Kinetic models for the chemisorption of organic compounds on oxide surfaces

A kinetic equation for chemisorption on amorphous oxide surfaces is proposed, and activation energies, pre-exponential factors for reactions of various organosilicon compounds with Si, Ti and Al oxide active sites are calculated. Relationships between the kinetic parameters and reagent structure were established.     

Influence of the nature of the central atom of onium cations on the rate and selectivity of processes of their one-electron reduction

It was shown that the rate and selectivity of irreversible processes of electrochemical and chemical reduction of onium cations of elements of groups V-VII, containing alkyl and aryl substituents, increase with increasing principal quantum number of the central atom of the cation. This pattern is explained on the basis of the Marcus theory by a decrease in the energy of heterolytic dissociation of the bonds of the substituent to the central atom of the cation, leading to a decrease in the free energy and energy of reorganization of the reaction, as well as to an increase in their rate and selectivity.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 4, pp. 468–470, July–August 1987.     

Quantum-chemical study on electrode field effects in elementary stages in electrochemical methyl chloride reduction

MINDO/3 has been applied to the effects of field strength and direction on elementary stages in electroorganic reaction, the electrochemical reduction of methyl chloride: molecule and anion-radical orientation, electron transfer from electrode to molecule, anion radical dissociation, and methyl radical and anion inversion. The molecular electronic and stearic structures are affected by the field, as are those for the anion radical, the molecular and radical reorientation barriers, the direction and height in the radical dissociation barrier, and the radical and anion configuration stabilities. An explanation is given for the electrolysis data for alkyl halides and for the properties of chemically modified electrodes.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, No. 4, pp. 412–420, July–August, 1989.     

Evaluation of Desorption Energy Distributions from TPD Spectra on a Heterogeneous Solid Surface

The condensation approximation (CA) and numerical regularization procedure (RP) methods used to solve a Fredholm integral equation of the first kind describing the adsorption equilibria on a heterogeneous solid surface under isothermal conditions have been adopted in the present study to evaluate desorption energy distributions from temperature-programmed desorption (TPD) spectra. From comparisons of the computational results obtained by means of these methods on the basis of simulated TPD spectra, it follows that the CA gives stable solutions for wide desorption energy distributions and it can be used successfully for calculations from wide and clear resolved peaks in the TPD spectra. The use of the RP is more advantageous for acquisition of the distributions from closely related narrow peaks in the TPD spectra. This revised version was published online in July 2006 with corrections to the Cover Date.