نشریه شیمی کاربردی روز
پیاپی 10 (بهار 1388)

We have developed a convenient and efficient method for coupling of aryl iodides and bromides with terminal alkynes. The protocol uses CuI as catalyst, 1, 10-phenanthroline as ligand, KF/Al2O3 as base and toluene as solvent. The method is suitable for the synthesis of functionalized aryl-alkynes.

In this paper, the effect of different reaction conditions on the grafting of acrylamide (AM) onto kappa-carrageenan (kC) using potassium persulfate (KPS) initiator has been studied by determining the grafting parameters. The reactions were carried out under argon atmosphere in a homogenous aqueous medium. After removal of the homopolymer, the graft copolymer was characterized by FTIR spectroscopy. A plausible mechanism of grafting has also been suggested. It was observed that with increasing AM, kC, and KPS concentrations as well as reaction time and temperature the grafting parameters were increased, but further increase of reaction conditions disfavored these parameters.

1-(2-Pyridylazo)-2-naphthol (PAN) has been used for the simultaneous determination of nickel and cobalt at trace levels. PAN complexes of nickel and cobalt in the pH 1.89 form red and green colored complexes, respectively which are soluble in aqueous Tween 80 micellar media. Under optimum conditions, calibration graphs for simultaneous determination by first derivative spectrophotometry were obtained. Zero crossing first derivative spectrophotometry at 641 and 580 nm was used for the simultaneous determination. The method is able to determine cobalt to nickel ratio 15:1 to 1:6 (Wt/Wt), accurately. Accuracy and reproducibility of the determination method on the known various amounts of cobalt and nickel in their binary mixtures were tested. Effects of diverse ions on the determination of cobalt and nickel to investigate selectivity of the method were also studied. The recommended procedure was applied to various nickel-cobalt alloys.

The first catalytic application of p-TsCl for efficient acetylation of various types of alcohols and phenols with acetic anhydride in both solution and solvent-free conditions is reported. Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-TsCl under solvent-free condition. The reactions were carried out in short reaction time and in good to excellent yields at room temperature.

A very sensitive, simple and selective spectrophotometric method for simultaneous determination of phosphate and silicate based on formation of phospho- and silicomolybdenum blue complexes in the presence of ascorbic acid is described. Although the complexes of phosphate and silicate with reagent show a spectral overlap, they have been simultaneously determined by partial least squares (PLS). The linear range was 0.01-2.80 μg ml-1 for phosphate and 0.02-3.00 μg ml-1 for silicate. Interference effects of common anions and cations were studied and the proposed method was also applied satisfactorily to the determination of phosphate and silicate in synthetic detergents.

This paper introduces a new class of bidentate ligands as antidote drugs. By semi-empirical AM1 method calculations, we showed that natural amino acids could be used as theoretically good antidote drugs. To reach this goal, we have calculated the stability energies of glycine, alanine, valine, leucine, isoleucine, serine and threonine and their complexes with Zn2+ as indicated.

In the present work, a simple and relatively fast spectrophotometric method was developed for the determination of sodium dodecylsulfate in wastewater based on the formation of an ion-pair, surfactant-Safranin-O (SDS-SO). Parameters such as type and concentration of counter ion, shaking time, type of organic solvents, type of inorganic acid, and pH of aqueous phase, which affect extraction efficiency, were studied and optimized. Under the optimal experiment conditions, the method exhibited a wide linear range (0.3–17.0 μM) with detection limit of 0.2 μM. Analytical accuracy and precisions, determined from replicate (n=6) analysis of spiked laboratory standards, were in the range of 91 to 106 % and lower than 1.6 %, respectively.