Search Results (2)

A series of composites containing nanoparticles of NiO (from 1 to 10% by weight per Ni), deposited on NORIT charcoal, was prepared by the decomposition of the Ni⁰ complex Ni(cod)₂ (cod = cis,cis-1,5-cyclooctadiene). Ni content in the composites was set by loading the appropriate quantities of the Ni(cod)₂ precursor. The catalytic activity of the composites was associated with the in situ generation of active sites due to a reduction in NiO, hence the composites could be stored in air without a loss in their catalytic performance. The composites were analyzed by powder XRD, TEM, XPS, and adsorption methods. The hydrogenation of quinoline was used as a reference reaction for studies of the influence of temperature, P(H₂), catalyst loading on the product yield, and for the selection of the composite possessing the highest performance. It was found that 3% Ni loading was the most optimal. This composite was used as an efficient catalyst for the hydrogenation of compounds with ethylene and acetylene bonds, nitro- and keto- groups as well as a series of substituted quinolines and analogs. The studied composites can be proposed as air-stable and efficient catalysts for the hydrogenation of a wide range of organic compounds. Full article

In an effort to develop new ruthenium(II) complexes, this work describes the design, synthesis and characterization of a ruthenium(II) functionalized phenanthroline complex with extended π-conjugation. The ligand were L₁ (4,7-bis(2,3-dimethylacrylic acid)-1,10-phenanthroline), synthesized by a direct aromatic substitution reaction, and L₂ (4,7-bis(trianthracenyl-2,3-dimethylacrylic acid)-1,10-phenanthroline), which was synthesized by the dehalogenation of halogenated aromatic compounds using a zero-valent palladium cross-catalyzed reaction in the absence of magnesium-diene complexes and/or cyclooctadienyl nickel (0) catalysts to generate a new carbon-carbon bond (C-C bond) polymerized hydrocarbon units. The ruthenium complex [RuL₁L₂(NCS)₂] showed improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients), luminescence and interesting electrochemical properties. Cyclic and square wave voltammetry revealed five major redox processes. The number of electron(s) transferred by the ruthenium complex was determined by chronocoulometry in each case. The results show that processes I, II and III are multi-electron transfer reactions while processes IV and V involved one-electron transfer reaction. The photophysical property of the complex makes it a promising candidate in the design of chemosensors and photosensitizers, while its redox-active nature makes the complex a potential mediator of electron transfer in photochemical processes. Full article