Nuclear magnetic resonance

Chemistry, California Institute of Tech- ... is the best qualitative discussion of these topics which the reviewer has seen. ... pages of text and app...
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Nuclear Magnetic Resonance

John D. Robwk, Profemor of Organic Chemistry, California Institute of Technology. McGraw-Hill Book Co., Inc., 118 pp. New York, 1959. viii Figs. and tables. 16 X 23.5 cm. $6.

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Any effort to translate the principles of a field such as magnetic resonance, which properly belongs on the research frontiers of modern physics, into less mathematical language suitable to the average organic chemist deserves our attention and support. Professor Roberts has on the whole been successful in presenting such a translation with little loss in rigor, and he has made clear the wide range of interesting organic chemical problems to whioh the techniques of nuclear magnetic resonance (NMR) can be usefully applied. (No doubt most of the future development and use of NMR will be carried out by chemists, simply 'because they are more aware of the problems susceptible to attack by the method.) Roberts' Preface states that the "coverage is illustrative rather than comprehensive," and this statement characterizes the book. I t will not make the reader a capable operator of NMR equipment, nor will it make him an expert on the interprotation of the data. The first two chapters discuss the phenomenon of NMR and the nature and determination of the chemical shift parameter, which is the measurable quantity of greatest interest to the chemist. Tho treatment of nuclear relaxation and the characteristic relaxation times in chapter one is the best

qualitative discussion of these topics which the reviewer has seen. Appendix A contains a treatment of the Bloch equations for NMR line shapes, given in sufficient detail to avoid the usual gaps which are supposed to be "obvious" to the reader of such derivations. A series of plots of the phase relatiofis of the radio frequency signal and the induced field a t the receiver coil under various conditions of R F signal leakage is used to demonstrate with admirable clarity how the equipment must be operated to detect a pure absorption signal. Chapters three and four describe the use of spin-spin splitting8 in the determination of structure and the applicstion of NMR to studies of reaction kinetics. They successfully indicate the scope of these applications to organic chemistry (but not its other branches), and suggest Borne of the pitfalls in the interpretation of NMR spectra. Chapter 5 is a brief discussion of nuclear electric quadruple effects and the highly specialized double resonance teehnique. Appendix C contains twenty problems on the determination of structure from the molecular formula and NMR spectrum of an unknown compound. Same of these depend upon rather specialized points mentioned briefly in the teut, and the calculation of chemical shifts is handicapped by an error in the units used in the fourth column of Tahle 1-1, which lists the proportiondity constants relating magnetio field strength and frequencies which inducc resonance. The column is headed "megacycles per kilogauss," but

the correct unit is megacycles per ten kilogauss, as stated on page 18. Roberts' book is the best available brief introduction to tho princ~plesand particularly to the organic chemical applications of NMR. His treatment of these topics is adequate for the requirements of the workmg organic chemist or for the studcnt who wants to know what NMR is and what i t can do. More rigorous and detailed discussions are available, and would be necessary for snyone planning active work in the field; references to these are collected in .ippendix B. ROBERTI. WALTER Haverford College Hauerfod, Pansyluania Phosphorus and Its Volume 1: Chemistry

Compounds.

John R. Van Waxer, Assistant Resesrch Director, Inorganic Chemicals Division, Monssnto Chemical Ca., St. Louis, Missouri. Interscience Publishers, Inc., Xew York, 1958. xii S- 954 pp. Many figs. and tablea. 16 X 23.5 cm. $27.50. The author's stated purpose in this book is "to lay a foundation for a new separate discipline-phosphorua chemistry." Some unifying principles are stated, such as the stability of quadruply connected phosphorus as compared t o triply, and quintuply connected phosphorus. Some compsrisons are made for carbon, silicon, and phosphorus, with respect t o bonding, catenation, and rates of reaction. However, after the book is digested, it seems questionable to the revienw a.hether phosphorus chemistry uill prove to be sufficiently unique to permit the establishment of a. separate discipline. The author has made no attempt t o "review exhaustively the literature of phosphorus and its compounds," but the 889 pages of text and appendixes, and more t h m 3000 literature citations (some duplication from chapter to chapter), atests to the fact that a tremendous volume of litemture has been covered, (through part of 1957). Certamly this volume is a. very important contribution to the study of phosphorus chemistry. The author is t o be complimented for taking on and sticking to such a herculean task. A second volumeon the technology, functions, and applications will follow. I n the first three chapters the ground work is laid for the discussion of the detailed chemistry of tho following chapters. These chapters contain some of the simplest concepts of chemistry presented in unusual detail for this type of book. For instance, "electrons are diffuse negative charges with essentially no mass," ''these superscripts add up to 15'' (in the electronic configuration of the neutral phosphorus atom), and the discussion of ionic and covalent bond on page 10. On the other hand, some of the more advanced physical chemical principles are presented in a brief and approrimate fashion. In C h a p ter 2 the relationship between rr-bond character and bond distances is developed, and although the author comments that "this does not, however, show that r-bonding is the common cause far ob-

Volume 36, Number 10, October 1959

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