Classical chemical sciences
A halogen-free ionic liquid, tetraoctylammonium dodecylbenzene sulfonate was used to extract Cu2+, Pb2+, Cd2+, and Hg2+ from their aqueous solutions by using dithizone as chelating agent. Inductively coupled plasma-mass spectrometry (ICP-MS) was applied, at different pH-values, to simultaneously measure the metal content in the aqueous phase, both before and after extraction. At the optimum pH value, extraction of the four metal cations from pure solution and marine water samples was successfully accomplished and their concentrations were simultaneously determined.
Keywords: Halogen-free ionic liquid; Heavy metals, Solvent extraction, Inductively coupled plasma
The complexation of urea (U) with mercury(II) and nickel(II) ions at room temperatures and 60 oC has been studied by many methods namely elemental analysis, magnetic susceptibility, conductivity measurements, infrared and thermal analysis (TG/DTG), scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), and x-ray powder diffraction (XRD) method. The physical and spectral data were well explained in terms of the formation of HgCl2.4U.2H2O (1) and Ni(NO3)2.2U.2H2O (2) at room temperature, on one hand, and HgCl2.2U.2H2O (3) and on the other hand Ni(NO3)2.2U.H2O (4) at 60 oC. On the basis of the infrared spectral data and the values of stretching vibrational bands of both –C=O and –NH2 groups, the complexation of metal ions toward urea was distinguished. The enhancement of the microbial treatments against bacteria (Escherichia Coli, Staphylococcus Aureus, Bacillus subtilis and Pseudomonas aeruginosa) and fungi (Aspergillus Flavus and Candida Albicans) was assessed and a remarkable efficiency was recorded for complexes (1) and (2).
Keywords: Urea, Hg(II) , Ni(II), Biological activity, Spectroscopic studies, Thermal analysis
The complex of [Co(m-hba)2(Dena)2(H2O)2], diaquabis(m-hydroxybenzoato-O)bis(N,N-diethylnicotinamide-N)Cobalt(II), C34H42CoN4O10, referred to in the title, has been synthesized and explained as structural by using elemental analysis, FT-IR spectra, UVVis reflectance, magnetic measurements, thermal analysis, mass spectra and X-ray diffraction methods. The analysis results showed that the unit cell of the complex includes one molecule of CoII-cation, two molecules of m-hydroxybenzoate, two molecules of N,Ndiethylnicotinamide ligands and two molecules of aqua ligands. The compound crystallizes in the triclinic space group P-1 with the following unit-cell parameters: a=8.7288(3)Å, b=14.2213(4)Å, c=15.4307(5), =108.270(2)º, =92.473(3)º,=102.549(5)º and Z=2. The compound crystallizes in the space group P-1 with Z’=1. The asymmetric unit of the complex C34H42CoN4O10 contains two crystallographically independent molecules. Each CoII ion located at a centre of symmetry and is coordinated by two O atoms from two equivalent carboxylate groups, two O atoms from aqua ligands, and two pyridyl N atoms. It has strong paramagnetic properties.
Keywords: mixed ligand complexes, Co(II) complex, N,N-diethylnicotinamide, m-hydroxybenzoate, thermal decomposition, X-ray structure, mass pattern
Here we extend a set of earlier articles that dealt with time-dependent irreversible processes across a thin boundary separating a system from its surroundings. The entropy change for irreversible transfers of heat, work, and matter in this compound system is examined for a one component condensed phase for which temperature, pressure, and mole numbers are the control variables. The required fundamental relations are collected and evaluated to generate an expression for the entropy change in terms of experimentally determinable variables. Contributions to the entropy change from heat exchange, work performance, and material transfer are evaluated for two distinct timedependent paths. While contributions from each element differ for the two cases, the sum of all three elements remains identical for both time variations, as is consistent with entropy being a function of state. The net entropy change upon irreversibly cycling is also assessed.
Keywords: Irreversible Processes, Transfer Across Boundaries, Entropy of Irreversible Transfers, Quasistatic Irreversible Processes
Five ion-associates of the drug sildenafil citrate (SC) with mono-chromotropic acid azo dyes, chromotrope 2B (I) and chromotrope 2R (II), and chromotropic acid bi-azo dyes, bis-3,6-(o-hydroxyphenylazo)-chromotropic acid (III), bis-3,6-(p-N,N-dimethylphenylazo)- chromotropic acid (IV) and 3-phenylazo-6-o-hydroxyphenylazo-chromotorpic acid (V) have been synthesized. Structural characterization of these novel sildenafil citrate ion-associates was carried out using elemental analysis and spectral techniques (VIS and IR). IR absorption spectra of the investigated ion-associates are studied and compared with those of the pure azo dyes and the drug. The spectral characteristics, oscillator strengths, transition dipole moments and resonance energy of the ion-associates in the ground state have also been calculated.
Keywords: sildenafil citrate, chromotropic acid azo dyes, Vis spectrophotometry, IR spectra.
Chromatographic retention data were measured for a chemically diverse set of organic solutes on an anhydrous 1-methoxyethyl-1- methylpiperidinium tris(pentafluoroethyl)trifluorophosphate, ([MeoeMPip]+[FAP]–), stationary phase at both 323 K and 353 K. The experimental retention factors were combined with previously published thermodynamic data and gas-to-water partition coefficient data to yield gas-to-anhydrous ionic liquid (IL) and water-to-anhydrous IL partition coefficients. The three sets of partition coefficient data were analyzed in accordance with the Abraham model. The Abraham model correlations that were determined in the present study describe the observed gas-to-([MeoeMPip]+[FAP]–) (log K) and water-to-([MeoeMPip]+[FAP]–) (log P) partition coefficient data to within average standard deviations of approximately 0.13 and 0.16 log units, respectively.
Keywords: chromatographic retention factors, partition coefficients, linear free energy relationships, ionic liquids
Materials and environmental chemistry
The precursor metal dihydrogen phosphate dihydrate was synthesized by a rapid and simple precipitation method using phosphoric acid, cobalt nitrate at ambient temperature (cobalt(II) was selected as model for metal in these investigations). The precursor was heated and sintered at different temperatures (600, 800, 1000 and 1100 °C) respectively, to optimize the conditions to obtain Co2P4O12 crystal form with high purity. The products were monitored by both of XRD, IR spectra by additional to accurate imaging via scanning electron microscope (SEM) and AFM-microscope to analyze surface topology and microstructural features of the metal cyclotetraphosphate. Structural investigations via XRD proved that the product obtained at 1100°C is the best and have fine structure with monoclinic structure phase and C12/c1 space group with lattice parameter a = 11.809(2), b = 8.293(1), c = 9.923(2) Å, respectively. A visualized investigations were performed to confirm structure validity and stability at sintering temperature (1100 °C) . Visualization studies indicated that variations in bond distances between Co1, Co2, P1 and P2 and different six oxygen atoms (O1 ,O2 , O3 ,O4 ,O5 and O6) inside crystal lattice are responsible for increasing lattice flexibility factor (by controlling in shrinkage and expansion coefficient) and consequently increase its bonds stability to break .
Keywords: Synthesis ; Ceramics ; Visualization; Metal cyclotetraphosphates; Structure
Industrial and engineering chemistry
The utilization of Fushun oil shale as raw material has been reviewed and the properties of Fushun shale oil and the developing history and the practical applicability of Fushun oil shale have been discussed. The complete utilization of Fushun oil shale sources has been evaluated.
Keywords: Fushun; shale oil; oil shale; review; utilization
In the present study, an estimation calculation system is described according to the literature reviews available in Asian and European countries on the minimization of industrial emissions. On the basis of the calculations done, an approach is described for the calculation of emissions, and the procedure mentioned in the article, and referred to the National Pollutant Inventory (NPI) is also described.
Keywords: Emission factor, emission estimation technique, emission factor code.
The utilization of wax as a raw material has been reviewed. Adding wax feedstock into rubber products, leather, food, synthesis of caster oil phosphate, tail gas recovery and electrodes has also been discussed. The complete utilization most of the wax sources in China has also been evaluated.
Keywords: China; wax; overview; utilization; feedstock