As our knowledge of the mechanism of electrode processes increases, it becomes more and more apparent that the kinetic currents first observed by R. Brdicka and by K. Wiesner in the 1940's are very widely encountered. Very many electrode pro cesses contain a chemical stage. * This is true primarily of elec trode processes that involve organic compounds. Therefore, to understand the mechanism of electrode processes and, particular ly, to correctly interpret the results of polarographic investiga tions, it is important to know the characteristics and relationships controlling the chemical reactions taking place at the electrode surface. Generally, these reactions are substantially different from ordinary chemical reactions taking place in the bulk of the solution, since the reactions at the electrodes are often affected by the electric field of the electrode and the adsorption of the par ticipating compounds . The fact that hydrogen ions usuallY take part in the electro chemical reduction of organic compounds makes possible the use of electrochemical methods, particularly polarography, for the study of protolytic reactions. These reactions play an important role in organic chemistry: the majority of reactions of organic compounds in solutions go through a stage in which a hydrogen ion is removed or added (see, for example, [1, 2]). Therefore, the polarographic study of protolytic reactions can supply much important information to theoretical organic chemistry.

In the Soviet Union, investigations of electrochemical changes in organic substances are being conducted on a comparatively large scale and a large number of specialists are involved. This arises to a large extent from the necessity to solve problems in the applied fields, e.g. in the development of new improved methods for the analysis and synthesis of organic compounds or in the work on fuel cells. The attainment of substantial successes in this field has been linked inseparably with a deeper understanding of the mechanism and kinetics of electrolytic organic reactions and the utilization of modem research methods based on the latest achievements in instrumentation. The theory of organic electrode processes is therefore now developing rapidly. However, the propagation of information on this work has been relatively slow. The Series of reports on Progress in Electrochemistry of Organic Compounds should stimulate systematic treatment and propagation of information in this field of science. It is proposed that each volume of the series will be compiled on the same lines as the book Advances in Electrochemistry of Organic Compounds published by Nauka in 1966. They will form collections of original review articles on the most important aspects of the subject, prepared by competent authorities.

Despite reductions in the level of research activity in most fields which, for reasons of economic decline, have taken place in the U.S. during the last year or two, world progress in the fundamental aspects has continued actively. An important aspect of such recent work has been the use of nonaqueous solvents in studies on the constitution of the double-layer and electrochemical reactions. Interpretation of the behavior of electrode interfaces in such solvents demands more knowledge of the solvation properties of ions in nonaqueous media. Chapter 1 by Pad ova on "Ionic Solvation in Nonaqueous and Mixed Solvents" gives an up to date review of the present state of knowledge in this field, together with tabulations of data that are likely to be of quantitative value in further investigations of both homogeneous and heterogeneous electrochemistry in such media. Electrochemical studies of cathodic processes in nonaqueous solvents have, in recent years, revealed the role of solvated electrons. These are of interest in new approaches to reductive electro-organic synthesis. Similarly, the generation of hydrated electrons in photo cathodic processes is of great interest. In Chapter 2, by Conway, the conditions under which solvated electrons can arise in electrode processes are critically examined and the electro-organic reactions that hwe been investigated are reviewed. The supposed electro generation of hydrated electrons in the water solvent and as inter mediates in cathodic hydrogen evolution is shown to be unlikely.