Quantum Size Effects in Semiconductor Photocatalysis

The characteristics of photocatalytic systems based on nanostructural semiconductors, characterized by quantum size effects, are discussed. An analysis is made of the consequences of exciton quantum confinement in the volume that are significant for photocatalysis and, in particular, the increase in the energy of photogenerated charges with decrease in the particle size, the photoinduced polarization processes, and also the simultaneous display of these effects. Possible ways of further increasing the effectiveness of systems based on nanostructural semiconductors are examined. __________ Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 41, No. 4, pp. 199–218, July–August, 2005.     

Aromatic amines — Electron transfer agents which increase the effectiveness of photocatalytic redox reactions

The characteristics are examined of redox photocatalytic systems based on semiconductors containing both electron accepting and electron donating additives which are able to separate the photogenerated charges. The use of aromatic amines as electron transfer agents has been demonstrated experimentally.Translated from Teoreticheskaya Éksperimental'naya Khimiya, Vol. 28, Nos. 5–6, pp. 411–415, September–December, 1992.The authors thank the Ukrainian State Committee on Science and Technology for financial help from the Fund for Fundamental Research.     

Effect of the nature of the organic aprotic electrolyte on processes of electrochemicalp-doping/de-doping of soluble polyaniline

We have investigated the effect of the nature of the aprotic organic solvent and the supporting electrolyte on the electrochemical and spectrophotometric characteristics of soluble polyaniline perchlorate and tetrafluoroborate. We have established the presence of solvation and donor-acceptor interactions in the solublep-doped polyaniline-organic aprotic electrolyte system.L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Nauki Prosp., Kiev 252039, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 4, pp. 224–228, July–August, 1996. Original article submitted October 27, 1995.     

Life and work of academician L. V. Pisarzhevskii (on the 120th anniversary of his birth)

The life and work of the founder of the L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Academician Lev Vladimirovich Pisarzhevskii, are examined.Report to the Jubilee Session dedicated to the 120th anniversary of the birth of Academician L. V. Pisarzhevskii (General Meeting of the Chemistry Section of the National Academy of Sciences of Ukraine, March 22, 1994).Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 6, pp. 471–481, November–December, 1993.     

Spectral Characteristics and Surface Morphology of Organic Polymer Films Containing Vanadium Pentoxide Nanoparticles

Films of nanosized composites of poly(N-epoxypropylcarbazole) (pEPC) and poly(3,6-di-Br-N-epoxypropylcarbazole) (pdBEPC) with vanadium pentoxide (V₂O₅) are produced for the first time ever. The electroconduction in dark and when illuminated, absorption spectra, steady-state photoluminescence spectra, and time-resolved photoluminescence spectra for the composite films are studied. The results are compared with relevant data for the pEPC, pdBEPC, and V₂O₅films. A conclusion about the formation of donor–acceptor complexes with incomplete charge transfer [pEPC⁺···V₂O ₅ ^- ] and [pdBEPC⁺···V₂O₅ ^-] is made. The surface morphology of the composites differs in the size of V₂O₅ fibers and polymer grains; the polymer inclusions in the composites are of different character. A surface morphology study reveals that the composite constituents—polymer base and V₂O₅ fibers—are nanosized.     

Electrochemical activation and carboxylation of fluorine-containing aromatic imines

On the basis of a study of the processes involved in the electrochemical activation of a series of fluorine-containing aromatic imines with and without the presence of carbon dioxide it was shown that the initial stage of such processes is the formation of imine radical-anions, which can both undergo spontaneous transformations and react with CO₂ with the formation of fluorine-containing amino acids. A correlation was established between the effects of the electronic structure of the imines on the electrochemical characteristics of their reduction and on the stability of the radical-anions. A relationship was established between the parameters of electrochemical activation of the imines in the presence of CO₂ and the yields of the amino acids. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 44, No. 5, pp. 265–271, September–October, 2008.