EXAMPLES OF INDUCED REACTIONS

Although in the fifties of the last century it had already been recognized that in several oxidation-reduction reactions the co-existence principle i.e. the assumption that the individual processes take place independently of each other) was not valid and to date many examples of chemical induction have been found, there are only a few cases known where the mechanism of the induced reaction has been satisfactorily elucidated. There are several reasons for this. Some of the induced reactions take place too rapidly to be investigated by conventional kinetical methods in other cases a thorough investigation was frustrated by the lack of appropriate analytical methods. 

Chemical analysis of composite systems is often severely restricted by the invalidity of the co-existence principle (although there are a few cases known in which estimations are made possible just because of the occurrence of chemical induction). Therefore, many efforts have been directed at exploring at least qualitatively the source of errors caused by induced reactions. That is why our present knowledge about such reactions is rather qualitative in nature. 

Because of the foregoing we will not attempt in this article to compile every observation recorded so far in the field of induced reactions only the results where the mechanism is sufficiently clear will be referred to. Also, the wide and technically important field of autoxidation processes will be omitted, because they can be considered more properly later in the series. 

Systems selected for discussion will be presented below according to the reactive species involved in the induced reactions. 

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