Structural and magnetic properties of Ni/Pt multilayers

In this work, the variation of the magnetic moments of the Ni/Pt multilayers are studied using the linearized augmented plane waves (LAPW) method in the framework of the density functional theory (DFT) implemented in the version of WIEN2K program. The systems have been modeled by seven layers slab separated in z direction by a vacuum region of four substrate layers. We present the results of the dependence of the magnetic properties with respect to the thickness variation of the different multilayers. The modeling of these systems finds an important empirical support. Experiment and theory show the same trends for the magnetic moments: hybridization effects between Ni and Pt are mostly localized at the interface.     

Measurement of surface topography by RGB Shadow-Moiré with direct phase demodulation

In this paper we present the application of a direct demodulation method for the measurement of surface topography by means of Shadow-Moiré. In our set-up, we use three LEDs (with green, red and blue peak wavelengths) to illuminate the grating. Due to the different position of these light sources, a polychromatic Shadow-Moiré fringe pattern is produced, which can be described as the superposition of three monochromatic (red, green and blue) fringe patterns. Taking the image of this polychromatic fringe pattern with a RGB CCD camera, we get a monochromatic fringe pattern stored at each RGB channel of the CCD. The direct demodulation algorithm employed uses these fringe patterns to calculate the wrapped phase map. After unwrapping the phase map using a standard multi-grid technique, we implemented an automatic procedure to detect the area of interest of the phase map by removing low modulation zones and to calculate the absolute value of the phase. In this way it is possible to determine the topography of a surface with a single RGB snapshot maintaining a simple experimental set-up, which is an important feature, especially for the study of dynamic phenomena such as deformations. We present the experimental results obtained after measuring different objects with both smooth and rough surface textures.     

3‐(3‐Oxo‐1,3‐dihydroisobenzofuran‐1‐ylidene)pentane‐2,4‐dione

In the title compound, C₁₃H₁₀O₄, prepared by the condensation reaction between phthalic anhydride and pentane‐2,4‐dione, one of the acetyl groups in the pentane‐2,4‐dione fragment is almost coplanar with the isobenzofuran ring system, while the other group is twisted out of this plane by almost 80°. The corresponding C—C and C—O distances in the two acetyl units are consistent with dipolar delocalization into the coplanar unit only. There is no supramolecular aggregation of the molecules, but a number of rather short intermolecular contacts of C—H...O, O...O and O...C types occur.     

Synthesis of 2-(p-R-benzoylmethylene)-3-(p-R-phenyl)-1H-quinoxalines

The reaction of 1,2-diaminobenzenes with substituted 1,2-dibenzoyl-1,2-dibromoethanes constitutes a convenient synthetic route to the hitherto 2-(p-R-benzoylmethylene)-3-(p-R-phenyl)-1H-quinoxalines. Structures of all products were elucidated by ir, ¹H and ¹³C-nmr, mass spectra data. X-Ray crystallography data confirm assigned structures.     

A novel synthesis of thiazoles from dimethyl N-(ethoxycarbonylmethyl)imino dithiocarbonate, carbon disulfide and alkyl halides.

We report a new synthesis of thiazoles from a cyclocondensation reaction between dimethyl N-(ethoxycarbonylmethyl)iminodithiocarbonate (EMIC), carbon disulfide and alkylation of intermediate thiazole-2-thiolate with alkyl halides.     

Solvent‐free microwave synthesis of bis‐pyrazolo[3,4‐b:4′,3′‐e]‐pyridines and study of their antifungal properties

The synthesis of a series of bis‐pyrazolo[3,4‐b:4′,3′‐e]pyridines ( 3 ) in the reaction of 5‐amino‐3‐methyl‐1‐phenylpyrazole ( 1 ) with aldehydes ( 2 ) under microwave irradiation and solvent‐free conditions is described. The structure elucidation of the products is based on detailed nmr analysis of experiments such as ¹H‐COSY, NOESY, DEPT, HSQC and HMBC. These compounds showed moderate antifungal in vitro activity against dermatophytes.     

Microdetermination of iodine in carrier-free131I solutions

A photocolorimetric microtechnique is described, by which it is possible to determine the real amount of iodine in carrier-free solutions of¹³¹INa. The method is conceptually based on the well-known effect of iodine, by which the rate of reduction of ceric sulfate by arsenious acid in sulfuric acid solutions is proportional to the iodide concentration. The tittration and the preparation of its corresponding calibration graph require approximately 90 min; thus, it seems possible to use this technique as a routine analysis. Under the stated conditions of temperature and reaction time, it is possible to determine samples of iodine with concentrations ranging between 20 and 160 ng/ml. The standard error between different determinations is less than ±5%. The application of the method in production control and utilization of carrier-free¹³¹I solutions, free from reducing agent, are discussed.     

The reaction of aromatic α,β-unsaturated ketones with 4,5-diamino-1,6-dihydropyrimidin-6-ones

The reaction of 4,5-diamino-1,6-dihydropyrimidin-6-ones 1 with one equivalent of the chalcones 2 leads in an acidic medium to the formation of the 2,4-diaryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b][1,4]diazepin-6-ones 3a-m . The structure elucidation of the products is based on detailed nmr investigations including selective ¹³C[¹H] decoupling experiments.     

Synthesis of 4-aryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b][1,4]-diazepin-6-ones from 4,5-diamino-1H-pyrimidin-6-ones and 1-aryl-3-(dimethylamino)-1-propanones

The reaction of 1-aryl-3-(dimethylamino)-1-propanones 1 with one equivalent of 4,5-diamino-1H-pyrimidin-6-ones 2 , in acidic medium, leads to the formation of 4-aryl-2,3,6,7-tetrahydro-1H-pyrimido[4,5-b]-[1,4]diazepin-6-ones 3 . The structure elucidation of the products is based on detail nmr analysis of experiments such as ¹³C, ¹H and DEPT including selective ¹³C{¹H} decoupling experiments.