Showing papers in "Synthesis and Reactivity in Inorganic Metal-organic and Nano-metal Chemistry in 2012"
TL;DR: In this article, the synthesis of magnetic nanoparticles (Fe3O4) and their coating with cetyltrimethyl ammonium bromide (CTAB) has been reported.
Abstract: The synthesis of magnetic nanoparticles (Fe3O4) and their coating with cetyltrimethyl ammonium bromide (CTAB) has been reported in this study. The synthetic iron oxide nanoparticles were characterized using FTIR, streaming current potential (SCP) and X-ray diffraction techniques. Particle size distribution of bare and coated nanoparticles was investigated by dynamic light scattering (DLS) technique and transmission electron microscopy (TEM). The results obtained revealed that the CTAB modification effectively decreased the particle size and enhanced the dispersion of the particles in solution. In addition, simple separation by using a magnetic field was achieved because CTAB did not alter the superparamagnetic properties of particles.
48 citations
TL;DR: A supramolecular CuII complex, [Cu(L)(H2O)] (H2L: 4,4′,6,6′-tetrachloro-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized.
Abstract: A supramolecular CuII complex, [Cu(L)(H2O)] (H2L: 4,4′,6,6′-tetrachloro-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol), has been synthesized and structurally characterized. X-ray crystallographic analysis shows that the complex is a centrosymmetric mononuclear CuII complex, and the CuII atom is penta-coordinated by two phenolic O atoms and two oxime N atoms from the deprotonated Salen-type ligand, and one oxygen atom from the coordinated water molecule. A self-assembling continual supramolecular structure is formed by intermolecular O3-H3···O2 and O3-H3···Cl1 hydrogen bonds.
43 citations
TL;DR: In this article, the results showed that particle size of product could be tuned by reaction parameters such as electrolysis voltage and oxalate concentration, and the average particle size was about 22 nm.
Abstract: Electrosynthesis has been proposed to preparation of copper oxalate nanoparticles in different sizes by electrolysis of copper plate as anode in sodium oxalate solution. The results showed that particle size of product could be tuned by reaction parameters such as electrolysis voltage and oxalate concentration. Detailed particle size of compound as a function of electrolysis voltage shows that increasing voltage from 8 to 20 V decreases particle size of CuC2O4. Also, particle size of produced copper oxalate at a constant voltage depended on concentration of oxalate solution. Under optimum condition the average particle size of product is about 22 nm.
36 citations
TL;DR: In this paper, a review demonstrates the importance and various roles of polyoxometalates (POMs) in the development of nanotechnology, focusing on the synthesis of silver, gold, selenium, cadmium sulfide, palladium, and calcium carbonate nanoparticles using POMs.
Abstract: Recent developments in the synthesis of nanoparticles using polyoxometalates (POMs) are reviewed. This review demonstrates the importance and various roles of POMs in developing of nanotechnology. Special attention has been paid to the synthesis of silver, gold, selenium, cadmium sulfide, palladium, and calcium carbonate nanoparticles using POMs.
35 citations
TL;DR: The microhardness of EL Ni-B-Si3N4 composite coating in its as-plated condition is 632 ± 17 HV0.1 as discussed by the authors.
Abstract: Deposition of electroless (EL) Ni-B-Si3N4 composite coating and its characteristic properties are addressed.Hydrogen evolution limits the level of incorporation of Si3N4 particles in the EL Ni-B matrix to 2 wt%. Incorporation Si3N4 particles increased the surface roughness of the matrix but did not influence its structure. The microhardness of EL Ni-B-Si3N4 composite coating in its as-plated condition is 632 ± 17 HV0.1. Heat treatment at 350 and 450°C for 1 h increased its hardness. Adhesive wear is the predominant wear mechanism of EL Ni-B-Si3N4 composite coating. Its corrosion protective ability did not differ much with its plain counterpart.
30 citations
TL;DR: In this article, the authors investigated the biosynthesis of gold nanoparticles by Streptomycec griseus and found that after 48 hours, the extracellular production of gold particles with good monodispersity, spherical shape, and average size of 50nm.
Abstract: The biosynthesis of gold nanoparticles would benefit from the development of clean, nontoxic, and environmentally acceptable procedures concerning microorganisms from bacteria to fungi. Streptomyces are saprophyte bacteria that have the enormous ability to produce secondary metabolites such as vitamin B, antibiotics, and antifungi. The authors investigated biosynthesis of gold nanoparticles by Streptomycec griseus. The UV–vis and XRD spectra of the aqueous medium containing Streptomycec griseus and 1 mM HAuCl4 demonstrated the formation of gold nanoparticles after 48 h. Transmission electron microscopy micrographs showed extracellular production of gold nanoparticles with good monodispersity, spherical shape, and average size of 50 nm.
28 citations
TL;DR: Silica-supported Preyssler nanoparticles (SPNP) was found to be an inexpensive and effective catalyst for the rapid, one-pot three-component synthesis of N-substituted 1,8-dioxodecahydroacridines in high yields as discussed by the authors.
Abstract: Silica-supported Preyssler nanoparticles (SPNP) was found to be an inexpensive and effective catalyst for the rapid, one-pot three-component synthesis of N-substituted 1,8-dioxodecahydroacridines in high yields, with easy workup procedure. The nanocatalyst was easily separated from the reaction mixture and was recycled a couple of times without any appreciable loss in activity. In addition, water as a green solvent was a solvent of choice.
27 citations
TL;DR: In this paper, the structural, optical, and magnetic properties of MgFe2O4 prepared by a ceramic technique have been investigated and the Me-O and Me-Me bond lengths increase with the addition of Cu.
Abstract: The addition of Cu on the structural, optical, and magnetic properties of MgFe2O4 prepared by a ceramic technique has been investigated. The Me-O and Me-Me bond lengths increase with the addition of Cu. IR spectra show bands at 540 and 460 cm−1, which confirm Fe3+ ions in both tetrahedral and octahedral sites. Room temperature Mossbauer spectra of MgFe2O4 compounds in zero applied magnetic field show the general trend of increasing hyperfine value and A-B exchange interaction caused by Mg2+ ion with Fe3+ ions. The addition of copper increases the isomer shift and quadruple splitting of the doublet.
23 citations
TL;DR: In this article, α-Fe2O3 nanoparticles were synthesized using the hydrolysis method and used to modify glassy carbon (GC) electrode and the modified electrode was used to detect uric acid (UA) by cyclic voltammetry (CV) and chronoamperometry (CA).
Abstract: α-Fe2O3 nanoparticles were synthesized using the hydrolysis method. The prepared sample was characterized by various techniques. The synthesized nanoparticles were used to modify glassy carbon (GC) electrode and the modified electrode was used to detect uric acid (UA) by cyclic voltammetry (CV) and chronoamperometry (CA). At the modified GC electrode, UA is oxidized with less positive potential than the bare GC electrode. The effect of scan rate and the substrate concentration on the modified electrode have also been discussed. The electrochemical studies revealed that the product will exhibit potential applications in the development of sensors.
23 citations
TL;DR: The synthesis of amino-acid-capped gold nanoparticles (GNPs) and their characterization using agarose gel electrophoresis are reported and it is revealed that the interactions between L-Arginine, L-Glutamic acid, and GNPs were of the electrostatic and covalent/ coordinate types, respectively.
Abstract: The synthesis of amino-acid-capped gold nanoparticles (GNPs) and their characterization using agarose gel electrophoresis are reported. The GNPs were capped with L-Arginine and L-Glutamic acids at different pH. At the physiological pH, the results obtained revealed that the interactions between L-Arginine, L-Glutamic acid, and GNPs were of the electrostatic and covalent/ coordinate types, respectively. The capped GNPs possessing free amine/carboxylic groups could play an important role in conjugating biomolecules (e.g., proteins) in various nanobiotechnological applications. In addition, if the pH of the target environment is constant, capped GNPs bound electrostatically are preferred and when variable, then amino-acid-capped GNPs bound covalently/ coordinately are recommended.
22 citations
TL;DR: In this article, the effects of reaction temperature, reaction concentration, surfactant concentration, refluxing time, seed-mediated growth, and heating rate on the size and morphology of monodisperse iron oxide nanoparticles synthesized by thermal decomposition of iron oleate complex through "heating-up" process were demonstrated.
Abstract: We have demonstrated the effects of reaction temperature, reaction concentration, surfactant concentration, refluxing time, seed-mediated growth, and heating rate on the size and morphology of iron oxide nanoparticles synthesized by thermal decomposition of iron oleate complex through “heating-up” process. By precisely controlling the reaction parameters, monodisperse iron oxide nanoparticles with the sizes ranging from 7 to 35 nm and controllable shapes are obtained. The formation kinetics of monodisperse iron oxide nanoparticles is experimentally studied and discussed. The results can be helpful in generally understanding the mechanism of thermal decomposition method.
TL;DR: In this paper, the influence of urea presence on morphology and particle size of the as-prepared zinc oxide was also investigated and the results revealed that the morphology of the prepared ZnO samples is susceptible to the reactant conditions.
Abstract: Zinc oxide nanostructures have been successfully prepared through dissolving of microsized zinc xide powder in ammonium hydrogencarbonate solution at 25°C, followed by calcination of the resultant precipitates at 350°C for 1 h The influence of urea presence on morphology and particle size of the as-prepared zinc oxide was also investigated The obtained products were characterized by XRD, SEM, FT-IR, UV-Vis, and Brunauer–Emmett–Teller (BET) N2 adsorption method The results revealed that the morphology of the as-prepared ZnO samples is susceptible to the reactant conditions It was found that the crystallite size of the prepared samples decreases by increasing of ammonium hydrogencarbonate, urea, and ZnO amount
TL;DR: In this paper, a novel nanocomposite hydrogel was prepared by in situ radical polymerization of acrylamide monomers in the suspension of laponite clay without any chemical crosslinkers.
Abstract: A novel nanocomposite hydrogel was prepared by in situ radical polymerization of acrylamide monomers in the suspension of laponite clay without any chemical crosslinkers. Comparing with pure poly(acrylamide) hydrogel, adsorption ability toward the cationic dye was improved significantly. With the increase of laponite content, there had no obvious increase of adsorption toward basic fuchsin. With the increase of acrylamide monomer from 0.5 to 2.5 g, the adsorption toward basic fuchsin was increased from 4.62 to 24.45 mg/g. When the pH value of basic fuchsin solution was varied from 7.5 to 3.0, the adsorption toward basic fuchsin was decreased from 23.77 to 12.67 mg/g. When the temperature of dye solution was increased from 30 to 60°C, the adsorption toward basic fuchsin was increased from 20.16 to 22.60 mg/g. Such material is expected to be a good adsorbent for water pollutants such as cationic dyes and treatment of these organic contaminants from wastewater.
TL;DR: Tetrabutylammonium hexatungstate [TBA]2[W6O19] has been efficiently used as catalyst for the synthesis of electrophilic alkenes via the Knoevenagel condensation reaction of aromatic aldehydes with malononitrile.
Abstract: Tetrabutylammonium hexatungstate [TBA]2[W6O19] has been efficiently used as catalyst for the synthesis of electrophilic alkenes via the Knoevenagel condensation reaction of aromatic aldehydes with malononitrile. The catalyst shows high catalytic activity with good to excellent yields of the desired products. Moreover, the catalyst could be recycled three times without noticeably decreasing the catalytic activity.
TL;DR: In this paper, the Zn and Zn-TiO2 composite coatings were fabricated by electrolyzing respective plating solutions of Zn, and the surface morphology of deposits was studied by scanning electron microscopy, energy-dispersive X-ray diffraction spectroscopy, and X ray diffraction techniques.
Abstract: The Zn and Zn-TiO2 composite coatings were fabricated by electrolyzing respective plating solutions of Zn and Zn-TiO2. The rutile TiO2 nanoparticles (size ≤100nm) were used for the preparation of composite coatings. The corrosion behavior of the deposits was examined by electrochemical methods. The anticorrosive property of coatings was supported by measuring their corrosion potential, polarization resistance, charge transfer characteristic peak and break frequency. The surface morphology of deposits was studied by scanning electron microscopy, energy-dispersive X-ray diffraction spectroscopy, and X-ray diffraction techniques. The change in morphology of Zn-TiO2 composite with respect to Zn is correlated with their corrosion behavior.
TL;DR: An efficient Hantzsch four-component condensation reaction for the synthesis of polyhydroquinoline derivatives was found to proceed in the presence of iron (III) phosphate in ethanol under reflux condition.
Abstract: An efficient Hantzsch four-component condensation reaction for the synthesis of polyhydroquinoline derivatives was found to proceed in the presence of iron (III) phosphate in ethanol under reflux condition. The method is really simple and environmentally benign. The keys features of this protocol are the use of a heterogeneous and reusable catalyst, high yields of products, nontoxic solvent, and short reaction times from the principles of green chemistry point of view.
TL;DR: Transmission electron microscopy illustrated the production of intracellular gold nanoparticles with the size range of 100–200 nm in spherical, triangle, and rod shapes and exhibited maximum absorbance at 550 nm in UV-vis spectroscopy.
Abstract: Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. The authors investigated biosynthesis of gold nanoparticles using the fungus Phoma macrostoma. Intracellular biosynthesis of gold nanoparticles was obtained by incubating HAuCl4 solution with the fungal biomass for 48 h. The gold nanoparticles exhibited maximum absorbance at 550 nm in UV-vis spectroscopy. The XRD spectrum showed Bragg reflections corresponding to the gold nanoparticles. Transmission electron microscopy illustrated the production of intracellular gold nanoparticles with the size range of 100–200 nm in spherical, triangle, and rod shapes.
TL;DR: In this paper, the authors have synthesized silver and gold nanoparticles (AgNPs and AuNPs) by using rhizome extract of Dioscorea batatas at 50°C (AuNps), AgNPs was carried out at 80°C as well as room temperature (25°C).
Abstract: Development of biologically inspired experimental process for the synthesis of nanoparticles is an important branch of nanotechnology. Here the authors have synthesized silver and gold nanoparticles (AgNPs and AuNPs) by using rhizome extract of Dioscorea batatas at 50°C (AuNps), AgNPs was carried out at 80°C as well as room temperature (25°C). The reductions of Ag and Au ions were observed by the color changes from colorless to brownish yellow, and dark yellow and dark red wine, respectively. The reaction was followed with the help of UV-visible spectrometer. The synthesized nanoparticles were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscope analysis. The authors did not find, formation of gold nanoparticles at room temperature. Furthermore, this green biogenic approach is rapid and simple alternative to chemical synthesis methods.
TL;DR: Aluminum trisec-butoxide (ALTSB), aluminum ethoxide and aluminum isopropoxide were used to prepare defect free, meso-porous membrane following dip-coating, drying and sintering as mentioned in this paper.
Abstract: Aluminum tri-sec-butoxide (ALTSB), aluminum ethoxide (ALET) and aluminum isopropoxide (ALISP) were used to prepare defect free, meso-porous membrane following dip-coating, drying and sintering. The membrane contained pores larger than 2 nm with either cylindrical pores open at both ends or ink bottle shape. Although ALISP suspension exhibited smaller particle size than ALTSB, both precursors produced membranes that exhibited similar pore size and pore size distribution pattern after the membranes were sintered. ALTSB produced membrane that exhibited the highest surface area. ALET membrane exhibited the largest pore size, broadest pore size distribution and smallest surface area at all calcination temperatures.
TL;DR: In this article, the morphology and stability of the materials were characterized by scanning electron microscope and thermogravimetric analysis, and electrical conductivity and mechanical properties of the composites were also investigated.
Abstract: NanoGs-PPy/epoxy nanocomposites were successfully prepared by in situ polymerization of pyrrole in the presence of NanoGs. The morphology and stability of the materials were characterized by scanning electron microscope and thermogravimetric analysis. Electrical conductivity and mechanical properties of the composites were also investigated. The results showed that the NanoGs-PPy/epoxy composites not only maintained its good electrical conductivity but also keep favorable mechanical properties.
TL;DR: The synthesis and spectral characterization of mononuclear cephalosporin tin(II) complexes of general formula [Sn(L)Cl] indicate that the antibiotics act as multidentate ligand toward metal ions, via the amide and lactam carbonyl and carboxylate and N-azomoieties.
Abstract: The synthesis and spectral characterization of mononuclear cephalosporin tin(II) complexes of general formula [Sn(L)Cl] (L = monoanion of cephalothin HL1, cephradine HL2, cefotaxime HL3, cefazolin HL4, and ceftriaxone HL5), are reported They were characterized by physicochemical and spectroscopic methods The spectra indicated that the antibiotics act as multidentate ligand toward metal ions, via the amide and lactam carbonyl and carboxylate and N-azomoieties The complexes are nontoxic, insoluble in water, and common organic solvents and probably have polymeric structures The ligands and their tin complexes have been screened for their antibacterial activities and found to be quite active in this respect Coordination of cephalothin and cephradine to tin(II) ion showed an enhancement of the antibacterial activity
TL;DR: In this paper, a sol-gel synthesis of an inorganic mesostructured composite photocatalyst for application in water purification is discussed, and the fundamentals for each synthesis step on the final Ti-content, anatase-to-rutile composition, bonding structure and mechanism to kaolinite, shape, surface area, and size control are described.
Abstract: The paper discusses the sol-gel synthesis of an inorganic mesostructured composite photocatalyst for application in water purification. The fundamentals for each synthesis step on the final Ti-content, anatase-to-rutile composition, bonding structure and mechanism to kaolinite, shape, surface area, and size control were described. In addition, various advanced microscopic techniques were used to characterize and validate the physical and chemical properties of the composite photocatalyst. A hypothetical schematic for the fabrication of mesostructured composite photocatalyst was also presented to better illustrate the overall reaction and binding mechanism. The photocatalytic degradation of an aqueous dye solution was also investigated.
TL;DR: In this paper, a dioxomolybdenum(VI) complex, [MoO2L(CH3OH)]· CH3OH, where L is the dianionic form of N’-[1-(2-hydroxyna-phthyl)ethylidene]-3-methylbenzohydrazide, was prepared and structurally characterized by physicochemical and spectroscopic methods and single crystal X-ray determination.
Abstract: A new dioxomolybdenum(VI) complex, [MoO2L(CH3OH)]· CH3OH, where L is the dianionic form of N’-[1-(2-hydroxyna- phthyl)ethylidene]-3-methylbenzohydrazide, was prepared and structurally characterized by physicochemical and spectroscopic methods and single crystal X-ray determination. The complex is a mononuclear molybdenum compound. The Mo atom is in octahedral coordination. The catalytic property of the complex indicates that it is an effective catalyst for sulfoxidation.
TL;DR: In this paper, a facile procedure for size-controlled synthesis of gold nanoparticles based on the reduction of Au3+ (HAuCl4) using Preyssler heteropolyacid (H14[NaP5W30O110]) under UV irradiation was described.
Abstract: The authors describe a facile procedure for size-controlled synthesis of gold nanoparticles based on the reduction of Au3+ (HAuCl4) using Preyssler heteropolyacid (H14[NaP5W30O110]) under UV irradiation. Preyssler plays the role of green reducing agent and also efficient stabilizer. This method allows the synthesis of uniform hexagonal nanoparticles with an average size that is tunable between 1.35 and 86.7 nm by varying the gold ion concentration, molar ratio of gold ion to Preyssler, and Propan-2-ol amount. The authors found that there is a critical ratio for [Au3+]/[Preyssler] in which two opposing trends in the size of nanoparticles would happened.
TL;DR: Two new mononuclear Schiff base zinc(II) complexes with the formula [ZnXL]·BF4 [X = Cl for (1) and X = Br for (2); L = N,N′-bis(1-pyridin-2-ylethylidene)propane-1,2-diamine] have been prepared.
Abstract: Two new mononuclear Schiff base zinc(II) complexes with the formula [ZnXL]·BF4 [X = Cl for (1) and X = Br for (2); L = N,N′-bis(1-pyridin-2-ylethylidene)propane-1,2-diamine] have been prepared. The complexes have been characterized by physicochemical methods and single-crystal X-ray determination. Each compound contains a mononuclear zinc(II) complex cation and a disordered fluoroborate anion. The zinc(II) atoms in both complexes are five-coordinated by the four N atoms of L, and by one halide atom, forming a square-pyramidal coordination. The Schiff base ligand and the zinc(II) complexes showed potent antibacterial activities.
TL;DR: In this paper, the surface of pristine Fe3O4 nanoparticles is modified with a silane coupling agent methacryloxypropyltrimethoxysilane (MPTMS), which provides a reactive C = C bond to copolymerize with acrylic acid (AA) by in situ polymerization in scCO2, resulting in the formation of covalently bonded PAA-Fe 3O4 nanocomposite.
Abstract: The surface of pristine Fe3O4 nanoparticles is first modified with a silane coupling agent methacryloxypropyltrimethoxysilane (MPTMS), which provides a reactive C = C bond to copolymerize with acrylic acid (AA) by in situ polymerization in scCO2, resulting in the formation of covalently bonded PAA–Fe3O4 nanocomposite. The as-synthesized products were characterized using FT-IR, TGA, XRD, SEM, TEM, and XPS. The results indicated that the obtained nanocomposite had a core-shell structure, in which the Fe3O4 nanoparticle cores were coated completely with PAA shells. The adsorption of methylene blue onto the obtained nanocomposite increased with increasing solution pH.
TL;DR: In this paper, the pore size distribution with average, minimum, and maximum pore diameter of nanoporous anodic aluminum oxide (AAO) membranes were fabricated by a two-step anodization process using scanning electron microscopy images of the fabricated anodized alumina.
Abstract: Nanoporous anodic aluminum oxide (AAO) membranes were fabricated by a two-step anodization process Quantitative structural characterization was carried out using scanning electron microscopy images of the fabricated anodized alumina An algorithm based on mathematical morphology was developed to extract pore size distribution with average, minimum, and maximum pore diameter of the nanoporous alumina This technique of obtaining quantitative data based on image analysis could be an efficient, unbiased, and reliable method and can be used to control the fabrication parameters of anodization process
TL;DR: In this paper, a novel lanthanide complexes with the general formula [Ln(L)(ONO2)(H2O)2] have been synthesized and characterized, and thermal, magnetic, molar conductance, and spectral studies confirm that the ligand coordinates through sulfur, azomethine nitrogen, and phenolic oxygen.
Abstract: Novel lanthanide complexes with the general formula [Ln(L)(ONO2)(H2O)2] have been synthesized and characterized. {L = 5-bromosalicylidene 4-amino 3-mercapto-1,2,4-triazine-5-one (BrSAMT), Ln = La(III), Ce(III), (Pr(III) Eu(III), Sm(III), Nd(III), Tb(III), Dy(III), and Y(III)}. The thermal, magnetic, molar conductance, and spectral studies confirm that the ligand coordinates through sulfur, azomethine nitrogen, and phenolic oxygen. A scheme of thermal decomposition of the complexes is also proposed. La, Eu, and Yb complexes of BrSAMT show antibacterial activity against gram negative bacteria such as E. coli, Pseudomonas aeruginosa, Salmonella typhi, and Shigella flexneri.
TL;DR: In this article, the authors retracted a retracted article which they termed as "untruthful" and "misrepresented" the authors' intentions. But this article has been retracted.
Abstract: This article has been retracted
TL;DR: In this article, three mononuclear cobalt(II) complexes, [Co(H2MOPhIDC)2 (H2O)2]·2H 2O (H3MOPHIDC = 2-(3-methoxyphenyl)-1H-imida-zole-4,5-dicarboxylic acid) (1), [Co[H2MoPhIDc)2(H 2 O]· 2CH3CN (2), and [Co
Abstract: Three mononuclear cobalt(II) complexes, [Co(H2MOPhIDC)2 (H2O)2]·2H2O (H3MOPhIDC = 2-(3-methoxyphenyl)-1H-imida- zole-4,5-dicarboxylic acid) (1), [Co(H2MOPhIDC)2(H2O)2]· 2CH3CN (2), and [Co(H2PhIDC)2(H2O)] (3) (H3PhIDC = 2-phenyl-1H-imidazole-4,5-dicarboxylic acid), have been hydro(solvo)thermally synthesized by fine control over synthetic conditions such as solvent, pH value, and temperature. Their molecular structures have been characterized by IR spectra, elemental analyses, and thermogravimetric analyses and further characterized by single-crystal X-ray diffraction. Furthermore, the photoluminescent properties of the three complexes have been investigated.