Reaction in the system trialkyl phosphite-carboxamide or secondary amine

Conclusions A study was made of reaction in the system: triethyl phosphite-amide (amine)-paraform(benzaldehyde). The reaction leads to the formation of the corresponding esters of aminomethyl(alkyl)phosphonic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2773–2776, December, 1971.     

Kinetics of the reaction of triethylphosphite with β-acetoxyethylmethyl ketone

Conclusions The kinetics of the reaction of triethylphosphite with-acetoxyethylmethyl ketone was studied by infrared spectroscopy, and was found to be of the second order.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2614–2616, November, 1968.     

Photolysis of 3-(1-acyl-5-aryl-3-pyrazolinyl)coumarins—Effective Fluorescence Decay

Photophysical characteristics of new 3-(1-acyl-5-aryl-3-pyrazolinyl)coumarins have been measured. These coumarin derivatives are found to be effective fluorophores and show high values of quantum yields of fluorescence both in nonpolar and in polar solvents. The 3-(1-acyl-5-aryl-3-pyrazolinyl)coumarins turned to be photosensitive compounds and undergo photolysis under irradiation in the range of 310–465 nm. Photolysis is suggested to include retro-cyclization and retro-condensation steps. The process is accompanied by a sharp drop of fluorescence that can be of interest for the creation of new media in optical recording of information.     

Contribution of LHC II complex to the electric properties of thylakoid membranes: an electric light scattering study of Chl b-less barley mutant

Electric light scattering measurements demonstrate a strong decline in the permanent electric dipole moment and electric polarizability of both thylakoid membranes and photosystem II-enriched particles of the Chlorina f2 mutant which has severely reduced levels of light-harvesting chlorophyll a/b-binding proteins compared to the wild type barley chloroplasts. The shift in the electric polarizability relaxation to higher frequencies in thylakoids and photosystem II particles from Chlorina f2 reflects higher mobility of the interfacial charges of the mutant than that of the wild type membranes. The experimental data strongly suggest that the major light-harvesting complex of photosystem II directly contribute to the electric properties of thylakoid membranes.     

Chromaticity characteristics of binary and ternary molybdenum(vi) complexes with o,o’-Dihydroxyazo and heterocyclic azo compounds

The chromaticity characteristics of molybdenum(VI) complexes with o.o’-dihydroxyazo compounds (Lyumogallion IREA and Magnezon IREA) and heterocyclic azo compounds [4-(2-pyridylazo)resorcinol and 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol] were studied in the presence and in the absence of the third component, hydroxylamine. It was demonstrated that chromaticity characteristics can be used for analyzing samples with low molybdenum concentrations. The calibration graph equations for the color characteristics of complexes both in solution and in the immobilized exhibit sensitivity coefficients more than an order of magnitude higher than for absorbance and the Kubelka-Munk function     

Electrochemical behavior of electrode modified with a cobalt hexacyanoferrate film: Effect of the supporting electrolyte cation

Cobalt hexacyanoferrate films are synthesized on a glassy carbon electrode with sodium, potassium, and ammonium salts in the supporting electrolyte. The electrochemical behavior of the modified electrode is studied in individual solutions of the salts and in their mixtures. The change in electrochemical properties of cobalt hexacyanoferrate agrees with an increase in the interaction of cations with the film in the series Li⁺, Na⁺, K⁺, NH ₄ ⁺ , Cs⁺. The effect of the energy of interaction between the modify ing-substance crystal lattice and counter-ions on the electrochemical processes is discussed     

n-Alkane isomerization on heteropolyacids

Acid-base properties of bulk 12-tungstophosphoric heteropolyacid (HPWA) and HPWA supported on alumina and fluorinated alumina were studied by DRIFT spectroscopy using adsorption of probe molecules. Catalytic properties of Pt-containing catalysts carried by these supports were studied inn-pentane isomerization. It was shown that the Pt/HPWA/Al₂O₃ system is almost inactive in isomerization as a result of the interaction of HPWA with basic sites of the alumina support. On the contrary, the presence of acidic sites in fluorinated alumina prevents HPWA destruction and favors the uniform distribution of HPWA on the support surface. As a result, enhancement of the activity and selectivity of the Pt/HPWA/Al₂O₃-F catalyst inn-pentane isomerization is observed. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1744–1750, October, 2000.     

Catalytic and physico-chemical properties of La1?xSrxCoO3 perovskites

Catalytic properties of strontium-substituted lanthanum cobaltites La_1–xSr_xCoO₃ in the reaction of CO oxidation were compared with the data about chemical composition of the surface and bulk defect structure. It was found that (1) the initial catalytic activity correlates with the cobalt concentration on the surface; (2) surface composition differs from the bulk one; (3) the steady-state activity is proportional to the density of bulk extended defects. Under our experimental conditions no role of point defects was noted.