Reactivity of Tetrakis(4-tert-butyl-5-phenylsulfanyl)­phthalocyanine in Acid–Base Interactions with Organic Bases

Russian Journal of Organic Chemistry - Study of the acid–base interaction of tetrakis(4-tert-butyl-5-phenylsulfanyl)phthalocyanine with cyclic and acyclic nitrogen bases in benzene and...     

Atom States and Interatomic Interactions in Complex Perovskite-Like Oxides: XV.1 Magnetic Susceptibility of La0.67Ca0.33MnO3-LaAlO3 Solid Solutions

Magnetic susceptibility of diluted solid solutions of manganites with perovskite structure having a colossal magnetoresistivity was studied. It was found that the systems are characterized by ferromagnetic type strong exchange interactions, which are characterized by an exchange parameter varying with temperature.     

Catalytic properties and phase composition of multicomponent catalysts for oxidative ammonolysis of propane

Studies of the phase composition and catalytic properties of several complex oxide catalysts for oxidative ammonolysis of propane indicate that the active phases of these catalysts are antimonates of the respective metals. Phosphorus and tungsten additives to the catalysts promote the formation of such phase compositions, i.e. the formation of antimonates and the binding of excess antimony oxide.

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Comparative characterization of two techniques for selenium(IV) preconcentration on a film mercury electrode with the use of an automated solution replacement system without circuit disconnection

Two versions of selenium(IV) preconcentration and determination on a mercury film electrode (MFE) by cathode stripping voltammetry with an automated solution replacement system without circuit disconnection are compared. In one version, selenium(IV) is preconcentrated together with copper(II); in the other, selenium is preconcentrated on a copper-modified MFE. Under optimum conditions (against the 0.1 M HCl background at selenium electrolysis potentials from ?350 to ?400 mV and electrolysis times of 180–300 s), calibration curves for both selenium preconcentration versions are linear over the concentration ranges from 2.5 to 20 μg/L and from 50 to 250 mg/L. The selenium peak heights are well reproduced in both cases (in the range of the concentrations studied, S _r lie in the range from 0.02 to 0.05). Sequential copper and selenium preconcentration is more convenient: there is no need to add copper to each analyzed solution, and it is possible to optimize selenium preconcentration parameters (solution composition, electrolysis potential, and electrolysis time) regardless of the copper preconcentration parameters.     

Determination of the thermodynamic activity of sulfuric acid in the H2SO4-H2O-HCHO system by an indicator method

The ionization of N,N-dimethyl-2,4-dinitroaniline in water-formaldehyde solutions of H₂SO₄ consists in the addition of a H₂SO₄ molecule to an indicator molecule. The logarithm of the indicator ratio for identical molality of the acid in a water-formaldehyde solution and in water varies linearly as a function of the logarithm of the thermodynamic activity of the acid for a molar ratio of free water to methylene glycol >-10. A method is presented for calculation of the thermodynamic activity of the acid in the H₂SO₄,-H₂O-methylene glycol system in the H₂SO₄, molality range from 1 to 4 for the given molar ratio of free water to methylene glycol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 987–991, May, 1990.     

NMR study of the spatial structure of synthetic pyrethroids

The spatial isomers of the new synthetic analogs of ethyl permithrinic ether and permethrin were investigated by NMR (¹H, ¹³C, DEPT (distortionless enhancement by polarization transfer), COSY (correlation spectroscopy), CHCORR (heteronuclear (C, H) shift correlation spectroscopy), ROESY (rotating-frame Overhauser effect spectroscopy)). Several tendencies were revealed in the ¹H and ¹³C chemical shifts of the α atoms of the substituents in the 2nd and 3rd positions of the cyclopropane ring. For substituents cis-orientated relative to the ester group, the spectra show a paramagnetic shift of the ¹H signals and the diamagnetic shift of the ¹³C signals relative to the trans-orientated substituents. The ¹H and ¹³C chemical shifts of the α atoms of the substituents in the 2nd and 3rd positions of the cyclopropane ring permit an unambiguous determination of the stereochemistry of ethyl permethrinic ether and permethrin analogs.     

Mean Parameters of an Incompressible Turbulent Boundary Layer on the Wind Tunnel Wall at Very High Reynolds Numbers

Flow, Turbulence and Combustion - The mean parameters of a two-dimensional incompressible turbulent boundary layer with zero pressure gradient were measured on the smooth wall of the TsAGI T-128...     

Kinetics of Proton Transfer from Octa(m-trifluoromethylphenyl)porphyrazine to Nitrogen-Containing Bases in the Benzene–Dimethylsulfoxide System

Russian Journal of Physical Chemistry A - The acid–base interaction between octa(m-trifluoromethylphenyl)porphyrazine and pyridine, 2‑methylpyridine, morpholine, and piperidine in the...     

Kinetics and mechanism of hydration of 3-methyl-3-buten-1-ol in aqueous solutions of sulfuric acid

Conclusions The kinetic regularities of hydration of 3-methyl-3-buten-1-ol in 9.6 to 34% aqueous solutions of sulfuric acid at 25°C were studied. An equation was found for describing the influence of the medium on the value of the effective rate constant of hydration of 3-methyl-3-buten-1-ol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1016–1019, May, 1988.