Ruthenium Trichloride Catalyst in Water: Ru Colloids versus Ru Dimer Characterization Investigations.

An easy-to-prepare ruthenium catalyst obtained from ruthenium(III) trichloride in water demonstrates efficient performances in the oxidation of several cycloalkanes with high selectivity toward the ketone. In this work, several physicochemical techniques were used to demonstrate the real nature of the ruthenium salt still unknown in water and to define the active species for this Csp-H bond functionalization. From transmission electron microscopy analyses corroborated by SAXS analyses, spherical nanoobjects were observed with an average diameter of 1.

Odyssey in Polyphasic Catalysis by Metal Nanoparticles.

Nanometer-sized metal particles constitute an unavoidable family of catalysts, combining the advantages of molecular complexes in regards to their catalytic performances and the ones of heterogeneous systems in terms of easy recycling. As part of this research, our group aims at designing well-defined metal nanoparticles based-catalysts, in non-conventional media (ionic liquids or water), for various catalytic applications (hydrogenation, dehalogenation, carbon-carbon coupling, asymmetric catalysis) in mild reaction conditions. In the drive towards a more eco-responsible chemistry, the main focuses rely on the search of highly active and selective nanocatalysts, in association with an efficient recycling mainly under pure biphasic liquid-liquid conditions.

Calcium trifluoroacetate as an efficient catalyst for ring-opening of epoxides by amines under solvent-free conditions.

Ca(CF3CO2)2 efficiently catalyzed the selective ring-opening of epoxides by amines leading to the synthesis of β-aminoalcohols. The reaction works well with various aromatic and aliphatic amines under solvent-free conditions. Corresponding β-aminoalcohols were obtained in excellent yields with high regioselectivity.

Cyclodextrins as growth controlling agents for enhancing the catalytic activity of PVP-stabilized Ru(0) nanoparticles.

Cyclodextrins act as growth controllers in the synthesis of PVP-stabilized Ru(0) nanoparticles, leading to enhancement of the catalytic activity in the hydrogenation of furfural.

Chiral ammonium-capped rhodium(0) nanocatalysts: synthesis, characterization, and advances in asymmetric hydrogenation in neat water.

Optically active amphiphilic compounds derived from N-methylephedrine, N-methylprolinol, or cinchona derivatives possessing bromide or chiral lactate counterions were efficiently used as protective agents for rhodium(0) nanoparticles. The full characterization of these surfactants and the obtained nanocatalysts was performed by means of different techniques. These spherical nanoparticles, with sizes between 0.

New ammonium surfactant-stabilized rhodium(0) colloidal suspensions: influence of novel counter-anions on physico-chemical and catalytic properties.

Novel anionic species, such as hydrogen carbonate (HCO(3)(−)), fluoride (F(−)), triflate (CF(3)SO(3)(−)), tetrafluoroborate (BF(4)(−)) and chloride (Cl(−)) were investigated as new partners of water soluble N,N-dimethyl-N-cetyl-N-(2-hydroxyethyl) ammonium salts, used as a protective agent of rhodium colloids. The effect of the surfactant polar head on the micellar behavior, size and morphology of the nanospecies was studied by adapted physico-chemical experiments (surface tension measurements, dynamic light scattering, thermogravimetric and TEM analyses) and discussed in terms of strong or weak stabilization of the growing nanoparticles surface. Finally, the influence of the nanoenvironment generated by the surfactant with various counter-anions was evaluated via the hydrogenation of aromatics.

N-donor ligands based on bipyridine and ionic liquids: an efficient partnership to stabilize rhodium colloids. Focus on oxygen-containing compounds hydrogenation.

Polynitrogen ligands and/in ionic liquids (ILs) are described as a pertinent tandem to efficiently stabilize rhodium nanoparticles (NPs) in the size range of 2.0 nm for catalytic applications. Several N-donor ligands based on bipyridine skeleton were used as extra protective agents in [BMI][PF(6)] and compared in the hydrogenation of functionalized aromatic compounds at 80 °C and under 40 bar H(2).

Using click chemistry to access mono- and ditopic β-cyclodextrin hosts substituted by chiral amino acids.

A wide range of chiral mono- and ditopic cyclodextrin-based receptors have been synthesized by CuI-catalyzed azide-alkyne cycloaddition starting from mono-6-azido-β-cyclodextrin and chiral amino acids. Of interest, microwaves proved very efficient to access a wide range of ditopic β-cyclodextrin receptors with quantitative yields.

Polyhydroxylated ammonium chloride salt: a new efficient surfactant for nanoparticles stabilisation in aqueous media. Characterization and application in catalysis.

A trihydroxyammonium chloride has proved to be an efficient protective agent for Rh(0) nanoparticles and the hydrogenation of arene compounds has been investigated. Significant formation of cyclohexanone in the reduction of anisole has been demonstrated.

Carbohydrate-derived 1,3-diphosphite ligands as chiral nanoparticle stabilizers: promising catalytic systems for asymmetric hydrogenation.

Metallic Ru, Rh, and Ir nanoparticles were prepared by the decomposition of organometallic precursors under H(2) pressure in the presence of 1,3-diphosphite ligands, derived from carbohydrates, as stabilizing agents. Structural modifications to the diphosphite backbone were found to influence the nanoparticles' size, dispersion, and catalytic activity. In the hydrogenation of o- and m-methylanisole, the Rh nanoparticles showed higher catalytic activity than the corresponding Ru nanoparticles.

Catalytically active nanoparticles stabilized by host-guest inclusion complexes in water.

Hydrogenation of arene derivatives can be successfully performed in water by using ruthenium(0) nanoparticles stabilized by 1 : 1 inclusion complexes formed between methylated cyclodextrins and an ammonium salt bearing a long alkyl chain.

Rhodium nanocatalysts stabilized by various bipyridine ligands in nonaqueous ionic liquids: influence of the bipyridine coordination modes in arene catalytic hydrogenation.

Rhodium nanoparticles stabilized by 2,2'-, 3,3'-, 4,4'-bipyridine ligands were prepared in various ionic liquids according to a chemical reduction approach. Zerovalent nanospecies in the size range of 2.0-2.

Diphosphite ligands derived from carbohydrates as stabilizers for ruthenium nanoparticles: promising catalytic systems in arene hydrogenation.

Ruthenium nanoparticles (RuNPs) were prepared through the hydrogenation of [Ru(COD)(COT)] (COD = 1,5-cyclooctadiene, COT = 1,3,5-cyclooctatriene) in the presence of diphosphites derived from carbohydrates as stabilizing agents, and interestingly, structural modifications of the diphosphite backbone were found to influence nanoparticle size and dispersity, as well as their catalytic activity in arene hydrogenation.

A surfactant-assisted preparation of well dispersed rhodium nanoparticles within the mesopores of AlSBA-15: characterization and use in catalysis.

Well dispersed and efficient Rh(0) hydrogenation catalysts were obtained by the reduction of Rh(III)-exchanged mesoporous aluminosilicates by sodium borohydride in the presence of N,N-dimethyl-N-cetyl-N-(2-hydroxyethyl) ammonium chloride.

Methylated cyclodextrins: an efficient protective agent in water for zerovalent ruthenium nanoparticles and a supramolecular shuttle in alkene and arene hydrogenation reactions.

Zerovalent ruthenium(0) nanoparticles in the size range of 2.5 nm were easily prepared by chemical reduction of ruthenium salt with an excess amount of sodium borohydride and were efficiently stabilized by methylated cyclodextrins. The optimization of the catalytic system has been carried out in terms of stability and catalytic activity, considering the hydrogenation of olefinic compounds under biphasic liquid-liquid conditions.

2-Aminopyridine--a label for bridging of oligosaccharides HPLC profiling and glycoarray printing.

2-Aminopyridine derivatives of oligosaccharides (OS-AP) were printed onto microchips by two different ways. The first method is based on direct covalent insertion of OS-AP in polyacrylamide gel 3D chip. The second method is based on conversion of OS-AP into more reactive OS-aminoalditol followed by covalent printing onto NHS-activated glass slides.

Supramolecular shuttle and protective agent: a multiple role of methylated cyclodextrins in the chemoselective hydrogenation of benzene derivatives with ruthenium nanoparticles.

Efficient chemoselectivities have been obtained in the hydrogenation of benzene derivatives under biphasic liquid-liquid conditions using Ru(0) nanoparticles stabilized and controlled by the relevant choice of cavity and methylation degree of cyclodextrins.

Organic phase stabilization of rhodium nanoparticle catalyst by direct phase transfer from aqueous solution to room temperature ionic liquid based on surfactant counter anion exchange.

We describe the organic phase transfer of surfactant-stabilized rhodium nanoparticles previously synthesized in an aqueous solution of N,N-dimethyl-N-dodecyl-N-(2-hydroxyethyl)ammonium chloride (HEA12Cl); the addition of LiN(Tf)2 to the aqueous suspension of Rh-HEA12Cl transferred the hydrosol nanoparticles to an ionic liquid phase.

Development of 99mTc labelled Lipiodol: biodistribution following injection into the hepatic artery of the healthy pig.

Background: We develop a method for the radiolabelling of Lipiodol with Tc, using a lipophilic complex, [99mTc-(S2CPh)(S3Ph)2], dissolved in Lipiodol (99mTc-SSS Lipiodol).

Results: The labelling yield is high (96 +/- 0.8%), and the radiochemical purity satisfactory (92 +/- 2.

Development and biodistribution of 188Re-SSS lipiodol following injection into the hepatic artery of healthy pigs.

Although intra-arterial radiotherapy with (131)I-labelled lipiodol is a useful therapeutic approach in the treatment of hepatocellular carcinomas, various disadvantages limit its use. Here we describe the development of (188)Re-SSS lipiodol, as well as its biodistribution in the healthy pig after injection into the hepatic artery. The (188)Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with (188)Re, in cold lipiodol.