Photochemistry andPhotobioiogv. 1967. Vol. 6, p. 601. Ptrgamon Press Ltd. Printed in Great Britain

BOOK REVIEW

Photochemistry. J. G. CALVERT and J. N. Pms, JR., John Wiley and Sons Inc., New York, 1966. pp. 899, $19.50. THERE HAS been a huge output in the literature of photochemistry since the second world war and the publica- tion of “Photochemistry” which has integrated all this work is therefore welcomed. The authors set out to write an extensive work which is attractive to a wide range of interests, from the advanced undergraduate level to that of the specialised research worker in the field. The general approach of the authors to the dficult problem of setting the balance between these interests has been to separate the formal course work from the results of research work in photochemistry.

The first chapter entitled light and the laws of photochemistry is very short and includes a description of the wave and particle nature of light, black body radiation and the laws of photochemistry. The next chapter on the interaction of light with atoms is essentially divided into two parts, the former dealing with the elements of atomic spectra and atomic structure and the latter, almost entirely with the photosensitised reactions and collision quenching of electronically excited mercury. The section on atomic structure is presented at a relatively elementary level with an emphasis on the language, selection rules and notation of atomic spectroscopy; the photochemistry of atomic mercury is dealt with in detail and constitutes a useful review for the research worker in the field. The spectroscopy and electronic structure of diatomic molecules is well presented at some length in the next chapter on the interaction of light with simple mole- cules, the remainder of the chapter dealing with the photochemistry of simple molecules, mainly small polyatomic molecules, from the viewpoint of the primary photolytic processes. The chapter on primary photophysical processes of polyatomic molecules is concerned mainly with the electronically excited states of organic molecules and here theory and experiment are well integrated. The discussion of the triplet state is particularly well presented in some detail and again the research worker will find the chapter a useful review of the field. This is followed by an extensive summary of the photochemistry of organic molecules, some 759 references being cited, and by the limitation of length is restricted to primary processes. The chapter which comprises a consideration of gas phase and solution kinetics and its application to photochemical systems is directed to the undergraduate audience who will find the problems at the end useful. The final chapter on experimental methods in photochemistry is detailed and experimental photo- chemists will find this to be of practical use.

Whilst sections of particular chapters which deal specifically with theory are usually directed at the advanced undergraduate audience, the inclusion of some discussion of Walsh correlation diagrams and the elements of some simple group theory would have been useful when describing the photochemistry of polyatomic molecules. The nature of the balance between formal theory and experiment for a book as extensive as this and aimed at a wide audience allows many alternatives. This book will clearly be useful to both the advanced undergraduate and the research worker in photochemistry. Some 1800 references are cited, many of them multiple references, and a number of them dated as recently as 1965, and whilst, as the authors point out, the appeal to the literature is occasionally not completely exhaustive, the work as a whole is extensive. The subject and author indices are full. The book is well printed and the figures and photographs are of a high standard, but it is, nevertheless, a little expensive. “Photochemistry” has answered the need for an extensive view of the subject appealing to a wide audience in a field in which there has been the absence of a major textbook for too long.

Department of Physical Chemistry University of Cambridge

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D. HUSAIN