نشریه شیمی کاربردی روز
پیاپی 22 (بهار 1391)

In this approach، hierarchically structured cobalthas been applied as modifier for determination of acetaminophen. These nanostructures have been synthesized using a chemical reduction method. They were characterized by scanning electron microscopy and cyclic voltammetry. The modified electrode exhibits an electrocatalytic activity toward oxidation of acetaminophen. The effect of pH and scan rate has been studied. Differential pulse voltammetry has been used for quantitative determination af acetaminophen. A dynamic linear range 1×10-3Mto 1×10-6M with a limit of detection 5× 10-7 M obtained. The modified electrode has been successfully applied for determination of acetaminophen in synthetic serum and commercial tablets.

Heavy metal ions، especially mercury، lead، and copper are found in the waste water used in the chemical industry، particularly in the nuclear industry، dye and metallurgy. These pollutants affect the health of humans and other organisms، so the removal of the pollutants from the wastewater is very important. In this paper dithiocarbamate coated iron oxide nanoparticles (DTC-MNP) were synthesis and were used for the separation of heavy metal ions from contaminated water. The adsorption performances of DTC-MNP towards heavy metals such as Cu (II) and Hg (II) were systematically investigated based upon which the adsorption mechanisms were deeply exploited. The adsorption of Cu (II) and Hg (II) onto DTC-MNP was strongly dependent on pH of the system. The results showed that the dithiocarbamate coated nanomagnets can remove heavy metals such as copper and mercury particles up to 200 ppm.

The present work describes the synthesis، characterization and the investigation of electrochemical and catalytic performance of a series of new N2O2type oxidovanadium (IV) Schiff base complexes. The Schiff base ligands had salophen type structure and were derived from the condensation of 4-methyl or 4- nitro-1،2-phenylenediamine with salicylaldehyde. The catalytic ability of the complexes was studied in the process of epoxidation of cyclooctene with tert-butylhydroperoxide (TBHP). Several factors affecting this catalytic ability was optimized such as solvent type، catalyst amount، substrate to oxidant ratio، and reaction time. Electrochemical studies revealed that in the presence of electron withdrawing groups، the VIV/VV redox potentials shifted to more positive values. Besides، the catalytic performance of the complexes was increased by this increase.

Propanil is one of the most effective rice herbicide which has been produced in good yield and easy method from 1،2-dichlorobenzene with nitration to 3،4-dichloronitrobenzene and then reductive amidation with iron powder in propanoic acid. Ease of operation، less reaction steps than previous approaches، lack of rugged process such as hydrogenation and using of inexpensive reactants are some performance of presented method.

In this work we describe chemical precipitation method as a simple and fast method for synthesis of CdO nanoparticles. Synthesis of CdO nanoparticle optimize in laboratory condition. Effective factor in nanoparticle size such as ratio between NaOH and Cd (NO3) 2 concentration and calcinations temperature optimized. Properties of nanoparticles investigate using electrochemical impedance spectroscopy، TEM and XRD methods. Results confirm presence of CdO nanoparticles. Results show that in the ration of 0. 25 to 0. 5 of Cd (NO3) 2 and NaOH the diameter of CdO nanopartice are 17. 5 nm. The 400 0C is best calcinations condition for synthesis of CdO nanoparticles.

In this study with a unique method، two samples of Ni-Pd/Al2O3 nanocatalyst were synthesized by new type of sol-gel method and with different aluminum precursors. In one case ammonia solution was added drop by drop to a well-stirred aqueous solution of aluminum nitrate to precipitate hydroxide in the pH=10، after gelation for 2 hours، nickel and palladium nitrate salts solution added to gel in aging step، after 6 hours catalyst (C1) precursor was prepared. In other case aluminum isopropoxide was refluxed at 70°C and then the suspension kept at 90°C/2 h for remove of alcohol، remains steps for preparation of catalyst (C2) precursor، were at the same of above. The gels washed with deionized water، and dried at 120°C then calcinated at 650 °C/5 h in air to produced porous catalysts (C1and C2). The obtained catalysts characterized by SEM، XRF، XRD، BET and PSA techniques. These powders showed BET surface area، 196 and 226 m2/g and PSA data 300 to 700nm for C1and C2 respectively.

In this work the synthesis، characterization and the crystal structure of a trinuclear complex cobalt containing the salen type ligand and the 4-acetylpyridine ligand has been discussed. This complex is a mixed valence، trinuclear species with the oxidation states of the metal centers assigned as Co (III) – Co (II) –Co (III). The terminal Co (III) centers are equivalent with the central Co (II) lying on the inversion center of the complex. All phenolate groups bridge to the central Co (III). The coordination sphere about each metalcenter in the trinuclear complex is completed by two acetate groupsand 4-acetylpyridine ligands.

In this research، zeolite NaY molecular sieve was prepared by a hydrothermal method. Then، silver ions were replaced in the zeolite NaY with silver nitrate (AgNO3) solution viausingion exchange (IE) method for the preparation of zeolite AgY. In the next step، the Manganese dioxide (MnO2) nanoparticles (9. 3 and 15. 8 wt %) as guest were deposited in the zeolite AgY (as host) structure with Mn (NO3) 2 aqueous and KMnO4 solutions via confined space synthesis (CSS) method. Synthesized samples were studied and characterized via SEM/EDAX، XRD and FTIR techniques. The desulfurizationand removalreactions of sulfurous compounds ofchloroethyl ethyl sulfide (CEES)، chloroethyl phenyl sulfide (CEPS) and organo-phosphurouscompounds ofdemeton and dimethyl methyl phosphonate (DMMP) have been investigated by 15. 8 wt% Nano MnO2/Zeolite AgY composite via the influences of various parameters such as solvent and time by using gas chromatography (GC) and 31PNMR. Then، products of the elimination and destruction reactions were identificated via gas chromatography-mass spectrometry (GC-MS). These products have less toxic to compare sulfurous and organo-phosphurous compounds under reaction.