Mass-spectral behavior of 2-azatriptycene and its derivatives

The mass-spectral behavior of 11 aromatic and partially hydrogenated 2-azatriptycenes was investigated. It was established that the principal fragmentation pathway for these compounds is the formation of [M-nH] ⁺ and [M-nH]²⁺ ions (n = 1–6), as well as pseudoretrodiene fragmentation of the heterocyclic ring with the elimination of the atoms in the 2 and 3 positions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1399–1402, October, 1981.     

Omega chrome black blue G as a colorimetric reagent for the microdetermination of various cations

Summary Omega Chrome Black Blue G has been found to be a suitable colorimetric reagent for the detection of cobalt and for the determination of copper, cobalt, cadmium, lead and magnesium. The effects of time, p_H, temperature, and foreign ions on the absorbancy are investigated. The reagent is practically suitable for the determination of microgram amounts of cobalt in presence of nickel and other ions which evoke a red colour.The reagent is not suitable for the determination of nickel, calcium, strontium, and zinc.     

Electric and dielectric properties of some gamma-irradiated cabal glasses

Electrical conductivity and dielectric properties have been studied for the glass system CaO---B₂O₃---Al₂O₃ in the temperature range 40–200°C. The substitution of 5% B₂O₃ by CaO or replacing 5% CaO by Na₂O or MgO cause a decrease in the conductivity, but the decrease obtained by soda is greater than that of magnesia. The activation energies of the tested glasses were calculated. All the glasses investigated showed a dielectric constant almost independent of temperature at fixed frequency. The effect of subjecting the glass to a constant dose of gamma-rays changes both the electrical conductivity and dielectric constant. The experimental results were discussed in relation to the specific conduction mechanism in such glasses. Also the effect of varying glass composition or temperature on the mobility or migration of current carrier was considered. The possible creation of induced defects in glass on irradiation was evaluated.     

Radioiodination of N-[3-(4-morphilino)propyl]-N-methyl-2-hydroxy-5-iodo-3-methyl-benzylamine (ERC9) via isotopic exchange reaction

Summary A simple method for labeling ERC9 with radioactive iodine has been carried out via nucleophilic substitution radioiodination. The factors affecting the radiochemical yield of the labeling of ERC9, such as pH of the medium, substrate concentration and temperature were investigated. Chromatographic analysis technique was used to determine the radiochemical yield and purity. Kinetics and thermodynamic parameters indicated a second order reaction. Activation energy for the isotopic exchange reaction between ERC9 and ¹²⁵I^- was calculated to be 24.4 kJ/mol.     

Experimental study of the A0 and S0 Lamb waves interaction with symmetrical notches

The aim of this work is to study the fundamental Lamb modes interaction with defects in isotropic plates. For these experimental investigations, symmetrical notches with various depths milled in aluminum plates are considered. Moreover, the incident Lamb wave of a specific mode is generated by means of two identical thin piezoceramic transducers placed at the opposite sides of the plate. The waves scattered by the notch are recorded with conventional transducers located on the plate surface in front and behind the defect. The selection of the A₀ or the S₀ modes is obtained by exciting the transducers with anti-phased or in-phased signals, respectively. Furthermore, a calibration process is investigated to correct errors caused by the presence of the receiver between the emitters and the defects. The power reflection and transmission coefficients are then obtained and the power balance is verified. Finally, these measurements are compared successfully with those obtained by a numerical method using the finite-element modeling described in a previous work.     

Eriochrome black A as reagent for spectrophotometric microdetermination of cobalt in presence of nickel

Summary Eriochrome black A has been found to be a suitable reagent for the spectrophotometric determination of microgram quantities of cobalt in pure cobalt solutions and in the presence of nickel and some other cations by measuring the decrease in the absorbance of Eriochrome black A at p_H 10, caused by the presence of cobalt.Many foreign cations especially nickel were completely masked by EDTA. Amounts as low as about 0.9 to 3 g were determined with fair accuracy.     

Angular correlation measurements in the Be9(d,p, γ)Be10 reaction

Thep-γ angular correlations in the Be⁹(d, p, γ)Be¹⁰ reaction have been measured in the reaction plane atE _d =1.3, 1.5, 1.9, 2.3 and 2.45 MeV for proton anglesθ _p =35°, 80° and 120°. The anisotropy of the angular correlations measured forθ _p =35° is independent of deuteron energy. A systematic shift of the symmetry axis from the recoil direction has been observed. The shift is 20.5° at E_d=2.45 MeV. The anisotropy decreases with increasing proton angle and vanishes atθ _p =120°.     

Reaction of acetylenic ketones with hydrazine derivatives. Synthesis of hydroxypyrazoles

Aroylphenylacetylenes Ia-c react with (-butyl hydrazinecarboxylate (IIa) and 2-furylhydrazide (IIb) to give the corresponding hydroxydihydropyrazole derivatives IVa-f. This cyclic structure is supported by chemical transformations. Thus, when compounds IVa-c are heated with acetic anhydride, they yield the corresponding 5-aryl-1-(t-butoxycarbonyl)-3-phenylpyrazoles Va-c which, upon hydrolysis with methanolic potassium hydroxide, produce the corresponding 5(3)aryl-3(5)phenylpyrazoles VI. Spectroscopic data also confirm the suggested cyclic structure IV.     

Convenient Methodology for Some Heterocyclization Reactions with Thioxopyrimidine Derivatives

Russian Journal of Organic Chemistry - A simple and efficient method for derivatization of the pyrimidine nucleus is developed. The readily available 6-amino-2-thioxo-2,3-dihydropyrimidin-4(1H)-one...