Applied Chemistry Today
Year:2019 | Volume:14 | Issue:51|Papers Count:24

In this research, through the condensation reaction of 3, 5-dichlorosalicylaldehyde with 1, 2-ethanediamine (en), 1, 3-propanediamine (pn) and 1, 4-butanediamine (bn), a serious of new N2O2 salophen type Schiff base ligands (csen = 6, 6'-((1E, 1'E)-(ethane-1, 2-diylbis(azanylylidene))bis(methanylylidene))bis(2, 4-dichlorophenol), cspn = 6, 6'-((1E, 1'E)-(propane-1, 3-diylbis(azanylylidene))bis(methanylylidene))bis(2, 4-dichlorophenol) and csbn = 6, 6'-((1E, 1'E)-(butane-1, 4-diylbis(azanylylidene))bis(methanylylidene))bis(2, 4-dichlorophenol)) were synthesized and characterized using FT-IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analysis. Also, their Ni(II), Cu(II) and Zn(II) complexes were synthesized and after characterization by elemental analysis and FT-IR spectroscopy, the structure of Zn(cspn) was determined by X-ray crystallography. The Schiff base ligand coordinated to the zinc ion through the phenolic oxygens, the azomethine nitrogens and the oxygens of two water molecules. Thus, the geometry around the central zinc ion was distorted octahedral. The in vitro antibacterial activities of the ligands and their complexes were evaluated against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The results showed that ligands and their complexes exhibited significant antibacterial activities, and also the gram-positive bacteria are more active than gram-negative bacteria.

Graphene oxide (GO) has a great potential to use as an adsorbent in sample preparation procedures. In this research, GO was used as an effective adsorbent in a simple GO-based dispersive micro-solid phase extraction technique coupled with high-performance liquid chromatography-UV detector (HPLC-UV) for the determination of diazepam. The prepared GO was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) techniques. Various experimental parameters affecting the extraction recovery were investigated and optimized. Under the optimized conditions, a linear response was obtained in the concentration range of 1– 100 ng mL− 1 with a detection limit of 0. 20 ng mL− 1. It also showed reproducible results with relative standard deviation of 3. 6 and 1. 3 % for 10 and 80 ng mL− 1 of Zn (II), respectively. The method was successfully applied to the diazepam analysis in biological and pharmaceutical samples.

Although oral drug delivery is the best choice, many pharmaceutical drugs such as anticancer have aromatic structure and so low solubility in water and biological fluid, which reduce the amount and rate of adsorption of these drugs and hence limits on their use in treatment. Nanoscience with unique characteristics has eliminated many of these problems. As with the use of nanoscale drug carries, many properties of drug such as solubility and half-life of the drug can be improved. Graphene and graphene oxide (GO) sheets have promising candidates to advance drug delivery platforms due to its two-dimensional structure, high chemical surface area, high chemical and physical stability, lower toxicity, and biocompatibility. One of the aims of designing drug delivery platform is to increase the effectiveness of the drug by focusing on the target tissue. Among the various type of magnetic nanoparticles, superparamagnetic iron oxide nanoparticles SPION due to its excellent magnetic properties, biocompatibility, biodegradability, and mobility in targeted area using external magnetic field, attracted a lot of attention. In the current study, we benefited from the use of graphene oxide Functionalized with γ-cyclodextrins, as carrier for SN38 and superparamagnetic iron oxide, which result shows covalent attachment of active drug molecule (SN38) to cyclodextrin-graphene oxide, increase the solubility of the drug and increase local temperature and hyperthermia following laser irradiation with a wavelength at 808 nm.

Abstract In this work, in order to investigate and optimize the dispersion temperature of the cyanocarbon compound(O-Chlorobenzylidene Malononitrile or OCBM), three methods of preparation of the sample with solid phase micro extraction, sampling using two-component vacuum traps and temperature scanning in the injection port using the gas chromatography apparatus used are located. The use of the OCBM cyanocarbon compound for testing chemical masks has been tested and tests have shown that in many centers, in order to disperse this compound in test chambers, it is placed in powder form on heaters with temperature high is used. There are assumptions that this dispersal technique at high temperatures may cause material damage, producing toxic substances, or creating unwanted reactions. Therefore, the other objectives of this paper were to analyze the vapors generated by the distribution of the OCBM produced by the cyanocarbon in the country with the above-mentioned method and the answer to the questions posed by these assumptions. For this purpose, preliminary information was obtained from the objective target temperature scan at the chromatography injection port, and then, in order to create the most similarity between the sampling conditions and the operating conditions used in the gas test chambers, the combination was placed on the heater. The mixture is evaporated and sampled using the highest possible temperature. In the final section of the paper, the solid-state micro-extraction method is used as an organic solvent-free preparation method for the extraction and detection of low-concentration compounds produced in the dispersion process.

In this paper, five superabsorbent polymers prepared by dispersing watermelon shell powder (WSP) and cucumber shell powder (CSP), mixture bentonite and WSP, mixture bentonite and CSP, zeolite (Z) bentonite (B), into poly(acrylamide-co-acrylic acid) (P) backbone in an aqueous medium through a chemical cross-linking method named as P-WSP-CSP، P-WSP-B، P-CSP-B، P-Z، P-B have been investigated. Polymeric nanocomposites have been synthesized through chemical cross-linking by polymerization technique using N, N-methylenebis acrylamide as a cross-linker and potassium persulfate as an initiator in a simple aqueous environmental conditions. These superabsorbent polymeric nanocomposites were characterized by X-ray diffraction, Fourier transform infrared and field emission-scanning electron microscope measurements. The water absorption and desorption of the superabsorbent polymer nanocomposites have also been studied. Our findings show that very high water absorption and lower drying rate of P-CSP-B are attributed to higher porous surfaces observed in FE-SEM images. The results show the superabsorbent polymers based on CSP represent very high water absorbency capacity and water retention ability that make them suitable for technology applications.

In this study, the interaction of Schiff base Exo-Vanadium Complexes from salicylidine derivatives with cytomegalovirus DNA (ct-DNA) was investigated by ultraviolet-spectroscopy and fluorescence spectroscopy. Using the results of these empirical studies, the coupling mechanism between the two chlorine derivatives and the bromo derivative of the schiff base complexes with DNA, the constant binding of the ligand to the DNA, and the number of binding sites (n) were investigated. The fixed binding values (kb) and (kf) obtained from ultraviolet-light spectroscopy studies and fluorescence spectroscopy for Chromine derivatives are larger than the Barmox derivative, which suggests further interactions between the chlorine complex and DNA. The antimicrobial activity of the Schiff base Vanadil Complex, on the gram-positive bacteria of Staphylococcus aureus and the worm-negative bacteria of Escherichia coli, was studied and compared with the standard antibacterial materials. Based on the results, both schiff base vanadium complexes of the study are approximately equal to the amount of good antibacterial activity, with the difference that the derivative contains a functional group of chlorine has more antibacterial activity than the derivative containing the bromine functional group against the bacteria Is negative. From these observations, it can be concluded that the antibacterial activity of these complexes is related to the presence of Cl and Br substituents.

Treatment of the fiber factories wastewater, due to the high amount of COD, is essential. This research involves COD reduction from the wastewater of Parsian Khavaran fibers factory, using hybrid system of adsorption onto magnetic activated carbon and membrane. The magnetic activated carbon was derived from pistachio nut shell through chemical activation process (with phosphoric acid) and co-precipitation method. Scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, BET analysis and vibrating sample magnetometer (VSM) were used for magnetic activated carbon characterization. According to the results, the surface of the magnetic activated carbon was uniformly porous, including spherical particles of diameter 40-70 nm. The BET surface analysis showed that the specific surface area and the total pore volume were 479. 59 m2g-1 and 0. 665 cm3g-1, respectively, and considering the VSM analysis, the magnetization of the magnetic activated carbon was determined equal to 4. 615 emu g-1. Moreover, the effect of pH and adsorbent concentration on COD reduction were discussed. Consequently, the maximum reduction of COD took place in neutral condition with the concentration of 17 g/l of magnetic activated carbon.

L-Cysine (L-Cys) is one of the most important amino acids in the body and plays an important role in the immune system. In this study, the platinum electrode was modified by a Ni-Al double-layer hydroxide film (Pt /NiAlLDH) and used to measure L-Cys. Pt/NiAlLDH showed good catalytic activity for the oxidation of L-Cys. On this electrode, the oxidation of L-Cys occurs at a potential very lower than an unmodified platinum electrode, which occurred at about 500 mV. The catalytic oxidation peak currents depend on the L-Cys concentration with a logarithmic linear relation in the concentration range of 1×10-7 to 2. 5×10-4 M and an experimental detection limit of 1×10-7 M. The proposed electrode was used for determination of L-Cys in a drug sample. This modified electrode is cheap and is quickly and easily prepared.

Bioorthogonal reactions are known as types of chemical reactions without the interference from biological reactions within the living systems. The requirements for such reactions include activities in aqueous environment, mild temperature, and physiological pH. One of the facile ways, for detecting bioorthogonal reactions, is covalently attaching a florescent compound to biomolecules such as proteins. In this work, two novel derivatives of fluorescein, 5(6)acylchloride fluorescein and 5(6)thiophenol fluorescein, were synthesized. The products were confirmed using 1H NMR. Subsequently, the reactions of the synthesized derivatives of with Bovine Serum Albumin (BSA) and Hen Egg white lysozyme (HEWL), under physiological conditions, were investigated. The advantages of reactions of the derivatives with proteins can include selectivity towards lysine, high kinetics of reactions, and low concentrations of reactants. The fluorescein-attached proteins were purified using size-exclusion chromatography and dialysis. The success of covalent attachments to proteins was confirmed using SDS-poly acrylamide gel electrophoresis. The reactivity of 5(6)thiophenol fluorescein towards BSA was investigated at pH 7 and pH 9.

Fuel cells are the electrochemical devices for the direct conversion of the chemical energy in the fuel into high-efficiency electricity, which requires a high-efficiency catalytic converter. In this study, graphene oxide was first reduced by electrochemical method on the pencil graphite electrode, and then the Cobalt nanoparticles were deposited on the reduced graphene oxide with electrochemical deposition method. Finally, the hollow platinum nanoparticles were created by the Galvani displacement reaction of platinum ions with nanoparticles of cobalt. Optimization of the electrode components was done by the central composition design method. In order to investigate the structure and microstructure of synthesized electrocatalyst, the techniques of field emission scanning electron microscopy and transmitted electron microscopy were used. The obtained electronic images represent the uniform dispersion of nanoparticles on the pencil graphite electrode. The results of the electrochemical tests indicate the proper performance of the catalytic surface and its high stability as a working electrode in the reaction of hydrogen evolving in a three-electrode system.

Smart water flooding is an enhanced oil recovery (EOR) technique which has gained more attention in research activities, recently. Despite many efforts on the study of fluids interaction in this process, most of the presented results are sparse, as they are not probing to the basics of transport phenomena between the involved phases. This work is aimed to bring new understanding of fluid-fluid interaction during smart water flooding through a series of organized experiments in which a crude oil sample with known properties was preserved in contact with different smart water composition for 45 days. Measuring brine pH illustrates the strong effect of the contact time and brine composition on partitioning of crude oil polar components. By increasing the concentration of divalent ions the dissociation of Naphthenic Acids (NAs) increase. To verify this important finding, ultraviolet-visible (UV-Vis) spectroscopy on aged brine samples were performed. Besides, the interfacial tension (IFT) measurements were conducted to identify the impact of the dissociation of crude oil polar components on interfacial interactions. Results show that the sulfate ion has the maximum effect on not although dissociation of polar components, but also on smart water-crude oil IFT reduction. Presence of a divalent cation is necessary for improving the effect of sulfate ion. Also the results show that presence of monovalent ions may affect the adsorption of polar components toward the interface, hence reduces the brine-crude oil IFT.

Polyaniline and their nanocomposites were prepared by using chemical oxidative polymerization method in the presence of potassium iodate as oxidant. In this research, morphology and chemical structure of polyaniline/polystyrene and polyaniline/polyvinyl chloride was studied. Also, the capability of these nanocomposites to removal of zinc & lead cations from aqueous solution was studied. In order to adsorption of metal cations from aqueous solution, batch system was used & various experimental parameters such as ph, cationic pollutants dosage and contact time was evaluated. Results indicated that the highest adsorption rate for zinc and lead cations by polyaniline/ polyvinylchloride adsorbent was calculated 95. 86 and 93. 4, respectively. The optimum condition for lead cation adsorption were achieved using a polyaniline/polyvinyl chloride adsorbent at pH 7, a cation concentration of 100 mg/L and contact time of 20 minutes. Also, the study of adsorption isotherm equations has shown that the Freundlich equation is better compatibility with experimental data.

In this research, the electrochemical oxidation of mesalazine was investigated in presence and absence of benzenesulfinic acid and 4-toluenesulfinic acid as a nucleophile using cyclic voltammetry and controlled-potential coulometry. The results indicate that quinoneimine generated by oxidation of mesalazine, participates in reaction with arylsulfinic acids via Michael addition reaction in a ECC electrochemical mechanism pattern. To approve the proposed ECC mechanism, electrochemical synthesis of oxidation of mesalazine was also performed in the presence of benzenesulfinic acid and the obtained product, was identified by of FT-IR and mass spectrometry spectra. Homogenous rate constants (kobs) of Michael addition reaction for quinoneimine generated by oxidation of mezalasine with arylsulfinic acids, were estimated by cyclic voltamogram digital simulation method.

The leaves of Juglans regia L. (walnut) is known for its diverse effects in drug therapy and traditional medicine. This plant has good antioxidant and antimicrobial properties. In this study, extract of leaves of walnut from different regions of Iran was analyzed by high performance liquid chromatography-mass spectrometry. Samples were tested for their free radical scavenging activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay and by numerous linear multivariate calibration techniques to identify the peaks potentially responsible for the antioxidant activity from chromatographic fingerprints. From the studied techniques, independent component regression (ICR) was preferred to exhibit the potential antioxidant active compounds in samples because of its high repeatability, simplicity, and interpretability of the regression coefficients.

In this work, with a simple and mild method, 1, 5-benzodiazepine compounds were synthesized using the condensation of o-phenylenediamine derivatives and liner and cyclic ketones in the presence of the metal-organic framework Zn3(BTC)2 in ethanol at 50 ° C. All products with excellent yields (86-94%) were obtained. Nanoparticles Zn3(BTC)2 have the advantages such as non-toxic, stable in solvents and harsh conditions, easy synthesis, high activity, easy separation from the reaction mixture by filtering and recyclable without losing its activity. In this work, with a simple and mild method, 1, 5-benzodiazepine compounds were synthesized using the condensation of o-phenylenediamine derivatives and liner and cyclic ketones in the presence of the metal-organic framework Zn3(BTC)2 in ethanol at 50 ° C. All products with excellent yields (86-94%) were obtained. Nanoparticles Zn3(BTC)2 have the advantages such as non-toxic, stable in solvents and harsh conditions, easy synthesis, high activity, easy separation from the reaction mixture by filtering and recyclable without losing its activity.

Modification of a glassy carbon electrode with multiwall carbon nanotube and a thin film of polyPoly[Co(Phen)3] was proposed as an electrochemical insulin sensor. For electropolymerization of Poly[Co(Phen)3]2+, 10 cyclic voltammetry were applied with scanning speed 0. 5 V/S and range of potential-0. 3 and 0. 85 V relative to the reference electrode Ag / AgCl in phosphate buffer solution 0. 05M, pH=4/7. The modified electrode showed an excellent selectivity and sensitivity toward insulin with a wide linear range 1. 67-0. 741 and 0. 099-. 654 µ M and a very low detection limit of 8 nM. The proposed method is accurate, simple, cheap and could be used for determination of insulin in real samples such as blood samples.

Uranium is a radioactive and toxic element and commonly exists in the environment in the U(VI) and U(IV) oxidation states. The most stable chemical species in aqueous solution under oxic conditions is the uranyl ion UO22+. In this research an electrochemcal sensor based on chemically reduced graphene oxide (RGO) for sensetive determination of UO22+ was prepared. The electrochemical behavior and determination of uranyl ion on surface of graphene paste electrode in the potential range of-0. 8 to 0. 8 (v) was studied by cyclic and differential pulse voltammetery. The effects of various parameters such as pH and scan rate were investigated. The response of the sensor was found to be linear in the range of uranyl concentrations from 1. 0 to 600  M. The detection limit (S/N=3) is calculated 0. 7  M. A sensor shows a good repeatability (RSD of 0. 9% (n=6)). The sensor was successfully applied for determination of uranyl in water and soil samples.

Polyaniline/Co(II) metal-organic framework composites (PANI/x%Co-MOF) were synthesized by hydrothermal preparation of Co(II) metal-organic framework in the presence of as-prepared polyaniline. The composites were characterized using powder X-ray diffraction (PXRD), fourier-transform infrared (FT-IR), scanning electron microscopy (SEM), and Co elemental EDS-mapping. Crystal stability of Co(II) metal-organic framework in the composites was confirmed by powder X-ray diffraction. The Co elemental EDS-mapping shows that the cobalt is uniformly dispersed in the polymer matrix. Electrochemical properties of prepared composites were evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge methods in a conventional three-electrode system. The results of electrochemical studies showed that the PANI/50%Co-MOF composite has the highest specific capacitance, 144 F g-1, at 1 A g-1 current density in KNO3 (3 M) electrolyte. The composite electrodes have shown a higher capacity than pure polyaniline and Co(II) metal-organic framework, due to the synergistic effects.

In this work, a complex of two-dimensional coordination polymers of manganese (II) was prepared using an organic ligand containing attachment atoms, O, N and anion Tiocyanate as an auxiliary ligand and crystal to crystal transformation were investigate. Infrared analysis combined with elemental analysis indicated that the desired compound was formed. Determining the structure of single crystals prepared by X-ray crystallography represents a deformed octahedral structure around the manganese atom. Due to simultaneous presence of the hydrogen peroxide receptor group on the organic binding agent, the effect of weak interaction and hydrogen bonding on the stability of the final structure is evident.

Today, the use of medicinal plants has been considered by the researchers due to the reduction of side effects. Syrian rue has long been used to disinfect. The aim of this study was to investigate the effect of silver nanoparticles on the antimicrobial activity of Syrian rue against E. coli. First, silver nanoparticles were prepared by a new green method and then used to produce silver nanoparticles/Syrian rue extract composite. Antibacterial process was performed using diffusion method on Mullerinton medium. Due to the lack of growth around the discs, which shows the antagonistic effects of silver nanoparticles and the extract of Syrian rue, the antimicrobial activity of the nanocomposite is higher than that of each of the silver nanoparticles and Syrian rue plant separately.

The Rh(III) complex[Rh(py)2(CH3CN)Cl3], Where py is pyridine has been prepared and characterized by elemental analysis, IR, and electronic absorption spectroscopies, and X-ray crystallography. The crystal structure of [Rh(py)2(CH3CN)Cl3] shows that the coordination geometry around the Rh(III) is a distorted octahedron. The title complex crystallized in monoclinic, space group P21/c, Z = 4, a = 7. 626 (15) Å , b= 27. 525(6) Å , c= 7. 712 (15) Å and β =14. 07(3)° . Electronic spectrum of the complex show that ligand – centered ( LCT ) transitions and metal-to-ligand charge transfer ( MLCT ). The molecular modeling of the complex was studied using a theoretical method and there was a good agreement between the results of the theory and the results of X-ray diffraction. Antibacterial activity of the complex has also been studied against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus ) and Gram-negative bacteria ( Pseudomunas aeroginosa and Escherichia coli).

Two new branched hexadentate amines, 4, 7-bis (2-pyridylmethyl)-4, 7-diazaundecane-1, 10-diamine (L5) and 5, 8-bis(2-pyridylmethyl)-5, 8-diazadodecane-1, 12-diamine (L6), have been synthesized. Condensation with 2-hydroxy-5-methylisophthalaldehyde in the presence of manganese(II), zinc(II) and cadmium(II) ions in methanol leads to produce six new Schiff base macrocyclic complexes [MSb1]2+ and [MSb2]2+ with two 2-pyridylmethyl pendant arms. The resulting compounds were characterized by IR, elemental analysis, Mass and by 1H and 13C NMR in the case of Cd(II) and Zn(II). These compounds are quite stable in air and can be stored in a desiccator for long periods without decomposition. The synthesized complexes were screened for their antibacterial activities against four bacterial; (Escherichia coli) PTcc 10009, ) Bacillus cereus (ATCC 7064, ) taphylococcus subrogation (Lio) و Staphylococeus aureus (ATCC 6633, strains and the complexes showed antibacterial effects.

The pyranopyrazoles and their derivatives, are an important biological active compounds in pharmaceuticals, and used as major structure for a lot of bioactive products in organic synthesis. Herein, we report an efficient synthesis of a new class of pyranopyrazole derivatives via a catalyst free one-pot reaction in ethanol at reflux. We have prepared new pyrano[2, 3-c]pyrazole derivatives by using catalyst-free one-pot reactions. The mild reaction conditions, short reaction times, good to high yields, simple workup procedure, and no need to chromatography are the significant advantages of this study. The structure of the synthesized compounds were recognized from their IR, 1H-NMR, 13C-NMR spectra data.

The synthesis of ten novel azo dyes derived from 9-Aryl-1H-xanthene-1, 8(2H)-dione derivatives from one equivalent of azo-linked salicylaldehydes and two equivalent of dimedone in the presence of 3, 3'-(butane-1, 4-diyl)bis(1, 2-dimethyl-1H-imidazol-3-ium)hydrogensulfate, as a green media, in short reaction time and high yield is reported. Azo-linked aldehydes containing electron withdrawing groups (such as nitro and halide) or electron releasing groups (such as methyl and methoxy group) were employed and reacted well to give the corresponding xanthenes in the yields ranging from 82 to 95%. This method provides several advantages such as environmental friendliness, solvent free, simple work-up, and mild reaction condition. All of synthesized compounds were characterized by FT-IR, 1HNMR and 13CNMR spectroscopy and elemental analyses.