# Book Review Unimolecular Reactions. Second edition. By K. A. Holbrook M. J. Pilling and S. H

код для вставкиСкачатьBOOKS stants, neither of which is discussed in the book, may often be possible in principle, but is usually not the most efficient approach. Also some important older and well-established techniques, such as spin decoupling, are not discussed. A more honest title for the book would be something like “Modern N M R Spectroscopic Techniques” . The inclusion of exercise problems with answers in each chapter is a welcome feature. Unfortunately, however, the questions posed are not always very useful from a learning standpoint (example: “The signal-to-noise ratio can be increased by [applying] proper apodization functions. What would happen without apodization?”), and occasionally they suggest a whimsical attitude on the part of the authors. For example, to the question of what type of probe-head is most suitable for a group of preparative chemists where the problem of insufficient sample does not arise. the answer given is “a probe-head for 10-15 mm sample tubes”. The book’s most serious shortcoming is that many of the figures are of very poor quality. This applies especially to the reproduction of spectra, a few of which have obviously been drawn by hand. Many of the 2D spectra are much too small. Occasionally the one-dimensional spectrum is missing from one of the axes, or is shown on such a small scale that only methyl group singlets are adequately reproduced (4 mm height!), with the result that no coupling multiplets can be recognized, since they would only be a fraction of a millimeter in height. This happens even on pages whose space is not fully used. The book would have been much improved by using a larger format and taking greater care with the layout. It needs to be thoroughly reworked. Ludger Ernst NMR-Laboratorium der Chemischen Institute der Technischen Universitat Braunschweig Braunschweig (Germany) Kerstin Ibrom Konigstein im Taunus (Germany) Angew Chem. Ii i l Ed Engl. 19%. 35, N o 19 Unimolecular Reactions. Second edition. By K. A . Holbrook, M . J. Pilling and S. H. Robertson. Wiley, ChiChester, 1996. 417 pp., hardcover .€ 90.00.-ISBN 0-471-92268-4 The subject of unimolecular reactions has undergone much development in the last few decades. Many new types of experiments have been carried out, affording insights that could scarcely have been imagined 30 years ago. It has become possible to make remarkably precise measurements on reactions of practical importance. Alongside these advances, theoretical methods now allow one to analyze the fundamental processes with improving quantitative reliability. Consequently, monographs and review articles dealing with this fast-moving field soon become outdated. It is therefore very pleasing that K. A. Holbrook, M.J. Pilling, and S. H. Robertson have now produced a thoroughly revised and significantly enlarged new edition of Unimolecular Reactions, first published in 1972 under the authorship of P. J. Robinson and K. A. Holbrook. In that first edition, “Robinson and Holbrook” contained an excellent introduction to the application of the H R R K M theory, the statistical theory of unimolecular reactions developed by Hinshelwood, Rice, Ramsperger, Kassel, and Marcus, together with a detailed compilation of experimental data on classical reactions. At that time this was the most detailed introduction to the practical application of the R R K M theory available in the literature. However, in recent years it had become seriously outdated because the many later developments were not covered. Thermal and nonthermal unimolecular reactions are often studied under conditions in which the reaction rate is determined solely o r partly by intermolecular energy exchange through collisions. In retrospect it seems surprising that for many years the details of this process received so little attention. The new edition of this book remedies that omission by including descriptions based on the fundamental equations. Nevertheless, perhaps an even more detailed treatment of the energy transfer process would have conveyed a better understanding of its characteristics. The new numerical algorithms for calculating densities of states and numbers of states are treated in detail in this book, so that the statistical analyses of the R R K M theory can be carried to completion. Thus, even a beginner should have no difficulty in learning how to treat reac- 0 VCH Verlugsgesellschuft mhH. 0.69451 Wemherm. 1996 tions involving rigid activated complexes, for which the classical R R K M theory was mainly developed. The new edition also includes a detailed treatment of reactions involving nonrigid activated complexes. The description and comparison of the different variants of theoretical treatments of the transition state is excellent and useful. In view of this it is even more surprising that the phase space theory, which represents the limiting case of completely flexible transition states, and makes it easy to correctly take into account the conservation of angular momentum in the reaction, is almost completely ignored. To have included a treatment of this limiting case would have helped the reader to understand the detailed description of the statistical adiabatic channel model. The book contains a wealth of information about current experimental and theoretical studies in this field. The descriptions of the kinds of investigations now possible are illustrated by informative examples, thus providing the beginner with an excellent introduction and the more advanced researcher with many stimulating ideas. It retains the spirit of the original “Robinson and Holbrook”, while also bringing the treatment up to date. If the book had been completely rewritten from the start, there would probably have been some changes of emphasis. It would then have been possible to devote more space to topics such as the breakdown of molecular ions, bimolecular complex-forming reactions of neutral or charged species, trajectory calculations, calculations of adiabatic channel potentials made possible by the latest methods, anharmonic densities of states, and (as already mentioned above) phase space theory. At the same time the treatment of the classical R R K M theory could be shortened. However, to do so would have resulted in a more bulky monograph than intended. Therefore the changes have been limited to a very successful updating of the original concept. The book is well suited as a text for further reading by advanced students, and will also serve the needs of reaction kineticists who intend to work on gas phase reactions. Jurgen Troe Institut fur Physikalische Chemie der Universitat Gottingen (Germany) 0570-0833196/35I9-2267 $15.00+ .25/0 2267

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