French-Ukrainian Journal of Chemistry
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High efficiency of calcined anionic clay to remove the chromate anions CrO42-from polluted water
Get PDFCalcined anionic clay based on zinc and aluminum was used to remove the pollutant CrO42- from wastewater. This adsorbent material derived from layered double hydroxide (LDH) was chosen for its higher adsorption capacity, its affinity for most pollutants, and its non-toxicity. The kinetic study suggesting a high affinity between the pollutant and calcined LDH (CLDH). The pollutant is retained in multilayer and follows the Freundlich model. Thermodynamic study indicates a physical interaction. The elimination reaches 100% with a retention capacity of 3333 mg/g. After cycles of regeneration and in comparison with other adsorbents, CLDH has proven its efficiency and high performances to remove CrO42- anions
Synthesis and transformation of 6-aminomethyl derivatives of 7-hydroxy-2'-fluoroisoflavones
Get PDFMannich aminomethylation of 8-methyl-7-hydroxy-2'-fluoroisoflavones applying bis-(N,N-dimethylamino)methane afforded C-6 substituted N,N-dimethylaminomethyl derivatives. Subsequent acetylation of these compounds in acetic anhydride in the presence of potassium acetate provided access to the corresponding acetoxymethyl derivatives that were converted to hydroxymethyl- and alkoxymethyl-substituted 7-hydroxyisoflavonoids. Addition of 3-(N,N-dimethylamino)-5,5-dimethyl-2-cyclohexen-1-one or 1,3-dimethyl-5-aminopyrazole with thermally generated ortho-quinone methides led to hetero-Diels–Alder or Michael adducts
Reduced graphene oxide contains a minimum of six oxygen atoms for higher dipolar strength: A DFT study
Get PDFThe present work focused on the reduced graphene oxide contains a minimum of six oxygen atoms for the higher dipolar strength. The ionization potential and electron affinity decreased only for the six oxygen atoms based graphene. The six oxygen atoms based graphene have the highest dipole moment. The reduced graphene has 0.25 eV bandgap, which is very suitable for electron transfer. The six oxygen atoms based graphene leads to the least gauge including atomic orbital (GIAO) rotational tensor; however, it has the highest isotropic polarizability difference, diamagnetic susceptibility tensor difference, paramagnetic susceptibility tensor difference, and total susceptibility. The C-C bond length has increased only for the six oxygen atoms based graphene
3-Thienyl/benzothienylchromones. Synthesis and properties
Get PDFThis mini-review for the first time summarizes and systematizes all the data available in the literature on the synthesis and properties of 3-thienyl/benzothienylchromones, starting from 1960. Two main approaches to the formation of target structures are presented. The conditions of cyclization reactions, oxidative rearrangement, transition metals catalyzed CH activation and annulation reactions, etc. are discussed. Testing data for some types of biological activity of a number of the 3-thienyl/benzothienylchromones and the products of their transformation into the pyrazole cycle are given
Quality assessment of some bottled water produced in Okitipupa, Ondo state, Nigeria
Get PDFThe aim of this study was to assess the safety level of some bottled water produced in Okitipupa, Ondo State Nigeria. Several packs of bottled water were obtained from three different manufacturers. Some physicochemical parameters and heavy metals were investigated to assess the quality of the bottle water using standard methods. The results from the physicochemical parameters and heavy metals were in with World Health Organization (WHO) standard for drinking water when compared. This study confirmed that the analyzed bottled water has good quality. Therefore, these bottled water are said to be safe for drinking
Phytochemical composition, antioxidant and antiproliferative activities of Rosmarinus officinalis leaves
Get PDFPhytochemicals in Rosmarinus officinalis leaves, their total phenolic content, antioxidant potential and antiproliferative activity against human prostate (DU145), colon (CT26) and cervical (HeLa 229) cancer cells were investigated. Extraction was done separately using hexane, dichloromethane, ethyl acetate and methanol. A total of 32 compounds were identified, eight of which were reported for the first time. The highest phenolic content was 476.80 ± 0.69 µg/ml for the methanolic extract which also had the highest antioxidant activity with a minimum inhibitory concentration of 5.39 ± 0.09 mg/ml. Extracts exhibited the highest toxicity against prostate cancer cells and the least against cervical cancer cells
Synthesis of 3-(2-Hydroxyphenyl)-5-(2-Pyridinyl)-1,2,4-triazoles as a potential chelate ligand for Uranyl ion
Get PDFTwo new uranyl complexes with the molecular formula [(UO2)(H2L1)](СH3OH) and [(UO2)(H3L2)](СH3OH) {H4L1 = 2-[5-[[5-[[5-(2-pyridyl)-1H-1,2,4-triazol-3‑yl]methyl]-1H-1,2,4-triazol-3-yl]methyl]-1H-1,2,4-triazol-3-yl]phenol and H5L2 = 2-[5-[[5-[[5-[[5-(2-pyridyl)-1H-1,2,4‑triazol-3-yl]methyl]-1H-1,2,4-triazol-3-yl]methyl]-1H-1,2,4-triazol-3-yl]methyl]-1H-1,2,4-triazol-3-yl]phenol)} have been synthesized. All compounds have been characterized by NMR and IR spectroscopy. With H4L1 and H5L2 uranyl ion forms mononuclear complexes. In [(UO2)(H3L2)](СH3OH) pyridyl nitrogen was uncoordinated and bonding of H5L2 was realized only through phenol oxygen and N4-nitrogens of triazole cycles
Drastic corrosive coliation of petroleum oils and the decay of metals
Get PDFIn the industry of petroleum oil refining industry the term of corrosion is frequently applicable regarding the several incidents because of the corrosiveness of petroleum oils due to the presence of trace corrosive compounds in such petroleum oils since the occurrences. Usually the corrosion is the results of chemical or electrochemical process of metals when it is exposing to the corrosive environment. The investigations of the impact of the organic acids, salts, elemental sulfur and the Mercaptans on the corrosion rates of seven different types of ferrous metals and the analysis of the nature of the corrosion between these materials were the objectives of the existing research. The relevant corrosive properties of two different types of selected crude oils and the chemical compositions of selected seven different types of ferrous metals were tested by the standard methods and instruments. A batch of similar sized metal coupons was immersed in both crude oil samples separately as three homogeneous metal coupons per each crude oil container. In order of after 15, 30 and 45 days from the immersion the corrosion rates of such metal coupons were determined by the weight loss method as three sets of samples while observing the corroded metal surfaces through an optical microscope. In addition, the decay of ferrous and copper from metals into crude oils while the interaction and the deductions of the initial hardness of metals were tested. As the basic investigations there were observed the relatively lower corrosion rates from stainless steels, relatively higher impact from salts on the metallic corrosion at lower temperatures, formations of FeS, Fe2O3, corrosion cracks and pitting, significant decays of ferrous and copper from some metals and the slight reductions of the initial hardness of metals after the interaction with the petroleum oils
Increasing the efficiency Proton exchange membrane (PEMFC) & other fuel cells through multi graphene layers including polymer membrane electrolyte
Get PDFMulti layers Graphene has been simulated theoretically for hydrogen storage and oxygen diffusion at a single unit of fuel cell. Ion transport rate of DFAFC, PAFC, AFC, PEMFC, DMFC and SOFC fuel cells have been studied. AFC which uses an aqueous alkaline electrolyte is suitable for temperature below 90 degree and is appropriate for higher current applications, while PEMFC is suitable for lower temperature compared to others. Thermodynamic equations have been investigated for those fuel cells in viewpoint of voltage output data. Effects of operating data including temperature (T), pressure (P), proton exchange membrane water content (λ) , and proton exchange membrane thickness on the optimal performance of the irreversible fuel cells have been studied.Obviously, the efficiency of PEMFC extremely related to amount of the H2 concentration, water activities in catalyst substrates and polymer of electrolyte membranes, temperature, and such variables dependence in the direction of the fuel and air streams
Physical and chemical properties of copper-zinc galvanic sludge in the process of thermal treatment
Get PDFThis academic work is focused on the study of physical-chemical patterns of copper-zinc galvanic sludge dissolution prior to and after thermal treatment in model solutions with a given pH. They show that all types of galvanic sludge eluates prior to and after thermal treatment are characterized by rather high concentrations of Cu2+ and Zn2+ ions. In acid eluates, the contents of zinc and copper ions are comparable. In extracts of distilled water and buffer solution, Zn2+ concentrations are higher than those of Cu2+. It has been established that the thermal treatment of galvanic sludge does not contribute to the retention of heavy metal ions in the sample. The intensity of dissolution of copper and zinc from galvanic sludge after thermal treatment increases with decreasing pH. It is proved that copper-zinc galvanic sludge presents a potential water-migration hazard