فهرست مطالب

Journal of Applied Chemical Research
Volume:6 Issue: 1, Winter 2012

  • تاریخ انتشار: 1391/03/01
  • تعداد عناوین: 8
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  • Natural Bond Orbital (NBO) Population Analysis of Iridabenzene (C5H5Ir)(PH3)3
    R. Ghiasi*, E. Ebrahimi Mokaram Pages 7-13
    The molecular structure of iridabenzene (C5H5Ir)(PH3)3 was calculated by the B3LYP density functional model using LANL2DZ basis set for Ir and 6-31G(d) for other atoms. The results from natural bond orbital (NBO) analysis have provided new insights into Ir–ligand bonding, the hybridization of atoms and the electronic structure of the title molecule. The NBO calculations show that σ(Ir-C2) bonds are formed from an sd1.18 hybrid on iridium atom π(Ir–C3) bond is formed from an sd5.21. Also, these calculations determined that strongest electron donation occurs from a lone pair orbital on the phosphorous atoms, LP(1)P to the antibonding acceptor σ*(Ir–C) orbitals.
    Keywords: Density functional theory (DFT), Metallabenzenes, Iridabenzene, Natural bond orbital (NBO)
  • Selective and Validated SpectrophotometricMethods for Determination of Acyclovir and Ganciclovirwith 2, 4 as Reagent
    T. Anil Kumar, B. M. Gurupadayya*, M.B. Rahul Reddy, M.V. Prudhviraju Pages 14-24
    New, simple and sensitive spectrophotometric methods for the determination of acyclovir and ganciclovirhave been developed. The method is based on the oxidation of 2, 4 dinitrophenyl hydrazine (2, 4 DNP) and coupling of the oxidized product with acyclovir and ganciclovirto give intensely coloredchromogen. Acyclovir and ganciclovirshowed maximum absorbance at 4 nm and 450 nm with linearity was observed in the concentration range of 20-60 μg mL-1 and 5-25 μg mL-1 respectively. The relative standard deviations of 0.016 for acyclovir and 0.014 ganciclovirwere obtained. The recoveries of acyclovir and ganciclovirtablets are in the range98.48, 99.2 respectively. The proposed method is simple, rapid, precise and convenient for the assay of acyclovir and ganciclovirin commercial tablet preparations.
    Keywords: acyclovir, ganciclovir, Oxidation, 2, 4 DNP, Spectrophotometry, Pharmaceutical formulation
  • Application of Electrochemistry to Determination of Transfer Gibbs Energies and Autoprotolysis Constants for Aqueous Mixtures of Dimethyl Sulfoxide
    A. Farjtabar* Pages 25-32
    A practical potentiometric method was applied successfully to experimental electrochemical data in order to determine the autoprotolysis constants (pKap) of water dimethyl sulfoxide mixtures containing 0-90 % of DMSO by volume at 25° C and 0.1 M ionic strength was maintained in each mixture by NaClO4 solution. The results indicated that water-DMSO mixtures are more basic media than pure water and the pKap value of media increases with addition of DMSO. The variation of pKap value over the media composition range was explained by a linear solvation energy relationship. Thus the correlations between pKap values and the Kamlet- Taft parameters were analyzed by means of multiple linear regressions. The equations obtained can be used to estimate the autoprotolysis constants in a water-DMSO solvent from the relationship between the pK ap values and the Kamlet- Taft parameters of the solvent. The literature values of transfer Gibbs free energies of H, ΔtG0(H), have been applied successfully to quantify the activity of hydroxide ion (ΔtG0(H-)) from the pure water solvent to any binary mixtures which is critical in understanding the organic reactivity in solution.
    Keywords: water-DMSO mixture solvent, autoprotolysis constant, Gibbs Energies of Transfer
  • Synthesis of Cu-TiO2Nanocomposite and Investigation of the Effectiveness of PEG, Pectin, and CMCas Additives
    B. Khodadadi, M. Sabeti*, S. Moradi, P. Aberomand Azar, S. Raeis Farshid Pages 33-41
    Recently, TiO2 has been widely used as a photocatalyst for degradation of environmental pollutants. In the present study, the advantage of metal doping onto TiO2 for enhanced photocatalitic activity has been investigated. Copper-Titanium dioxide nanocomposites were prepared by the sol gel method in the presence of Carboxy Methyl Cellulose (CMC), Pectin, and Poly Ethylene Glycol (PEG) as additives. The structures and properties of prepared samples were identified by IR spectra, Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD) methods. Furthermore, the photocatalytic activity under UV-irradiation to remove organic pollutant was investigated. The results have revealed that the photocatalytic activity of the nanocomposite in presence of additives increased. SEM pictures have shown that the particle size of Cu-TiO2 powder with additives was smaller than other samples without any additive.
    Keywords: Sol-Gel, Nanocomposite, Photocatalytic activity, Additive
  • Investigation and Determination the Binding Site of Glycyrrhizin of Liquorice to DNA
    F. Manouchehri*, S. Nafisi, M. Bonsaii, K. Abdi, M. Varavipour Pages 42-50
    Glycyrrhizin(GL), is a triterpenoid saponin found in glychyrrhiza glabra (liquorice). This compound is a frequently used and very effective drug for the treatment of various malignancies. This study was designed to examine the interactions of glycyrrhizin with calf thymus DNA in aqueous solution at physiological conditions. FTIR spectroscopic method was used to determine the ligand binding modes, using constant DNA concentration (6.25mM) and various drug/DNA (phosphate) ratios of 1/240 to 1/1. UV-Vis spectroscopic method was used to determine the binding constants and the stability of glycyrrhizin-DNA and complexes in aqueous solution, using constant DNA concentration of 5.1×10-4 M and various glycyrrhizin concentrations of 5×10-6 - 1×10-4 M. Spectroscopic evidence showed that the interaction of glycyrrhizin with DNA occurred via G, A-T and PO2 group with binding constant of KGL-DNA = 5.7×103 M-1 and DNA remains in B-DNA conformation.
    Keywords: DNA, Glycyrrhizin, liquoric, FTIR, UV-Visible spectroscopy
  • Solvent-Free Multicomponent Reactions of Dithiocarbamates, Activated Acetylenes and Isocyanides
    F. Rostami Charati *, Z. Hossaini, R. Hajinasiri Pages 51-56
    An efficient method to synthesis the 2H-pyrans using three component reactions of dithiocarbamats, activated acetylenes and isocyanides in water as the solvent is described. In these reactions, synthesis of 2H-pyrans is possible based on the one-pot reaction and without using any catalyst. The mild reaction conditions and high yields of the products exhibit synthetic advantage of these methods.
    Keywords: One, pot reactions, Dithiocarbamate, Alkyl bromides, Activated acetylenes, 2H pyrans
  • Environmental Remediation of Organic Pollutants in Synthesized and Characterized Aqueous Suspension by Photochemical Method: A Kinetic Study
    Z. Emadian Razavi, R. Fazaeli *, M. Yousefi, S. Ghasemi Pages 57-63
    Comparative study of the of azo Dyes (as a class important organic pollutants photodegradation process) in aqueous solution employing H2O2/UV and K2S2O8/UV systems in a photochemical reactor were investigated. Lead zirconate titanate [Pb (Zr0.58Ti0.42) O3] (PZT) nanocatalyst was synthesized via the sol-gel method. Then, photocatalytic properties of dopant type on PZT were determined in a UV photoreactor in the presence of different radical generators. These comparative studies showed that PZT/TiO2 and PZT/TiO2/FeCl3 have higher efficiency than the others.
    Keywords: PZT, Photodegradation, Photocatalytic, Azo dye, Nanocatalyst
  • A Combined Experimental and Theoretical Study of Optoelectronic and Structural Properties of a New Copolymer Based on Polyvinylcarbazole (PVK) and Poly (3-hexylthiophene) (PHT)
    Z. El Malki, L. Bejjit, M. Haddad, M. Hamidi, M. Bouachrine* Pages 64-86
    In this paper we report on a combination of experimental and theoretical study of a new copolymer based on carbazole and methylthiophene (Cbz-Mth), in their neutral and oxidized states. We discuss the influence of chain length on conformational and optoelectronic properties with the DFT method. Conformational analysis shows that there are no big changes in the structural parameters of neutral oligomers. In the doped form, the oligomer structures become nearly planar and show a quinoidal character. The results obtained for (Cbz-Mth)3 from the neutral state, are close to experimental values.
    Keywords: (Cbz-Mth) oligomers, DFT, Conformational analysis, Optoelectronic properties, Polaronic, bipolaronic forms