Polarographic properties of ubiquinones with isoprenoid chains of different lengths

It has been shown that in aqueous ethanolic solutions the polarographic potentials E₁/₂ for ubiquinones with isoprenoid chains with different lengths are the same, –0.235 V (relative to a normal calomel electrode) at pH 7.9, and correspond to quasi-irreversible reduction with the addition of 2e^–/2H⁺. It has been found that the potential E₁/₂ for the ubiquinone UQ-O having no isoprenoid chain is more positive by 57 mV relative to the potentials of the other ubiquinones.Institute of Soil Science and Photosynthesis, USSR Academy of Sciences, Pushchino. Moscow Oblast. Translated from Khimiya Prirodnykh Soedinemii, No. 5, pp. 703–707, September–October, 1988.     

Ferric chloride catalyzed photooxidation of alkanes by air in organic solvents

In the presence of catalytic amounts of FeCl₃, alkanes (cyclohexane, n-hexane), toluene and ethylbenzene are oxidized by air oxygen to CH₃CN, (CH₃)₂CO or CH₂Cl₂ under visible light irradiation to yield ketones and alcohols.

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FeCl₃ (, -), CH₃CN, (CH₃)₂CO CH₂Cl₂ .

     

Synthesis of colloidal silica dumbbells

We describe the synthesis and characterization of stable suspensions of monodisperse fluorescently labeled silica dumbbell particles. Pure dispersions of silica dumbbells with center-to-center lengths from 174 nm to 2.3 microm were produced with a variety of aspect ratios. Individual particles in concentrated dispersions of these particles could be imaged with confocal microscopy. These particles can be used as a colloidal model system for addressing fundamental questions about crystal and glass formation of low-aspect-ratio anisotropic particles. They also have potential in photonic applications and electro-optical devices.     

New method for the prediction of antibacterial properties of semisynthetic penicillins. 2. Evaluation of activity levels

In the case of various types of semisynthetic penicillins it is demonstrated that it is possible to use statistical indexes that characterize the probability of the development of structural elements in fixed positions of the side chain to predict the antibacterial properties of semisynthetic penicillins.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 683–687, May, 1989.     

Effect of hydroxyl and oxygen ions on optical stability of F-centers in KBr crystals

The effect of the anionic impurities OH^–, O ₂ ^§- , and O^2– on the optical stability of F-centers in KBr crystals was investigated. It is shown that the stability of F-centers is independent of the presence of hydroxyl ions (OH^–) and molecular oxygen ions (O ₂ ^– ) in the crystal lattice. It is suggested that the low stability of F-centers in KBr-KOH crystals is due to doubly charged oxygen ions.Translated from Izvestiya Vysshikh Uchebnykh Zavendenii, Fizika, No. 10, pp. 107–112, October, 1972.     

Calculation of the Stokes-component amplification with bias illumination in the anti-Stokes region

The effect of Raman absorption in the anti-Stokes region on Stakes-component Raman scattering is discussed for the case of stimulated Raman scattering. It is shown that the Raman interaction leads to a significant amplification of the Stokes-component radiation and that the anti-Stokes radiation converts into Stokes radiation in proportion to the ratio _s/ _as.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 12, No. 7, pp. 112–115, July, 1969.     

Coherent Transport of Electron Excitations in Organic Solar Cells

Journal of Experimental and Theoretical Physics - The mechanisms of formation and coherent transport of free and bound electron excited states in organic solar cells are considered. In the model of...     

Excited Electron–Hole States in Molecular Chains

The eigenvalues and the eigenfunctions of molecular excitons, charge-transfer excitons, and electron–hole pairs have been found in the approximation of electron and hole transfer between the lowest unoccupied and highest occupied orbitals in a rigid molecular chain of identical photosensitive molecules, the recognized model of organic solar cells. It has been shown that as the Coulomb binding energy decreases, the wave functions become superposition of functions of the increasing number of sites and the decay time, determined by electron or hole transitions, is shorter that the transfer time of the exciton as a whole, so that energy transfer and charge transfer become interrelated processes.