ELECTRONIC AND ELECTRICAL EFFECTS OF SOLVENTS

ELECTRONIC AND VIBRATIONAL SPECTRA OF COMPOUNDS IN CONDENSED MEDIA 

Department of Chemistry, University of Tartu, Tartu, Estonia 

The electronic-vibrational spectra of molecules can be substantially influenced by the surrounding condensed medium. The resultant effects arise from a variety of intermolecular interactions between the chromophoric solute and the solvent molecules in such media. Experimentally, these effects can be observed as 

Each of those, so-called solvent effects can be described theoretically using different model approaches. 

In each case, the direction and the size of the shift depends on the nature and electronic structure of the ground and excited state. For example, in the 

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Karelson, M. (2001) Electronic and electrical effects of solvents, in Handbook of Solvents (ed. G. Wypych), ChemTec Publishing, Toronto, Canada, pp. 639-682. 

Industrial scales, 26 243-245 Industrial, scientific, and medical (ISM) frequency allocations, 16 510-512 Industrial screens, types of, 16 616 Industrial separations, 16 633 Industrial sheeting, LLDPE, 20 207 Industrial solvents, 23 85-124 behavior of, 23 96-109 characteristics of, 23 89-96 classification of, 23 85-87 electronic and electrical effects of, 23 96-97... 

The electron spin resonance spectra were run in nitrogen-saturated solutions of aromatic compound ca. 10" m) and nucleophile (0-05-0-1 M) in the solvent(s) indicated. Irradiation in the cavity was effected with a high pressure mercury arc. Electrolysis was performed with the platinum cathode in the cavity, tetraethyl-ammonium perchlorate as electrolyte and electric currents of 10-250 /lA. 

In the previous section, it was pointed out that electrocatalysis is akin to heterogeneous catalysis. The essential differences are the effect of the electric field on the reaction rate and the presence of nonreacting species (ions of electrolyte, solvent), which may also affect the reaction rate. The following sections are concerned with (i) elucidation of the effect of the electric field on the reaction rate (n) role of adsorption which is somewhat more complicated in electrocatalysis by the fact that the adsorbed species are not only reactants, intermediates, or products, but also the solvent or ions of the solution (in) conditions under which a comparison of the electrocatalytic activity of various substrates for a particular reaction should be made (iv) the role of electronic and geometric factors of the electrocatalyst. 

Equation (15) takes into account the change of the reactant electronic state and of its intramolecular nuclear configuration, involving the transfer of the heavy particles, the change of the solvent polarization near the reactants and the effect of the reactants on the structure of the solvent contacting them, the approach of the reactants one to another and the separation of the products, the change of the ionic atmosphere around the reacting particles, and finally the effect of the electrode properties and the electric field on the probability of the elementary act and the rate of the electrochemical processes as a whole. 

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