Chemical Education Today
Spin Choreography: Basic Steps in High Resolution NMR Ray Freeman. University Sciences Books: Sausalito, CA, 1997. ISBN: 0 935702 95 4. Hardcover, $65.
There are three orientations that NMR courses may take. The traditional molecular structure course focuses on the interpretation of spectra and the use of chemical shifts, coupling constants, and nuclear Overhauser effects (NOE) to sort out subtle details of structure and stereochemistry. Courses can also focus on the fundamental quantum mechanics of observable NMR parameters and processes such a spin– spin splitting and relaxation. More recently there are courses devoted to the manipulation of nuclear spins and the basic steps of one- and two-dimensional NMR experiments. Freeman’s book is directed towards the latter audience. Modern NMR methods offer a myriad ways to extract information about molecular structure and motion by observing the behavior of nuclear spins under a variety of conditions. In Freeman’s words: “We can lead the spins through an intricate dance, carefully programmed in advance, to enhance, simplify, correlate, decouple, edit or assign NMR spectra.” This is a carefully written, well-illustrated account of how this dance is choreographed by pulse programming, double resonance, and gradient effects. Although well written, this book is not an easy read; every word counts. It is recommended for graduate courses that emphasize the fundamentals of magnetic resonance. It is not a text on interpretation of spectra. Ray Freeman is one of the principle impresarios of this ballet. In a recently published anthology of “classical” NMR papers taken from the Journal of Magnetic Resonance over the last quarter century, Freeman was the most frequently selected
author. The unusually creative insight he has brought to the development of novel NMR experiments comes through in his choice of analogies and how he integrates written descriptions with carefully chosen diagrams. The heavy use of drawings is an important virtue of this book. The famous Freeman sense of humor is still present, but toned down from his earlier book (Handbook of Nuclear Magnetic Resonance). There are no cartoons here, only serious diagrams. Also important are the mental pictures he creates to visualize nuclear spins from various points of view and his integration of these approaches. Each of the first three chapters introduces one of these viewpoints. Chapter 1 introduces energy level populations and the use of population level diagrams. The idea of coherence is also introduced. Chapter 2 is an excellent treatment of the traditional vector model with a clear discussion of its limitation in describing multiple-quantum coherence. The description of COSY experiments in terms of a vector model of polarization transfer is especially well done. Chapter 3 is an introduction to the product operator formalism. This begins easily enough but soon becomes tough sledding through topics like three-spin coherence. The remaining nine chapters are self-contained units covering specialized topics such as spin echoes, decoupling, NOE, and spectral editing. Unfortunately, except for a few suggestions in Chapter 3, there are no worked problems and students are left to apply the general principles given in this book to new situations on their own. Michael J. Minch Department of Chemistry University of the Pacific Stockton, CA 95211
