فهرست مطالب

Chemical Research - Volume:5 Issue: 2, Spring 2012

Journal of the Iranian Chemical Research
Volume:5 Issue: 2, Spring 2012

  • تاریخ انتشار: 1391/03/30
  • تعداد عناوین: 8
|
  • Amir H. M. Sarrafi *, Elahe Konoz, Kobra Shabani Pages 55-63
    A sensitive and simple method for simultaneous preconcentration of trace heavy metal ions in some cereal and vegetable samples has been reported. The method is based on the adsorption of Cu2, Fe3, Zn2 and Pb2 on 2-(2-nitro-phenylazo)-naphthalen-1-ol (NPN) loaded on activated carbon (AC). The adsorbed metals on activated carbon were eluted using 3 ml 4 mol L−1 nitric acid. The influences of the analytical parameters including pH, flow rate of sample and eluent, type and concentration of eluent, amount of adsorbent and sample volume were investigated. The effects of matrix ions on the recoveries of analyte ions were also investigated. The recoveries of analytes were generally higher than 95%. The detection limits for Cu2, Fe3, Zn2 and Pb2 were 0.17 μg L-1 , 0.16 μg L-1 ,0.11 μg L-1 and 0.12 μg L-1 respectively.
    Keywords: Solid, phase extraction, FAAS, trace metal enrichment, Activated Carbon, 2, (2, nitro, phenylazo), naphthalen, 1, ol
  • Majid Ghashang *, Mohammad Reza Mohammad Shafiee, Batool Hojati Najafabadi Pages 65-71
    A highly efficient and environmentally friendly synthesis of various 1,5-diaryl-3-(arylamino)-1H-pyrrol- 2(5H)-ones catalyzed by 1-methylpiperidinium hydrogen sulfate via one-pot cyclo-condensation reaction of aldehydes, amines and ethyl 2-oxopropanoate under ambient conditions has been explored. The present methodology offers several advantages such as good yields, simple procedure, shorter reaction times and milder conditions and the products were purified without resorting to chromatography.
    Keywords: 1, 5, diaryl, 3, (arylamino), 1H, pyrrol, 2(5H), one, ?, lactam, Ionic liquid, 1, methylpiperidinium hydrogen sulfate
  • Saeed Jameh-Bozorghi *, Zahra Javanshir, Fatemeh Naseri, Maryam Darvishpoor Pages 73-84
    Structural properties, energies behavior and NBO analysis was performed for1-5 prototrophic shift endinel boran where substitutions like H, CH3 and CF3 that were placed on Benzene were investigated by using DFT-B3LYP/6-311** level of theory. The Results show that, -BH2 shift doesn’t take place and a kind of [1,3] shift for borotrophic occured. In prototrophic shift, however, [1,5] transition easily happened. The Results of calculations using B3LYP, HF and MP2 [basic seyies 6-311**] show that Ea for CF3 substitutionis is lower than H substitution; also, this amount of activation energy for CH3 was lower than CF3. But for prototrophic shift, activation energy changes, as will be shown in the following CF3, H and CH3 tables. Finally, prototrophic shift activation energy in proportion to that of borotrophic shift is higher. Lower amount of activation energy in bortorphic shift show that rotation of bore on the cycle can happen in the ambient temperature.
    Keywords: DFT calculation, Borotropic shift, Prototropic shift, Indol
  • Ali Ainirad * Pages 85-91
    In this work, Ce0.75Gd0.1Ca0.15O1.8 nanopowders are successfully synthesized by a Glycine-nitrate combustion process under the microwave irradiation. Then calcination was carried out at 700 °C. Calcined powders identified by room temperature X-ray diffraction were single phase and had a crystallite size between 16 to 24 nm (based on Schererr formula). Scanning electron microscopy (SEM) was employed to characterize the morphology of powder. We also studied the effect of fuel to nitrate ratio on the amount of released energy and on the crystallite size and compositional homogeneity of the resulting powders. Finally electrical properties of obtained powder were studied.
    Keywords: Solid Oxide Fuel Cell, Doped ceria, Microwave, Combustion Synthesis
  • Nina Alizadeh *, Mojtaba Shamsipur Pages 93-101
    The formation of charge-transfer complexation between dibenzo-15-crown-5 (DB15C5) and benzo-12- crown-4 (B12C4) (Donor) and iodine is investigated spectrophotometrically in three chlorinated solvents, chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solution at 25°C. The change in polarity of the solvent also doesn’t affect the stoichiometry of the complexes. Values of formation constants reflect the order of ionization potentials of the donors. The observed time dependence of the charge-transfer band and subsequent formation of I3- ion are related to the slow formation of the initially formed 1:1 Donor.I2 outer complex to an inner electron donor-acceptor (EDAr) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion, as follows:Donor I2 → Donor. I2 (outer complex), fast
    Donor.I2 (outer complex) → (Donor. I)I- (inner complex), slow
    (Donor . I)I- (inner complex) I2 → (Donor .I)I3-, fast
    The pseudo-first-order rate constants for the transformation process were evaluated in different solvent systems. The stability constants of the resulting EDAr complexes were also evaluated and the solvent effect on their stability are discussed. The resulting complexes were isolated and characterized by FTIR and 1HNMR spectroscopy.
    Keywords: Charge, transfer complex, Iodine, Dibenzo, 15, crown, 5, benzo, 12, crown, 4, Kinetics, Formation constant, spectrophotometry, FTIR, 1H, NMR
  • Nader Saemian *, Gholamhossein Shirvani, Mohsen Javaheri Pages 103-107
    N-(7-chloro-1-methyl-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)thiophene-2 carboxamide- [14C-carboxy] was prepared as part of a 6-step sequence from thiophene-2-carbonitrile -[cyano-14C] as a key synthetic intermediate which has been synthesized from 2-iodothiophene and zinc [14C]-cyanide in the presence of tetrakis (triphenylphosphine) palladium.
    Keywords: thiophene, 2, carbonitrile, Cholecystokinin antagonist, Carbon, 14, benzodiazepin
  • Beena Bhaskaran *, Manoj Sadanandan Pages 109-118
    Nanoparticles of zirconium(IV) tungstate are prepared by chemical co-precipitation method. The characterizations have been carried out by TG/DTA, DSC, AFM, XRD, FTIR and UV-Vis spectrum. PL spectrum shows two emission bands at 350 nm and at 477 nm. The effects of frequency on the dielectric behavior and ac electrical conductivity have been studied. The dielectric constant is found to be 119.43 at 1MHz. The ac conductivity is 7.29x10-8S/cm.
    Keywords: Zirconiun(IV)tungstate, AFM, Optical band gap, ac conductivity, dielectric constant
  • Sunakar Panda *, Jagat Krushna Tripathy Pages 119-128
    Inclusion complexes of 2-[Arylidenamino]-1,3,4-thiadiazino[6,5b]indoles have been prepared with β- cyclodextrin so as to increase the solubility of these compounds in polar medium which may increase their bioaccessibility. The formation of inclusion complexes is known from the study of changes in physical and spectral properties of the compounds. The stability of the inclusion complexes has been studied by the determination of the thermodynamic parameters like change in free energy, change in enthalpy and change in entropy. Finally compounds and their inclusion complexes are screened for antibacterial and antioxidant activities. It is found that both antibacterial and antioxidant activity of the compounds increase significantly after the inclusion complex formation. In addition, the presence of activating groups on arylidene unit further favours inclusion complex formation and also stabilizes the same.
    Keywords: Substituted indole, ? Cyclodextrin, Inclusion complex, Antimicrobial activity, Antioxidant activity