Energetics of electron processes in semiconductor photocatalytic systems

The energetics of electron processes in photocatalytic systems based on dispersed semiconductors, their nanocomposites and heterostructures are examined. Methods for the approximate estimation and quantitative determination of their energetic characteristics are evaluated and energy diagrams of photocatalytic systems based on semiconductor nanocomposites and their heterostructures are plotted. Analysis of the diagrams permits the elucidation of the nature of their photocatalytic effects in redox reactions. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 03039, Ukraine. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 36, No. 2, pp. 69–89, March–April, 2000.     

Effect of Confinement on Structural and Spectral Characteristics of Composites of CsPbX3 Halide Perovskite Nanoparticles with Zeolites of Faujasite Structure

Theoretical and Experimental Chemistry - CsPbBr3–zIz/Y(X) nanocomposites based on FAU (Y and X) zeolites and halide perovskite nanoparticles (HP NP) with CsPbBr3–zIz composition (z = 0...     

Mono- and Few-Layer Nitrogen-Containing Graphenes as Sensitive Layers of Electrochemical Sensors for Selective Determination of Dopamine and Uric Acid in the Presence of Ascorbic Acid

Theoretical and Experimental Chemistry - A comparative study of electrochemical properties of mono- and few-layer samples of nitrogen-doped graphene as nanosized sensor materials for the...     

Molecular design in photocatalysis: Physicochemical principles for designing high-efficiency photocatalytic oxidation-reduction systems

We generalize the results of our research and develop the concept of molecular design as a strategy for controlling photocatalytic processes by designing organized systems in which all the conversions connected with electron transfer are coordinated.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 30, No. 4, pp. 175–191, July–August, 1994.We would like to express our deep appreciation to our colleagues A. V. Korzhak, N. F. Guba, and S. V. Kulik, the coauthors of our original papers which were the basis for this generalization.     

Investigations of polyfunctional oxides

The reaction of esters of 4,5-epoxy-2-hexenoic acid with ketones in the presence of acid catalysts gives 2,2,4-trialkyl-5-(2-carboalkoxyvinyl)-1,3-dioxolanes, the hydrogenation of which gives the corresponding saturated dioxolanes. The conformations and configurations of the dioxolanes obtained were studied by means of their PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 447–451, April, 1972See [1] for communication IV.     

The Effect of Heteropolyanion-Dopants on the Physicochemical and Electrochemical Characteristics of 3-Substituted Polythiophenes

It was shown that the physicochemical and electrochemical characteristics of 3-substituted polythiophenes, doped with Keggin-type heteropolyanions (PMo_12–n V _n O^(3+n)– ₄₀, n = 0-2), are determined both by the nature of the substituent at the position of the thiophene ring and by the redox characteristics of the dopants.     

Synergism in an organized photocatalytic system based on cadmium sulfide and titanium complexes

A nonadditive acceleration of oxidation-reduction processes has been observed in systems containing semiconductors and metal complex photocatalysts. The conditions necessary for synergism to occur have been analyzed for the example of the generation of H2 from aqueous alcoholic media with the participation of CdS and titanium(lV) complexes.Translated from Teoreticheskaya i Éksperimental'naya, Khimiya, Vol. 28, Nos. 5–6, pp. 407–410, September–December, 1992.The authors thank the Ukraine State Committee on Science and Technologyfor funding this study from the Fundamental Research Fund.     

The effect of the nature of the dopant on the sensor response of poly(3-methylthiophene) films

The effect of the nature of the dopant on the response of a sensor array based on films of poly(3-methylthiophene) under the influence of various organic solvents was studied. It was established that the electroconductivity of the polymer can both increase and decrease under the influence of the analytes. It was suggested that the main factors determining the magnitude of the response of poly(3-methylthiophene) are the ratio of the number of radical-cationic and dicationic states in the polymer, which depends on the nature of the dopant-anion, and also the polarity of the analyte. It was shown that the polymer has high sensitivity to chloroform vapor, which makes sensor arrays based on poly(3-methylthiophene) selective with respect to this analyte. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 331–338, November–December, 2006.     

Effects of a para-substituent in di-o-t-butylphenol on association with t-butanol

NMR studies reveal a linear correlation between the chemical shift for the OH proton in the phenol and the Hammett ^– for the substituent. The degree of association with t-butanol increases with the electron-acceptor affinity of the substituent. There is no fast exchange between the OH groups of the phenol and the alcohol; this is confirmed by SCF and Hückel calculations.We are indebted to A. I. Brodskii for valuable advice and to Yu. A. Kruglyak for assistance with the SCF calculations.     

Electrochemical functionalization of phenothiazine by nitrogen-containing heterocycles

We demonstrate the feasibility of electrochemically activated introduction of pyridine and nicotinarnide into the aromatic ring of phenothiazine with formation of N-(3-phenothiazinyl)-pyridinium perchlorate and N-(3-phenothiazinyl)-3-carbamide-pyridinium perchlorate. We have studied the physicochemical properties of the derivatives obtained.L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kiev 252039, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 2, pp. 83–87, March–April 1996. Original article submitted May 25, 1995.