Effects of mixed conductivity of nanocomposite membranes MF-4SC/PANI

Changes in the conducting and hydrophilic properties of composites MF-4SC/polyaniline (PAni) under conditions of prolonged synthesis have been studied. A maximum of PAni content of about 0.20 by weight, which can be incorporated into the matrix of MF-4SC under these conditions of synthesis, is determined. Percolation behavior of electrical conductivity of the composites after drying was observed. The conductivity of PAni salt inside MF-4SC was estimated within the frames of the percolation model. Using the fibrous cluster model of the membrane and the conductivity data on individual PAni, theoretical assessment of the electrical conductivity of nanocomposite MF-4SC/PAni has been performed. Reasons for a significant reduction in the conductivity of PAni during its integration into the structure of the initial matrix were discussed. A scale of membrane conductivity, reflecting changes in the electrical conductivity of composites at various stages of synthesis, was drawn.     

Colloidal catalysts based on iron(III) oxides. 1. Decomposition of hydrogen peroxide

The catalytic activity of a colloidal catalyst based on iron(III) oxides in decomposition of H₂O₂ is studied. The catalyst is obtained by hydrolysis followed by peptization of FeCl₃ · 6H₂O salt in water in the presence of 1% ethanol. The structure, composition, and size of colloidal particles of the catalyst are studied by the methods of Mössbauer spectroscopy, X-ray fluorescence, X-ray diffraction, and transmission electron microscopy. The obtained catalyst is based on α-Fe₂O₃ crystals with an admixture of other crystalline structures of iron oxides and carbon-containing compounds. The activity of the catalyst with respect to H₂O₂ decomposition undergoes nonlinear and nonmonotonic variations and its particle size enlarges beginning from 1 to 3 nm with increasing initial concentration of FeCl₃ · 6H₂O. The catalyst obtained under optimal conditions exhibits high activity corresponding to the most efficient agents of H₂O₂ decomposition.     

4,7-Diphenyl-2-(p-dimethylaminophenyl)-1,3-indanedione and its dehydrodimer

Conclusions 4,7-Diphenyl-2-(p-dimethylaminophenyl)-1,3-indanedione is obtained by the Perkin-Gabriel reaction, with subsequent oxidation to the dehydrodimer.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 637–640, March, 1986.     

Effect of cationic surfactants on limonene oxidation

Kinetic regularities of free radical formation during limonene oxidation with molecular oxygen in a chlorobenzene solution at 60 °C were studied by the inhibitor method under autooxidation conditions and with additives of surfactants (cetyltrimethylammonium chloride and bromide) using dimer 2,2′-bis[2-(p-dimethylaminophenyl)indane-1,3-dione] and α-tocopherol as acceptors of radicals. In the presence of the surfactants, the rates of radical generation and oxidation increase sharply. The catalytic activity of cetyltrimethylammonium chloride is much higher than that of the corresponding bromide.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2110–2113, October, 2004.     

Crystal and molecular structure of 2,2′-bis[2-(p-dimethylaminophenyl)indane-1,3-dione] displaying mechanochromic properties

Institute of Chemical Physics, Academy of Sciences of the SSSR. Institute of Physiologically Active Compounds, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 5, pp. 103–107, September–October, 1990.     

Influence of onium substituent in phthaloyl ring on thermodynamic parameters of equilibrium between dimer and free radicals of 2-(4-dimethylaminophenyl)-1,3-indandiones

2,2-Bis[2-(4-dimethylaminophenyl)-5-trimethylammonio-1,3-indandione] diperchlorate and 2,2-bis[2-(4-dimethylaminophenyl)-5-(2,4,6-triphenylpyridinio)-1,3-indandione] diperchlorate have very definite thermochromic and mechanochromic properties, owing to reversible dissociation into free radicals. The rupture energy of the central bond C²-C² in 5-substituted 2,2'-bis[2-(4-dimethylaminophenyl)-1,3-indandiones] in acetonitrile is 63–75 kJ/mole; in the dimer with the bulky 5-(2,4,6-triphenylpyridinium) substituent, the rupture energy is 51 kJ/mole. The equilibrium constants follow the Hammett equation (p=1.53, acetonitrile, 293 K). Radicals with onium substituents are thermodynamically the most stable of the arylindandionyl radicals that are thus far known, owing to the significant contribution of electrostatic interactions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1525–1531, July, 1990.     

Dipole moments of the carbonyl groups in cyclic β-diketones from IR spectroscopy data

The _CO angles between the carbonyl groups and the dipole moments of a number of 2-arylindan-1,3-diones were determined from the data of IR spectroscopy. The effects of substituents on _CO depending on their positions and inductive factors were found. It was established that the interaction between the vibrations of the carbonyl groups depends on both the _CO angle or the _CO dipole moment and the coplanar arrangement of these groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 692–698, April, 1995.     

Free radical formation during ethylbenzene oxidation catalyzed by cetyltrimethylammonium bromide

The dimer of 2,2"-bis[2-(p-dimethylaminophenyl)indane-1,3-dione] and -tocopherol were used as free radical acceptors in a study of the kinetic regularities of free radical formation during ethylbenzene oxidation by molecular oxygen at 60 °C. The reaction initiated by the -phenylethyl hydroperoxide—cetyltrimethylammonium bromide (CTAB) catalytic system, which generates free radicals. The oxidation kinetics was analyzed using computer simulation.