an aldehyde of the formula (II): R1—CH2—CHO ??(II) wherein R1 has the same meaning as in formula (I), with the corresponding lower aldehyde to form an unsaturated aldehyde in an inert organic solvent; (2) continuously contacting an optionally calcined copper/zinc catalyst with the unsaturated aldehyde under isothermal conditions at temperatures of from about 45 to about 60° C. and under a hydrogen pressure of from 1 to about 300 bar.

Abstract: A process for preparing aliphatic alcohols that includes cobalt-catalyzed hydroformylation of olefins, treatment of a hydroformylation mixture with oxygen-containing gases in the presence of acidic, aqueous cobalt(II) salt solutions, separation of a mixture into an aqueous phase comprising cobalt salts and an organic phase comprising the aliphatic aldehydes, and hydrogenation of an aldehyde-containing organic phase wherein the organic phase and treatment with an adsorbent to separate off cobalt compounds prior to hydrogenation.

Abstract: The present invention relates to a process for preparing a C13-alcohol mixture which is suitable, in particular, as precursor for the preparation of compounds having surfactant properties and of plasticizers.

Abstract: A transition metal complex having 2,2?-bis[bis(3,5-di-tert-butyl-4-methoxyphenyl)phosphino]-1,1?-binaphthyl as a ligand. The presence of the transition metal complex in the reaction system of an asymmetric reaction system allows the preparation of an objective compound having an objective absolute configuration with improved efficiency.

Abstract: A process for producing primary alcohols from secondary alcohols and/or tertiary alcohols and/or ketones, wherein the process comprises reacting a compound selected from a secondary alcohol, a tertiary alcohol, a ketone, or mixtures thereof, with carbon monoxide and hydrogen in the presence of a catalyst based on: (i) a source of Group VIII metal, (ii) a bidentate ligand having the general formula (I): R1R2M1-R-M2R3R4??(I) wherein M1 and M2 are independently P, As or Sb; R1 and R2 together represent a bivalent substituted or unsubstituted cyclic aliphatic group whereby the two free valencies are linked to M1; R3 and R4 independently represent a substituted or unsubstituted hydrocarbyl group, or together represent a bivalent or non-substituted cyclic group whereby the two free valencies are linked to M2; and R represents a bivalent aliphatic bridging group; and (iii) an acid having a pKa of 3 or less which is in excess over the Group VIII metal.

Abstract: A process for the hydrogenation of an organic compound containing at least one carbonyl group comprises bringing the organic compound in the presence of hydrogen into contact with a shaped body which can be produced by a process in which (i) an oxidic material comprising copper oxide, zinc oxide and aluminum oxide is made available, (ii) pulverulent metallic copper or pulverulent cement or a mixture thereof is added to the oxidic material, and (iii) the mixture resulting from (ii) is shaped to form a shaped body.

Abstract: A process for making technical oleic acid methyl esters having a stearic acid methyl ester content of less than about 2% by weight, and a palmitic acid methyl ester content of less than about 5%, comprising: (a) providing a C8-18 palm kernel oil fatty acid methyl ester; (b) fractionally distilling said C8-18 palm kernel oil fatty acid methyl ester to form a C8-14 head product and a C16-18 bottom product; (c) fractionally distilling the C16-18 bottom product to form a short-chain C16 head product and a long-chain and unsaturated C18 bottom product; (d) fractionally distilling the long-chain and unsaturated C18 bottom product to form a predominantly unsaturated head product having a high palmitic acid methyl ester content and a predominantly unsaturated bottom product have a minimal palmitic acid methyl ester content; and (e) fractionally distilling the predominantly unsaturated bottom product have a minimal palmitic acid methyl ester content to form a head product rich in oleic acid methyl ester and poor in st

Abstract: The invention is directed to a continuous hydrogenation process in which a hydrogenable compound is dissolved in a working solution with hydrogen and a heterogeneous catalyst. At least part of the hydrogen-containing waste hydrogenation gas generated in the reaction is compressed and then recycled into the hydrogenation reactor. A jet pump is used for the compression of the waste hydrogenation gas and a liquid or gaseous feedstock of the hydrogenation process is used as the motive agent. Preferred motive agents are the hydrogenation gas or a working solution recycled into the process. The process is particularly suitable for performing the hydrogenation step in the anthraquinone process for the production of hydrogen peroxide.

Abstract: This invention relates to an improvement in a liquid phase process for producing isopropanol by the hydrogenation of acetone in the presence of a hydrogenation catalyst; the improvement comprising; contacting acetone with hydrogen under continuous liquid phase conditions; and, employing a sponge metal catalyst promoted with an effective amount of chromium.

Abstract: A process is described for selectively hydrogenating citronellal to citronellol in which a liquid phase, in which the citronellal is dissolved and particles of a catalyst are suspended which is capable of preferentially hydrogenating carbon-oxygen double bonds over carbon—carbon double bonds, is conducted through a device which inhibits the transport of the catalyst particles in the presence of a hydrogen-containing gas.

Abstract: Organometallic complexes are provided, which include a catalyst containing a transition metal, a ligand and a component having the formula GArF. ArF is an aromatic ring system selected from phenyl, naphthalenyl, anthracenyl, fluorenyl, or indenyl. The aromatic ring system has at least a substituent selected from fluorine, hydrogen, hydrocarbyl or fluorinated hydrocarbyl, G is substituted or unsubstituted (CH2)n or (CF2)n, wherein n is from 1 to 30, wherein further one or more CH2 or CF2 groups are optionally replaced by NR, PR, SiR2, BR, O or S, or R is hydrocarbyl or substituted hydrocarbyl, GArF being covalently bonded to either said transition metal or said ligand of said catalyst, thereby rendering said cationic organometallic complex liquid.

Abstract: Disclosed are ruthenium complexes of phosphine-aminophosphine ligands that may be used to catalyze large number of reactions of a wide variety of substrates such as asymmetric hydrogenations, asymmetric reductions, asymmetric hydroborations, asymmetric olefin isomerizations, asymmetric hydrosilations, asymmetric allylations, and asymmetric organometallic additions. Also disclosed is a process for the preparation of the ruthenium complexes and processes for the enantioselective asymmetric hydrogenations of 1,3-dicarbonyl, ?-hydroxycarbonyl, and ?-hydroxycarbonyl compounds to produce the corresponding hydroxycarbonyl, 1,2-diol, and 1,3-diol compounds, respectively, using the ruthenium complexes to catalyze the hydrogenation.

Abstract: Process for the preparation of isopropanol is provided, wherein a benzene-containing feed of acetone is hydrogenated to obtain isopropanol and hydrogenation products of benzene. Combination of such a process with a process for the preparation of phenol and combination of such a process with a series of separation steps is provided.

Abstract: Acetone is hydrogenated by a process comprising, conducting the liquid-phase hydrogenation of acetone in at least two hydrogenation process stages, thereby preparing isopropanol product with a high selectivity and in high purity.

Abstract: The present invention relates to a continuous process for the selective hydrogenation of olefinically unsaturated carbonyl compounds to give unsaturated alcohols in particular of citral to give a mixture of geraniol and nerol, in a reactor containing a liquid phase, in which at least one catalyst is suspended, and which can additionally contain a gas phase, wherein the liquid phase and, if present, the gas phase are passed through a device in the reactor having openings or channels.

Abstract: In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.

Abstract: The invention relates to novel diphosphines, in optically pure or racemic form, of formula (I): in which: R1 and R2 are a (C5-C7)cycloalkyl group, an optionally substituted phenyl group or a 5-membered heteroaryl group; and A is (CH2—CH2) or CF2. The invention further relates to the use of a compound of formula (I) as a ligand for the preparation of a metal complex useful as a chiral catalyst in asymmetric catalysis, and to the chiral metal catalysts comprising at least one ligand of formula (I).

Abstract: A process for the hydrogenation of acetone to prepare isopropanol is provided, wherein the hydrogenation reaction is carried out in a multi-tubular reactor.

Abstract: A process for the hydrogenation, using molecular hydrogen (H2) of a catalytic system, wherein the catalytic system includes a base and a complex of formula (II): Ru(P2N2)Y2??(II) wherein Y represent simultaneously or independently a hydrogen or halogen atom, a hydroxy group, or an alkoxy, carboxyl or other anionic radical, and P2N2 is a tetradentate diimino-diphosphine ligand.

Abstract: The present invention relates to a process for producing aliphatic C3-C10-alcohols, in particular 2-ethylhexanol, from high boilers by thermal treatment in the presence of an alkali metal compound and subsequent hydrogenation of the volatile products.

Abstract: A supported catalyst comprises a cationic rhodium(I) complex of the formula wherein R1 and R2 are the same or different hydrocarbon groups of up to 30 C atoms, or R1 and R2 are linked to form a ring, and a heterogeneous support medium that provides anionic binding sites. Such a complex is particularly useful as a catalyst in a process of hydrogenating an aldehyde to produce the corresponding primary alcohol.

Abstract: Disclosed is a method for the preparation of cumene by reacting isopropanol or a mixture of isopropanol and propene with benzene in the presence of a ?-zeolite catalyst having a SiO2/Al2O3 molar ratio greater than 10:1 that can be integrated in a process for preparing phenol, which comprises preparing cumene as described above, oxidizing cumene to cumene hydroperoxide, acid-catalyzed cleavage of cumene hydroperoxide to give phenol and acetone, and hydrogenating acetone to form isopropanol.

Abstract: The invention concerns an oxazaborolidine compound fixed on a material selected among Raney nickel, Raney cobalt and Raney iron, the method for preparing same, and the use of the compound as reduction reaction catalyst of ketone to produce chiral alcohols.

Abstract: Platinum-free chelate catalyst materials for the selective reduction of oxygen have application in hydrogen and methanol fuel cells. Conventional catalyst material comprises an unsupported transition metal and a nitrogen- and a carbon-donor, which are polymerized to give a carbon matrix under pyrolytic conditions, in which the unsupported transition metal, functioning as electron donor and a nitrogen-coordinated transition metal chelate are bonded. The achievable porosity, catalytic activity, and stability are, however, not adequate for commercial applications. Said chelate catalyst material comprises, in addition to the at least one unsupported transition metal, a nitrogen-containing organo-metallic transition complex, with a further transition metal different from the said transition metal and a chalcogenic component. The advantages of various transition metals and the chalcogens as electrically conducting bridge-formers can thus be combined.

Abstract: The present invention relates to a novel process for producing a &dgr;-lactone of the formula: using an acyl halide of the formula: wherein R1, R2 R3 and X are described herein, as well as novel intermediates. In particular, the present invention relates to a process for enantioselectively producing the (R)-&dgr;-lactone.

Abstract: The invention provides novel ruthenium complexes having an optically active diphosphine compound, which has asymmetry on carbon and is easy to synthesize, as the ligand and a process for preparing optically active alcoholic compounds using said complexes as the catalysts, wherein said process is the process for preparing optically active alcoholic compounds, which are excellent in terms of reactivity, enatioselectivity and the like in an asymmetric hydrogenation of carbonyl compounds compared with conventional ruthenium complex catalysts having an optically active diphosphine compound having the axial chirality or the asymmetry on carbon as the ligand.

Abstract: The invention relates to a process for the preparation of saturated C3-C20-alcohols in which a liquid hydrogenation feed comprising at least one C3-C20-aldehyde is passed over a bed of a hydrogenation catalyst in the presence of a hydrogen-containing gas, which comprises adding to the hydrogenation feed an amount, homogeneously soluble therein, of a salt-like base. The addition of base suppresses side reactions, such as acetalization, aldolization, Tischtschenko reaction or ether formation.

Abstract: The present invention relates to the co-production of unsaturated aldehydes via a crossed-aldol condensation reaction catalyzed by recyclable water-soluble phase-transfer catalysts or the hydroxides thereof. The aldehydes are then hydrogenated to the desired alcohol products or saturated aldehyde feed stocks. Specifically, methods in which 2,4-diethyloctanol is co-produced with 2-ethylhexanol in batch and continuous processes are described. Recovery of the phase-transfer catalyst through water washing followed by “salting out” from the washings is also demonstrated.

Abstract: A method is described for stereoselectively reducing an unsaturated alkyl ketone substituent attached to a fused ring base. In this method, the unsaturated alkyl ketone reacts with a chiral oxazaborolidine reagent. This reaction stereoselectively reduces the unsaturated alkyl ketone to an unsaturated alkyl alcohol. The unsaturated alkyl alcohol can be further reduced, if desired, to produce a saturated alkyl alcohol. The fused ring base can be, for example, a steroid ring base or a base of a vitamin D analog. The process in accordance with the invention can be used with an alkeneone substituent (e.g., a 22-ene-24-one substituent) or an alkyneone substituent (e.g., a 22-yne-24-one substituent) on a steroid ring base to make squalamine or other useful aminosterol compounds and intermediates for making aminosterol compounds.

Abstract: A compound is provided including an organometallic complex represented by the formula I: [CpM(CO)2(NHC)Lk]+A−  I wherein M is an atom of molybdenum or tangsten, Cp is substituted or unsubstituted cyclopentadienyl radical represented by the formula [C5Q1Q2Q3Q4Q5], wherein Q1 to Q5 are independently selected from the group consisting of H radical, C1-20 hydrocarbyl radical, substituted hydrocarbyl radical, halogen radical, halogen-substituted hydrocarbyl radical, —OR, —C(O)R′, —CO2R′, —SiR′3 and —NR′R″, wherein R′ and R″ are independently selected from the group consisting of H radical, C1-20 hydrocarbyl radical, halogen radical, and halogen-substituted hydrocarbyl radical, wherein said Q1 to Q5 radicals are optionally linked to each other to form a stable bridging group, NHC is any N-heterocyclic carbene ligand, L is either any neutral electron donor ligand, wherein k is a number from 0 to 1 or L