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The synthesis of modified mesoporous silica (SBA-15), a powerful and highly effective adsorbent, was provided for the preconcentration, extraction, separation, and determination of trace amounts of Ni (II) ions. In this method, SBA-15 modified with 1-(2-thiazolylazo)-2-naphthol (TAN) was used as a suitable absorbent. The absorption of Ni (II) ions was studied using the FAAS technique. Transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), energy-dispersive spectroscopy (EDS), Fourier-transform infrared (FT-IR) spectroscopy, and CHNS elemental analysis techniques were used to assess the characteristics of SBA-15 and TAN/SBA-15. Effective parameters (pH, amount of nanocomposite, extraction time, and type of recovery solvent) for extracting Ni (II) ions via TAN/SBA-15 were investigated. The merit figures of the method were obtained with appropriate results, such as detection limit, accuracy, enrichment factor, and preconcentration factor. The calibration curve was linear within the range of 5.0-50 ng mL-1 with a detection limit of 1.8 ng mL-1. High preconcentration, small relative standard deviations, and enrichment factors (approximately 100) were represented by the statistical analysis. The proposed method for measuring Ni (II) ions was used at trace levels in real samples, such as seawater, river water, well water, and wastewater from a textile factory, an electrical power station, an MDF factory, and a food industrial company, with satisfactory results. [ABSTRACT FROM AUTHOR]

In this study, new indenopyrimidin-1,2,4-triazol derivatives were synthesized in high yields using multicomponent reactions of ninhydrins, guanidine, alkyl bromides, aldehydes and hydrazonoyl chloride in the presence of Fe3O4/CuO/ZnO@Multi-Walled Carbon Nanotube Magnetic Nanocomposites (Fe3O4/CuO/ZnO@MWCNT MNCs) as a high performance catalyst in water at room temperature. The Fe3O4/CuO/ZnO@MWCNT MNCs was prepared using Petasites hybridus rhizome water extract as a green media and moderate base. This procedure had some benefits such as short reaction time, products with excellent yields, simple catalyst and products separation. The Fe3O4/CuO/ZnO@MWCNT MNCs was showed a good improvement in the yield of the product and displayed significant reusable activity as well. Investigation of antioxidant ability of synthesized compounds using radical trapping of diphenyl-picrylhydrazine (DPPH) and ferric reduction power experiment were another purpose in this research. Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication and applications of chemical products. Among solvents, water is a green solvents and very suitable for performing organic reaction. The present procedure avoids the use of toxic solvent. Substituted 1,2,4-triazoles and their derivatives are key skeleton of many biologically active molecules and important organic compounds that exhibit wide applications in pesticides, medicines, functional materials and organocatalysts. [ABSTRACT FROM AUTHOR]

In this study, we have researched the interaction of S[O.sub.2] molecule onto boron phosphide ([B.sub.12][P.sub.12]) and Ni-decorated [B.sub.12][P.sub.12] nanoclusters using density functional theory (DFT). While S[O.sub.2] has weak physisorption on the surface of pristine [B.sub.12][P.sub.12] (-7.4 kJ/mol), high chemisorption is found in the case of Ni-decorated [B.sub.12][P.sub.12] depending on the location of the Ni-decorated atom (-140.9, -167.7, and -166.5 kJ/mol). We found three major sites for appropriate decoration of Ni on the surface of a nanocluster, so we tried to find the maximum S[O.sub.2] adsorption of this modified surface by taking into account the calculations of adsorption energy, bond distance, dipole moment study, charge analysis, frontier orbital analysis, and density of states of all relaxed systems. Our observations reveal that Ni-decorated [B.sub.12][P.sub.12] are highly sensitive for S[O.sub.2] molecules, which is beneficial for design of sensitive sensor. Key words: transition metal, sulfur dioxide, nanocluster, [B.sub.12][P.sub.12], nickel. Nous utilisons l'approche de la theorie de la fonctionnelle de densite (TFD/DFT) pour faire des recherches touchant l'interaction de la molecule S[O.sub.2] sur du phosphure de bore ([B.sub.12][P.sub.12]) et des nano-agregats de [B.sub.12][P.sub.12] colores de Ni. Alors que S[O.sub.2] a une faible physisorption sur la surface du [B.sub.12][P.sub.12] pur (-7,4 kJ/mol), nous observons une forte chimisorption dans le cas du [B.sub.12][P.sub.12] colore de Ni, dependant de la localisation de l'atome Ni (-140,9 ; -167,7 et -166,5 kJ/mol). Nous trouvons trois sites majeurs pour une coloration appropriee de Ni sur la surface du nano-agregat, consequemment nous essayons de trouver l'adsorption maximale de S[O.sub.2] de cette surface modifiee en tenant compte des calculs d'energie d'adsorption, de la distance de liaison, de l'etude du moment dipolaire, de l'analyse de charge, de l'analyse des orbitales frontieres et de la densite d'etats des systemes de tous les systemes apres relaxation. Nous observons que le [B.sub.12][P.sub.12] colore de Ni est tres sensible aux molecules de S[O.sub.2], ce qui est tres interessant pour concevoir des senseurs sensibles. [Traduit par la Redaction] Mots-cles: metal de transition, dioxyde de soufre, nano-agregat ou nano-cluster, [B.sub.12][P.sub.12], nickel., 1. Introduction Sulfur dioxide (S[O.sub.2]) is a run-off from numerous industries and results in air pollution. Fuel burning is a main basis of S[O.sub.2], and results in a number of [...]

The preparation of pyrazinoquinazoline derivatives are performed in high yields by four component reactions of isoquinolin-3-ylmethanamine, α-haloketones, activated acetylenic compounds and ethyl bromoacetate in ionic liquid as green media at room temperature. In addition, due to having quinazoline core in the synthesized compounds, evaluation of antioxidant activity was performed by radical trapping by DPPH and reducing power of ferric ion experiments. As a result, synthesized compounds showed low radical trapping by DPPH and good reducing ability of ferric ion. The current procedure has the benefits for instance excellent yield of reaction, green media and easy separation of product. Ionic Liquid was used as solvent for the preparation of pyrazinoquinazoline as four cyclic heteroaromatic systems. The present procedure avoids the use of toxic solvent. The present procedure runs in ionic liquid as a green media. This recoverable ionic liquid makes this protocol attractive and useful as an industrially viable and eco-safe solvent with high yields of products. [ABSTRACT FROM AUTHOR]

The present work deals with a simple, inexpensive, sensitive, high performance and economic technique for extracting and preconcentrating trace quantity of PAHs compounds through glass foam modified with CTAB surfactant. Solution desorption was employed subsequently for transferring the extracted PAHs into a gas chromatography-mass spectrometry's injection port. BET, TGA, and FT-IR were used to characterize glass foam and CTAB/glass foam. Operative parameters in PAHs extraction and preconcentration such as amount of sorbent, pH, recovery solvent type, ionic power of solution, contacting time, and recovery time were enhanced to quantitatively determine PAHs. Analytical statistics of merit including limit of detection, accuracy, and linear range were determined to prove the suitability of our suggested technique. The CTAB/glass foam represented higher sensitivity to detect very lower concentration of PAHs such as phenanthrene, fluorene, pyrene and anthracene at ng mL-1 level with high accuracy for drinking water samples. [ABSTRACT FROM AUTHOR]

Pink Water lily flower, with the scientific name of Nymphaea alba in the family of Nymphaeaceae, was collected from North of Iran, Mazandaran in spring, dried in shade and powdered. The powdered flower material was extracted in 70% (vol/vol) ethanol. Acid functionalized multi-walled carbon nanotubes/CdO (MWCNTs-COOH/CdO) was fabricated by using the Water lily flower extract. The presence of CdO nanoparticles and their surface conjugation to MWCNT have been confirmed by FT-IR, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was used as a highly efficient catalyst for the synthesis of some pyrazolo[3,4-d]pyrimidine and pyrido[2,3-d]pyrimidine derivatives. These compounds were synthesized by the reaction of some substituted pyrazole or pyridine, thiourea and I2 in the presence of MWCNTs-COOH/CdO hybrid (5% mol) in warm water. The assigned structure was further established by CHN analyses, NMR and FT-IR spectra. [ABSTRACT FROM AUTHOR]

ABSTRACT The primary objective of this study was to explore the synthesis of novel dihydrocyclopenta[b]pyrrole derivatives with a high degree of efficiency. The work utilized a nanocatalyst composed of Ag/Fe3O4@MWCNTs in a multicomponent reaction including vinilydene aldehydes, ethyl 2‐amino‐4‐dioxo‐4‐arylbutanoates, and alkyl bromides. The reaction was carried out in aqueous solution at ambient temperature, leading to the formation of novel chemicals. The produced compounds exhibit antioxidant activity as a result of the evaluation processes performed on their NH group. Furthermore, an evaluation was performed on the antibacterial effectiveness of newly produced pyridines using a disk diffusion technique, utilizing two different strains of Gram‐negative bacteria. Significantly, the substances that were evaluated shown inhibitory effects on the development of Gram‐positive bacteria as well. This method has several benefits, including quick response times, high product yields, and easy separation of catalyst and product through simple procedures. [ABSTRACT FROM AUTHOR]

In the present study, trace amount of nickel (II) ions in real samples has been separated, preconcentrated and determined by a synthesized nanocomposite. Our suggested nanocomposite was prepared by immobilization of 2-aminopyrimidine on nanocellulose. The properties of nanocomposite were characterized by TEM, TGA, elementalanalysis CHNS, EDS, and BET techniques. The effective factors such as pH, nanocomposite amount, extraction time, eluent type, ionic strength and sample volume were optimized for quantitative determination of nickel (II) ions. The linear range of the calibration graph was between 5 and 500 ng mL-1 with limit of detection (LOD) 2.33 ng mL-1. Relative standard deviations (RSD) were 2.33%. Modified nanocellulose was used for measurement of the trace amounts of Ni (II) ions in the real samples such as human blood and urine with suitable fallouts. [ABSTRACT FROM AUTHOR]

In this study, a simple, sensitive, and high-performance method was employed to extract and preconcentrate ofI a trace amount of sodium barbiturate drug by using mesoporous silica (SBA-15) modified by graphene oxide (GO). TEM, BET, TGA, FE-SEM, EDS, and elemental analysis CHN were used to characterize mesoporous SBA-15 and nanocomposite. Effective parameters in barbiturate extraction such as pH, amount of nanocomposite, eluent type, contacting time, the ionic power of solution, and sample volume were optimized for quantitative determination of the barbiturate. Analytical figures of merit such as accuracy, limit of detection, preconcentration, and enrichment factors were calculated and proved the suitability of our proposed method. The calibration curve shows a linear correlation in the concentration range of 50-2000 ng mL-1 with the detection limit of 17 ng mL-1. The relative standard deviation (n=10) was calculated to be 1.39% and the preconcentration factor was achieved 50 using 100 mL of sample. [ABSTRACT FROM AUTHOR]