Cross-Coupling Versus Homo-Coupling Reactions with Benzyl Bromide,Magnesium and Chlorotrimethylsilane

The selective synthesis of benzyltrimethylsilane from PhCH₂Br, Mg and Me₃SiCl requires a low reaction temperature.     

Fast Convergence of Dynamical ADMM via Time Scaling of Damped Inertial Dynamics

Journal of Optimization Theory and Applications - In this paper, we propose in a Hilbertian setting a second-order time-continuous dynamic system with fast convergence guarantees to solve...     

Ultrasound-promoted solvent-free aza-Michael addition of p-toluenesulfonamide to fumaric esters by potassium carbonate: Synthesis of p-toluenesulfonamide derivatives

An efficient, mild, inexpensive and eco-friendly protocol for the synthesis of p-toluenesulfonamide derivatives by aza-Michael addition reaction of p-toluenesulfonamide to fumaric esters using potassium carbonate under ultrasound irradiation was developed. This method is simple, convenient and the desired compounds are produced in good to excellent yield. The bulkiness of alkoxy group (–OR) of fumaric esters did not affect significantly on the yields and reaction times. This reaction worked well on linear and nonlinear alkyl fumarates. The reaction, surprisingly, was not successful on methyl fumarate. In this case methyl fumarate has been hydrolyzed to fumaric acid under reaction conditions.     

Applications of Non-precious Transition Metal Oxide Nanoparticles in Electrochemistry

Non-precious transition metal oxide nanomaterials offer numerous opportunities for various cost-effective electrochemical applications. This review article features the design and advancement of such nanomaterials with unique features applied for the fabrication of electrochemical devices. Also, it discusses various new syntheses of transition metal oxide nanoparticles (TMO NPs) via multiple chemicophysical and biological procedures. Further, the novel appliances of the TMO NPs with varying sizes and morphologies are appraised. The advantages and challenges of a number of investigations on the TMO NPs towards electrochemical applications are addressed with their standpoint of cost-effectiveness, applicability, and the efficiency of the introduced nanostructures for the industrial applications.     

Heat‐Induced Radiolabeling of Nanoparticles for Monocyte Tracking by PET

Heat‐induced radiolabeling (HIR) yielded ⁸⁹Zr‐Feraheme (FH) nanoparticles (NPs) that were used to determine NP pharmacokinetics (PK) by positron emission tomography (PET). Standard uptake values indicated a fast hepatic uptake that corresponded to blood clearance, and a second, slow uptake process by lymph nodes and spleen. By cytometry, NPs were internalized by circulating monocytes and monocytes in vitro. Using an IV injection of HIR ⁸⁹Zr‐FH (rather than in vitro cell labeling), PET/PK provided a view of monocyte trafficking, a key component of the immune response.     

Optical properties of electron beam- and UV-cured polypropyleneglycoldiacrylate/liquid crystal E7 systems

This contribution focuses on a detailed investigation of the relationship between the method of polymerisation/cross-linking, such as slow and rapid UV radiation, and high voltage accelerated electron beam (EB), and the obtained physical properties including phase diagrams, polymerisation and phase separation kinetics, morphologies and electro-optic responses of polypropyleneglycoldiacrylate (PPGDA) monomers, in the presence of the nematic liquid crystal E7. The longer the spacing between double bonds, the more rapid was the photopolymerisation under both UV systems; however, the reverse was proved under EB. More homogenous and regular morphologies were obtained under EB curing.

The electro-optical responses of various polymer dispersed liquid crystals (PDLCs) systems exhibited remarkable differences between the UV-cured samples and those cured by the EB technique. It was found that the threshold and saturation voltages considerably increased in the case of the UV-cured systems. Other results involving the contrast ratio, which is higher for EB-cured systems, confirm their higher quality, although the rapid photopolymerisation UV source was employed, which slightly improved the electro-optical responses. Moreover, EB curing leads to high enough conversions without a photoinitiator, which may act as an impurity that might have a strong impact on the electro-optical performance of the obtained PDLCs.     

Palladium catalyzed oxidation of allylsilanes with U.V. light and molecular oxygen (1)

Photolysis of oxygenated acetone solutions of allylsilanes containing small amounts of palladium led to α,β-ethylenic alcohols, aldehydes or ketones. Efficient regiospecific oxidation can be observed when the allylsilane was substituted by an arylsulphonyl group.     

A rapid HPLC assay for the simultaneous determination of propafenone and its major metabolites in human serum.

A rapid and specific HPLC method has been developed and validated for the simultaneous determination of propafenone, an antiarrhythmic agent, and its major metabolites in human serum. The sample preparation was a simple deproteinization with a mixture of ZnSO4 and methanol, yielding almost 100% recoveries of three compounds. Separation was developed on a reverse-phase tracer excel C18 column (25 x 0.46 cm i.d., 5 microm), using an acetonitrile-phosphate buffer gradient at a flow rate of 1.7 ml min(-1), and UV detection of 210 nm. The calibration curves were linear (r2 > 0.999) in the concentration range of 10 - 750 ng ml(-1). The lower limit of quantification was 10 ng ml(-1) for all of the compounds studied. The within and between day precisions in the measurement of QC samples at four tested concentrations were in the range of 1.4 - 8.1% and 4.2 - 11.5% RSD, respectively. The developed procedure was applied to assess the pharmacokinetics of propafenone and its major metabolites following administration of a single 300 mg oral dose of propafenone hydrochloride to three healthy male volunteers.     

A competitive polarographic study of complexation of ammonium,anilinium, hydrazinium and pyridinium ions with some macrocyclic ligands in binary ethanol-water mixtures using a Pb(II)/Pb(Hg) couple as an electrochemical probe

The formation of ammonium, anilinium, hydrazinium and pyridinium ion complexes with the crown ethers 18-crown-6 (18C6) and 1,10-diaza-18-crown-6 (C22) and the cryptand C222 in different binary ethanol-water mixtures has been studied by a competitive polarographic method using a Pb²⁺/Pb(Hg) couple as a sensitive electro-chemical probe. Lead ion was found to form very stable complexes with the ligands used, in all solvent mixtures studied; Pb²⁺–C222 cryptate revealed a pronounced cryptate effect compared to the corresponding complexes with the monocyclic crown ethers used. In all solvent mixtures studied, the stability of the resulting 11 complexes between the protonated amines and macrocyclic ligands used vary in the order C22>C222>18C6. The observed selectivity order of each macrocyclic ligand used for different protonated amines is discussed based on the chemical and structural features of the host-guest partners in solution. In all cases studied there is an inverse linear relationship between the complex formation constants and the mole fraction of water in the mixed solvent.