Textured nickel tapes prepared from commercially available material

Textured Ni tapes were fabricated from commercially available nickel pellets (98.5% Ni). Ingots produced by a melt process were cold rolled to 150–400 μm thick tapes. Texturing was achieved by annealing in a reducing atmosphere (Ar + 6.5% v/v H₂). Sharp cubic biaxial textured Ni tapes were obtained by thermal treatment at 1000°C for 2 hours in a reducing atmosphere. The tapes were characterized by scanning electron microscopy, X-ray diffraction and by electron backscattering diffraction. The tensile strength, the thermal expansion behavior and the Vickers hardness for the cold rolled tapes and for the heat-treated tapes were measured.      

Calorimetric study of melts in the System KF - K<Subscript>2</Subscript>NbF<Subscript>7</Subscript>

The relative enthalpies of melts in the system KF - K₂NbF₇ were measured by drop-calorimetry at the temperatures 1058, 1140 and 1208 K as a function of composition. Heat capacities of melted mixtures and enthalpies of mixing were determined using the experimental data. The molar heat capacity of melts diverges slightly from additivity. The molar enthalpy of mixing of melts shows small negative deviation from ideality which decreases with decreasing temperature. The thermal effect at mixing was assigned predominantly to association reactions producing more complex fluoroniobate anions.      

Ionic liquid promoted synthesis of bis(indolyl) methanes

1-benzyl-3-methyl imidazolium hydrogen sulphate [bnmim][HSO₄] was found to be an effective catalyst for the condensation reaction of indoles and derivatives with benzaldehydes in microwave irradiation with lower reaction time and higher yields to give bis(indolyl) methanes.      

Ugi products containing boronate esters

The Ugi reaction with formylphenylboronic acid derivatives as the carbonyl component proceeds to give the corresponding boron-containing dipeptide derivatives (Ugi products) in good yields.      

2-pyrrolidone - capped Mn<Subscript>3</Subscript>O<Subscript>4</Subscript> nanocrystals

Water-soluble Mn₃O₄ nanocrystals have been prepared through thermal decomposition in a high temperature boiling solvent, 2-pyrrolidone. The final product was characterized with XRD, SEM, TEM, FTIR and Zeta Potential measurements. Average crystallite size was calculated as ∼15 nm using XRD peak broadening. TEM analysis revealed spherical nanoparticles with an average diameter of 14±0.4 nm. FTIR analysis indicated that 2-pyrrolidone coordinates with the Mn₃O₄ nanocrystals only via O from the carbonyl group, thus confining their growth and protecting their surfaces from interaction with neighboring particles.      

Efficient synthesis of diarylidene octahydroacridines by one-pot multi-component tandem reactions

A one-pot multi-component reaction is developed for the efficient synthesis of 4,5-dibenzylidene octahydroacridines in high yields. The reaction is performed by the tandem reaction of three molar equivalent aromatic aldehydes with two molar equivalent 4-alkylcyclohexanone in the system of NH₄OAc/HOAc under microwave irradiation.      

Extraction of acyclovir from pharmaceutical creams for HPLC assay. Optimization and validation of pretreatment protocols

Three simple protocols for the extraction of acyclovir from its pharmaceutical creams based on ultrasonication, ultrasonication with heating and magnetic stirring were evaluated and compared. Extraction kinetics were studied at different time intervals (5, 10, 15, 30 and 60 min) and the extraction efficiency was determined by HPLC. The effect of concentration of aqueous NaOH as the extraction medium and the stirring speed were also studied and optimized. Best results were obtained with 50 mL of 0.01 mol L⁻¹ aqueous NaOH with magnetic stirring speed of 500 r.p.m. HPLC analysis involved rapid separation of acyclovir from the cream matrix using a 100 × 4.6 mm i.d. monolithic column and UV detection at 254 nm. Magnetic stirring produced the best results in terms of extraction efficiency with an average extraction yield of 100.8%, n = 16 at an optimum extraction time of 15 min. The selected protocol was validated for within and day-to-day precision and ruggedness.      

Bi(NO3)3 · 5H2O mediated synthesis of 4,4′-diaminotriarylmethane leuco malachite compounds under solvent-free conditions

In this report, we described the synthesis and characterization of a variety of diaminotriarylmethane derivatives with dimethylamino functional groups. These compounds were synthesized by the tandem regio-selective electrophilic aromatic substitution reaction of N,N-dimethylaniline with aryl aldehydes to form the corresponding diaminotriarylmethane compounds. In our strategy, Bi(NO₃)₃ was used as a catalyst under solvent free conditions to afford the desired products in good to excellent yields.      

Electrical and optical properties of a single Sb2Se3 nanorod

In this paper we present the methods to chemically synthesize the Sb₂Se₃ nanorods and study the electrical and optical properties of a single Sb₂Se₃ nanorod with an average size of 70 nm in diameter and a length of about 1 μm to 2 μm. The techniques we devised can immobilize and allocate a single nano-object on an electron beam (E-beam) patterned smart substrate. It can also overcome the limitation of the spatial resolution of conventional optical techniques (∼ 1 mm) to obtain optical spectroscopy in an individual nano-object less than 100 nm in size. We also demonstrate the techniques in using E-beam defined metallic coordination markers as electrodes to measure the conductance of a single Sb₂Se₃ nanorod.      

Synthesis of SnO<Subscript>2</Subscript> nanopowders by a sol-gel process using propanol-isopropanol mixture

A simple sol-gel process is proposed for synthesizing SnO₂ nanopowders utilizing normal propanol and isopropanol mixture instead of just using normal alcohols such as ethanol, propanol or butanol for Sol preparation. No surfactant was used in this Sol preparation process. The structure of sol is studied by FT-IR-ATR technique. On altering propanol to isopropanol ratio, three different nanopowders were obtained. X-ray powder diffraction, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction pattern (SAED) and BET techniques were used to characterize prepared powders. Results show that smaller grain size was obtained via altering alcohols ratio. In addition, Merck commercial SnO₂ powder was also used as a reference material for comparing purposes; because it has nanometer scale (ca. 60 nm). HRTEM images show that obtained nanopowders were polycrystalline and their average diameters fall into the range of 6–80 nm. Finally, the effect of alkoxide ligand size through sol-gel synthesis on product particle size is discussed.      

Synthesis and structure of new 3,7,10-substituted-phenothiazine derivatives

The synthesis of new 3,7-dibromophenothiazine derivatives bearing bromoalkyl, mercaptoalkyl and alkylthioacetate groups on the N atom at position 10 is reported. The Suzuki coupling reaction of one of these derivatives via the bromine atoms at positions 3 and 7 with bromothiophene derivatives is also discussed.      

Colour change of co-doped yttrium aluminium borate crystals under illumination with different white light sources

A colour change of doped YAB crystals and microcrystalline powders takes place upon illumination with different white light sources. This paper presents extensive experimental data on the new materials Ho,Nd:YAB; Ho,Cr:YAB, Nd,Cr:YAB and Ho,Nd,Cr:YAB, resulting in a chart providing the observed crystal colours and chromaticity differences of the materials under illumination with seven different types of white light sources. The microcrystalline powders could be used as coatings in order to produce a special colour changing effect. Furthermore, the colour table presented enables the observer to discriminate the investigated light sources at one glance.      

Synthesis of Xenbucin using Suzuki reaction catalyzed by Pd/C in water

Xenbucin 1, an analgesic drug, was synthesized in 4 steps using two different routes. The biaryl fragment could successfully be produced via a Pd/C catalysed Suzuki coupling in water using sodium tetraphenylborate as a phenylation reagent. Overall yields of the routes were 36% and 59%, respectively.      

Synthesis,characterization and antifungal testing of 3,4-dihydropyrimidin-2(1H)-(thio)ones containing boronic acids and boronate esters

The addition of formylphenylboronic acid derivatives to thiourea and ethyl acetoacetate proceeds in the presence of an additional Lewis acid catalyst to give the corresponding 3,4-dihydropyrimidin-2(1H)-(thio)ones (Biginelli products) in moderate yield. Compounds were tested for antifungal activity against pure cultures of Aspergillus niger, Aspergillus flavus, Candida albicans and Saccharomyces cerevisiae but, unfortunately, none showed any appreciable activity.      

Preliminary results of a quick,simple method of detecting antimony in water samples

Preliminary results of development of a direct and fast method of determination of antimony in samples of tap water using GFAAS are presented. The found levels of antimony were lower than permitted for human consumption. A mixture of Pd and Mg(NO₃)₂ (concentrations in the injected solution: 8.6 μg mL⁻¹ and 5.8 μg mL⁻¹ respectively) was used as the chemical modifier. The pyrolysis and atomization temperatures were 1000 and 1700°C, respectively and the mean analytical recovery 98.2%.      

The binary system PbO - BiVO4

Phase equilibria established in the PbO - BiVO₄ system over the whole component concentration range up to 1000°C have been investigated. A phase diagram has been constructed using DTA and XRD.      

Microwave-induced combustion synthesis and characterization of NixCo1−xFe2O4 nanocrystals (x = 0.0, 0.4, 0.6, 0.8, 1.0)

A series of Ni-doped cobalt ferrites Ni_xCo1_−xFe₂O₄ (x = 0.0, 0.4, 0.6, 0.8, and 1.0) were prepared using microwave-induced combustion. Nickel, cobalt, and ferric nitrates were used as starting materials and glycine as fuel. The influence of Ni content on the lattice parameter, stretching vibrations, and magnetization was studied. XRD, FTIR, and SEM were used for structure, composition, and morphology investigation. A porous network structure was observed with average particle size 60–67 nm. All samples had a cubic spinel structure. The unit cell parameter “a” decreases linearly with nickel concentration due to the smaller ionic radius of nickel. Magnetization measurements showed that coercivity decreased as Ni content increased; it increased with decreasing temperature.      

Synthesis by self-assembly and structural characterization of a new co-crystal system {[Cu(NO3)2(H2O)2]L1(NO3)2} (L1 = 1,1′-dibenzyl-3,3′-butyl-diimidazolium-2,2′-diylidene) from copper nitrate and a carbene precursor

Herein, the first example of a co-crystal system formed by an imidazolium nitrate, a carbene precursor, and copper (II) nitrate, {[Cu(NO₃)₂(H₂O)₂]L1(NO₃)₂} (1) (L1 = 1,1′-dibenzyl-3,3′-butyl-diimidazolium-2,2′-diylidene) is reported. These two building blocks are connected in the solid state through hydrogen bonds to generate a three-dimensional supramolecular network.      

The effect of substituents of immobilized Rh complexes on the asymmetric hydrogenation of acetophenone derivatives

Using a modified Augustine’s method variously substituted Rh complexes were anchored on Al₂O₃ support. The prepared catalysts were characterized by spectroscopic methods and were applied in the hydrogenation of several acetophenone derivatives (p-CF₃-acetophenone, acetophenone, p-NH₂-acetophenone). Enantioselective C=O hydrogenations were observed with reasonable activity and selectivity on all heterogenized complexes, e.e. up to 80%. At the same time the immobilized samples showed the advantages of the heterogeneous systems: easy handling and recyclability.      

2-(benzimidazol-2-yl)-3-hydroxychromone derivatives: spectroscopic properties and a possibile alternative intramolecular proton phototransfer

Three 2-(benzimidazol-2-yl)-3-hydroxychromone derivatives were synthesized. Their spectroscopic and fluorescent properties, due to excited state intramolecular proton transfer (ESIPT) from OH to carbonyl, were studied. Theoretical possibility of an alternative intramolecular H-bonding and experimental evidence for such behavior are discussed.