Journal of Physical Chemistry & Electrochemistry
Volume:2 Issue: 1, 2013

The adducts produced in the reaction between trialkyl phosphites and acetylenic esters were trapped by hydantoins to produce highly functionalized dialkyl 2-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl) succinate in good yields.

The interactions of β-lactoglobulin AB in the presence of cationic surfactants such as Cetyltrimethylammonium bromide and Cetyltrimethylammonium p-Toluenesulfonate have been investigated using a variety of experimental techniques such as conductivity, UV-Vis spectrophotometry and fluorimetry. The conductivity of surfactants aqueous solutions with β-lactoglobulin shows that the cmc of cationic surfactants decreases with increasing of counterion size. The results of UV-Vis and fluorescence studies show a red shift in wavelength and an increase in absorbance and intensity of the emission maximum of protein during the interactions of surfactants with β-lactoglobulin. The results of UV-Vis also show two distinct conformational changes at pHs 6.7 and 8.0 and the cooperative character of binding at pH 2.0. The results of fluorescence studies show that the binding strength of β-lactoglobulin / surfactant complex decreases with increasing of the pH.

The complexation reactions between Cu2+, Pd2+ and Ni2+ metal ions with promethazine (PM) in water or DMF were studied by the spectrophotometric methods at [(15, 25,35 and 45±0.1) °C]. The complexation process was optimized in terms of pH, temperature and contact time. The stoichiometry of the complex was found to be 1:1 (metal ion/ligand). The formation constants of the resulting complexes were determined from computer fitting absorbance-mole ratio data. The values of the thermodynamic parameters for complexation reactions were obtained from the temperature dependence of the stability constants. The proposed method was successfully applied for the determination of PM in their dosage forms.

In this work, the study of various substituted Kaempferol derivatives is presented. The bond dissociation energies (BDE) have been calculated using B3LYP level and different basis sets in gas-phase. Calculated results show that the BDE values of substituted Kaempferol range from about 77 to100 kcal/mol, demonstrating that Kaempferol is an effective chain-breaking antioxidant that prevents lipid peroxidation. Also we can seen, Cl, OH, CN, NH2 and CH3 groups in C3′ position, CH3, OH and NH2 groups in C5′ position and NH2 and CN groups in C6′ position destabilize the parent Kaempferol molecule and stabilize the radical; hence, it decreases the O-H BDE.

An efficient three-component reaction of dialkyl acetylendicarboxylates and 2-Pyrrolidin in the presence of triphenylphosphine produces dialkyl 2-(2-Pyrrolidin-N-yl)-3-(triphenylphosphanylidene)succinate. These phosphoranes undergo mild intramolecular Wittig reaction to produce dialkyl (E)-2-(4,5-dihydro-3H-pyrrol-2-yl)fumarate in excellent yields.

The reaction of CH3O2 radicals with acetaldehyde on the solid surface of NH4NO3 has been studied in a flow capillary reactor at low pressure and room temperature. The experiments were performed using EPR spectrometer combined with the kinetic method of radicals freezing. Peroxy radicals revealed an oscillation complex behavior during the process regarding to the phenomenon of radicals multiplication. The kinetic peculiarities of process depend intensively on the concentration and the nature of organic compound and aerosol surface. The increase of mass percentage of oxygen of the aerosol substances can be responsible for increasing the amplitude of radicals oscillation behavior.

This paper presents a methodology, based on the taguchi parameter design approach, for the optimization of process parameters for bismuth recovery from aqueous solutions. The process parameters considered are [Bi3+], [NaCl], temperature, and cathodic current density. In addition, cell voltage and current efficiency as two responses have been considered. An orthogonal array L9, the signal-to-noise (S/N) ratio, and the analysis of variance were used to analyze the effect of selected process parameters and their levels. From a metallurgical point of view, the separation and recovery of bismuth from a bismuth glance concentrate through leaching, purification and electrowining of chloride solutions were carried out. The optimum conditions for the selected parameter values were found as [Bi3+] (75 g/L), [NaCl] (25 g/L), temperature (65°C) and current density (100 A/m2). Finally, a mathematical model has been proposed and the results of a confirmatory run are reported to verify the results, which indicate that this methodology is more efficient in optimizing the process parameters.

An agricultural waste i.e. rice husk has been used as a cheap adsorbent for the removal ofleadas a harmful heavy metal from contaminated water via adsorption. The adsorption capacity of rice husk was calculated by equilibrium models. The results showed that the adsorption process has the best accordance with Langmuir model. The kinetics of the adsorption was also investigated and obtained that the experimental data has the best fit with pseudo-second kinetic model. In this study, the effect of the adsorbent amount as well aspH value on the results was also investigated.