Half-sandwich Ni(II) complexes bearing enantiopure bidentate NHC-carboxylate ligands: efficient catalysts for the hydrosilylative reduction of acetophenones.

Chiral nickel complexes containing NHC-carboxylate chelate ligands derived from the ()-isomeric form of amino acids have been synthesised from the corresponding imidazolium salt and nickelocene. The presence of the carboxylate on the -side arm of the heterocycle results in the competing formation of mixtures of mono- and bis-NHC complexes (, [Ni(η-Cp)(κ-,-NHC)] and [Ni(κ-,-NHC)]), both of which retain the ()-configuration of the stereogenic center and which can be separated by chromatography. Both the 18e and 16e complexes are found to be very stable and cannot be interconverted.

Synthesis and Characterization of Graphene Oxide Derivatives via Functionalization Reaction with Hexamethylene Diisocyanate.

Graphene oxide (GO), the oxidized form of graphene, shows unique properties including high mechanical strength, optical transparency, amphiphilicity and surface functionalization capability that make it attractive in fields ranging from medicine to optoelectronic devices and solar cells. However, its insolubility in non-polar and polar aprotic solvents hinders some applications. To solve this issue, novel functionalization strategies are pursued.

Synthesis and behavior of novel sulfonated water-soluble N-heterocyclic carbene (η(4)-diene) platinum(0) complexes.

A series of water-soluble (NHC)Pt(0)(dvtms) and (NHC)Pt(0)(AE) complexes containing different sulfonated NHC ligands (dvtms = divinyltetramethyldisiloxane and AE = diallyl ether) are reported. The dvtms compounds have been found to be quite robust and to display some conformational rigidity, whereas their AE counterparts are less stable and more flexible. The catalytic evaluation of these complexes in the hydrosilylation of alkynes in water revealed no benefits in favor of the complexes containing the more labile spectator diene (AE), and a fairly regular catalytic behavior for all complexes that restricts the location of the sulfonate group to the proximity of the metal site.

Multipurpose ultra and superhydrophobic surfaces based on oligodimethylsiloxane-modified nanosilica.

Nonfluorinated hydrophobic surfaces are of interest for reduced cost, toxicity, and environmental problems. Searching for such surfaces together with versatile processing, A200 silica nanoparticles are modified with an oligodimethylsiloxane and used by themselves or with a polymer matrix. The goal of the surface modification is controlled aggregate size and stable suspensions.

New chiral ligands bearing two N-heterocyclic carbene moieties at a dioxolane backbone. Gold, palladium and rhodium complexes as enantioselective catalysts.

Biscarbene ligands with two imidazolin-2-ylidene moieties at a chiral dioxolane backbone were used as ligands for gold, rhodium and palladium complexes. All new complexes showed varying degrees of enantioselectivity toward hydrogenation of prochiral alkenes with ees up to 95%.

Nanotubular self-assembly of n-dodecylamine-TEOS-water-acetonitrile mixtures.

We report for the first time the observation of self-assembled nanotubular structures from n-dodecylamine-TEOS-water-ACN mixtures; the presence of these nanotubular domains was found to be strongly influenced by the generation of in situ metal nanoparticles and the presence of halide anions.

Microwave efficient S-arylation of thiols with aryl iodides using supported metal nanoparticles.

An efficient and green microwave-assisted heterogeneous S-arylation protocol, reported for the first time, provided excellent coupling conversions and selectivities in minutes of reaction using Fe (homocoupling) and Cu (cross-coupling) supported metal nanoparticles.

Synthesis of bifunctional Au-Sn organic-inorganic catalysts for acid-free hydroamination reactions.

Gold(III) complexes heterogenized on the surface of a Sn-containing MCM-41 are efficient recyclable catalysts for hydroamination reactions, without requiring any acid promoters.

Enantioselective hydrogenation of alkenes and imines by a gold catalyst.

A new neutral dimeric gold(I) complex bearing the 1,2-bis[(2R,5R)-2,5-dimethylphospholanebenzene] [(R,R)-Me-Duphos] ligand has been synthesized which catalyzes the asymmetric hydrogenation of alkenes and imines under mild reaction conditions.