Photochemistry historical aspects

The two parts of the present volume consist of 17 chapters written by experts from 10 countries. They start with historical background, followed by chapters on the theory, structure, thermochemistry, photophysics and photochemistry and electrochemistry of anilines, on their mass spectrometry, NMR spectra and analysis and on their modern syntheses by transition metal catalysed processes. Other chapters deal with their rearrangements, their reactivity as nucleophiles, their use as solvatochromic probes, their hydrogen bonded complexes, and their versatile uses in the chemical industry, and the relevant topic of toxicity and environmental aspects. A chapter on a special group of anilines—the proton sponges—ends the book. 

As mentioned, the observation of chemical effects of light is as old as mankind itself. Accounts of the earlier history of photochemistry have been presented by several authors. Long erudite lists of reference are of little usefulness, however. Here, it has been chosen to present a brief historic profile based on a document itself of historic value, the introduction written by a great authority, professor Ivan Plotnikov. This well-known Russian-bom scientist published in 1910 a book on photochemistry which was followed in 1936 by a second, much extended, edition of over 900 pages. The view he had on this science, or at least on some aspects of it, in particular the unconditioned refusal of the Stark-Einstein equivalence law, appeared obsolete at the time of the second edition, as it is discussed in Sect. 2.3. However, Plotnikov can certainly not be accused of insufficient knowledge of the matter or of insufficient exploration of the literature and his book is a rich mine of data and thoughts [7]. 

Photochemical reactions of compounds containing a P,y-enone chromophore have generated intense interest for more than two decades " and even more so in recent years.Several excellent reviews dealing with various aspects of P,y-enone photochemistry have appeared. " A good historical background on the photoreactions of P,y-enones is described by Schuster. In principle, P,y-enones can undergo photoreactions that are characteristic of carbonyl and olefinic chromophores, such as photoreduction, epimer-ization and cis,trans-isomerization, [2-F2]-cycloaddition, etc. They also undergo two unique reactions as... 

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