- Email: [email protected]
Fundamentals of Molecular Spectroscopy
BOOK
REVIEWS
On the whole, the book is well balanced and comprehensive (perhaps Surface Enhanced Raman Spectroscopy (SERS) is the only exciting technique that has been left out) of the more recent techniques on vibrational spectroscopy. It provides an excellent way to realize the large variety of problems that are faced today in the area, and it also proves the healthy vitality of this field. R. Escribano Institute de Estructura de la Materia Madrid, Spain Walter S. Struve, Fundamentals of Molecular Spectroscopy, Wiley, New York, Chichester, 1989 (ISBN O-471-85424-7). xii + 379 pp. Price E 39.50. This is a substantial textbook; it is almost a research monograph rather than a textbook, and the readership will be mainly research workers in gas phase high-resolution molecular spectroscopy. It is written with authority, and it is a valuable book in a field of growing importance. It is described in the preface as having grown out of a graduate level molecular spectroscopy course at Iowa, and the author states that most of the book can be comfortably accomodated within a one-semester course. The material covered concerns rotation, vibration and electronic spectroscopy of diatomic and polyatomic molecules, lasers, Raman spectroscopy, and non-linear effects. However the book makes no apology for the fact that the subject calls for theoretical treatment at a sophisticated level. It is assumed that the reader is already familiar with electromagnetic theory, quantum mechanics, and group theory, and the book is concerned with the application of these techniques to spectroscopy, and to some extent to valency theory and quantum chemistry. For an advanced text I believe this is the correct approach, but I think that it would be a first class graduate student that could absorb this material in a one semester course. A major criticism concerns symbols, units and dimensions. The author does not follow the rules of quantity calculus; thus he writes equations like X = 3645.6m2/(m2 - 22), on p. 35, which clearly should involve a unit. He follows the prevailing
sloppy habit of using the word frequency to mean wavenumber (e.g. p. 75), and at other times he uses the words “units of cm-i ” to mean “dimensions of waverrbmber” (e.g. p. 168). Although he states on p. 11 that the book uses SI, in fact this is a fib: non-S1 units abound. Indeed, on p. 10 we are given a table of molecular polarizabilities, a, in units A3. The definition of (Y on the preceding page correctly suggests that the SI unit should be .I m2 V2, but no help is provided to relate this to A3 (the answer, of course, involves introducing the esu system). I have no objection to the use of some non-S1 units, provided they are properly related to the SI; the angstrom, debye and electronvolt, for example, all have their place in quantum chemistry. But I believe they should be accompanied by the strict use of quantity calculus (quantity = number X unit), with a careful distinction between quantities and units, and the use of SI equations (rather than esu, emu, or Gaussian equations) in electromagnetic theory. These are not trivial difficulties to the student; they deserve care and attention from the authors of textbooks. Finally the fundamental constants in Appendix A are 15 years out of date: they are the 1973 rather than the 1986 recommended values. I also have some criticism of the choice and arrangement of material. Like many before him, this author persists in using wavelength A to label spectral lines and the regions of the spectrum, when wavenumber F = l/A shows up the relation to energy formulae so much more vividly. Modem instruments produce beautiful spectra, on a linear wavenumber scale, yet some of those reproduced in this book are antiquated (e.g. p. 75 and p. 76); the author could so easily have included many beautiful spectra to illustrate his points. The treatment of rotation and vibration-rotation spectra is weak compared to the rest of the book (one suspects that this is not the author’s field); the chapter on lasers contains no mention of CO,, CO, colour centre, diode, or difference frequency lasers in the infrared, nor of excimer lasers, frequency doubling, and Raman shifting, to access the UV; the Nd-Yag laser just barely gets mentioned. On the theoretical treatments, which one senses to, be the author’s strength, the book invites comparison with Herzberg’s famous volumes, in which much of the
VIBRATIONAL
104
same material is covered -with greater clarity in my view. Having made my criticisms, I want to welcome this book. There are few enough authoritative treatments of this subject in any form, and this book gives a correct feeling for the theoretical base of the subject and its importance in quantum chemistry. I hope that it runs to a second edition, which -with revisionsmight become a first class textbook. I. Mills University of Reading Reading, Great Britain D.J. Gardiner and P.R. Graves (Eds.), Practical Raman Spectroscopy, Springer Verlag, Berlin, 1989 (ISBN 3-540-50254-8). viii + 157 pp. Price DM 78.00. Although this is a slim volume, only 157 pages, it is an excellent book and a very welcome addition to the relatively scarce Raman literature. It is useful to both the beginner with elementary, but well written material and to the practicing spectroscopist as a quick reference book. The hope of the editors was to “provide a source of on-hand technical support and data for the practicising Raman spectroscopist in the laboratory.” This they have done. One hopes the the next edition will be expanded and more comprehensive. The introduction is very elementary, but a nice discussion of classical theory and quantum theory of Raman scattering. It would have been a good idea to include some elementary theory of SERS enhancement in this chapter. George Turrell’s chapter on Raman sampling is exceptionally well written. Although the author appologizes for not being able to include everything within the scope of a small book, we find many useful things which are not readily found elsewhere. He presents a selection of the most important developments in sampling different types and morphologies of samples; and he provides good basic physics and mathematical treatment behind different methods. It is this aspect we find very useful and refreshing. Instrumentation for Raman Spectroscopy is a
SPECTROSCOPY
good review chapter on instrument design. This chapter could be improved by adding more rigorous physical optics/mathematical treatment of the issues involved. The section on detectors and gratings is particularly well written with a wealth of information in it. We disagree with the statement of p. 71 that “it is not normally possible to use them (intensified detector arrays) for studying bands close to the exciting line.” With well designed spectrometers, stray light is not a problem and even with solids one can approach quite close to the excitation line. Pierre Graves’ chapter on calibration and data handling is a good review, and we are particularly glad to see the introduction of the maximum entropy method of image reconstruction. The chapter on non-standard physical and chemical environments is very well organized into convenient sections on high temperature, low temperature, high pressure and special chemical environments. It is a very good, quick reference and starting point when looking into particular experiments. The chapter on Raman microscopy by J.D. Louden is especially welcome. This area has emerged as a major development in Raman spectrocopy in the last several years. In addition to covering the historical background and basic principles of micro-Raman, there is considerable information of a very specific and practical nature. The examples are quite good and include temperature and pressure techniques, illumination techniques, polarization ratios, spatial resolution and spatial filtering and Raman imaging and mapping. Recent promising developments in Hadamard transform Raman imaging by P. Tread0 and M. Morris at the University of Michigan could have been included in the section discribing Raman imaging and mapping. Actually, the major criticism of this book is the quality of the binding (paperback). After only a few times going through it, the book literally fell apart. That is a shame, because anyone in Raman spectroscopy will want to use it frequently. M.A. Hazle M. Mehicic B. P. Research International Cleveland, OH, U.S.A.
REVIEWS
On the whole, the book is well balanced and comprehensive (perhaps Surface Enhanced Raman Spectroscopy (SERS) is the only exciting technique that has been left out) of the more recent techniques on vibrational spectroscopy. It provides an excellent way to realize the large variety of problems that are faced today in the area, and it also proves the healthy vitality of this field. R. Escribano Institute de Estructura de la Materia Madrid, Spain Walter S. Struve, Fundamentals of Molecular Spectroscopy, Wiley, New York, Chichester, 1989 (ISBN O-471-85424-7). xii + 379 pp. Price E 39.50. This is a substantial textbook; it is almost a research monograph rather than a textbook, and the readership will be mainly research workers in gas phase high-resolution molecular spectroscopy. It is written with authority, and it is a valuable book in a field of growing importance. It is described in the preface as having grown out of a graduate level molecular spectroscopy course at Iowa, and the author states that most of the book can be comfortably accomodated within a one-semester course. The material covered concerns rotation, vibration and electronic spectroscopy of diatomic and polyatomic molecules, lasers, Raman spectroscopy, and non-linear effects. However the book makes no apology for the fact that the subject calls for theoretical treatment at a sophisticated level. It is assumed that the reader is already familiar with electromagnetic theory, quantum mechanics, and group theory, and the book is concerned with the application of these techniques to spectroscopy, and to some extent to valency theory and quantum chemistry. For an advanced text I believe this is the correct approach, but I think that it would be a first class graduate student that could absorb this material in a one semester course. A major criticism concerns symbols, units and dimensions. The author does not follow the rules of quantity calculus; thus he writes equations like X = 3645.6m2/(m2 - 22), on p. 35, which clearly should involve a unit. He follows the prevailing
sloppy habit of using the word frequency to mean wavenumber (e.g. p. 75), and at other times he uses the words “units of cm-i ” to mean “dimensions of waverrbmber” (e.g. p. 168). Although he states on p. 11 that the book uses SI, in fact this is a fib: non-S1 units abound. Indeed, on p. 10 we are given a table of molecular polarizabilities, a, in units A3. The definition of (Y on the preceding page correctly suggests that the SI unit should be .I m2 V2, but no help is provided to relate this to A3 (the answer, of course, involves introducing the esu system). I have no objection to the use of some non-S1 units, provided they are properly related to the SI; the angstrom, debye and electronvolt, for example, all have their place in quantum chemistry. But I believe they should be accompanied by the strict use of quantity calculus (quantity = number X unit), with a careful distinction between quantities and units, and the use of SI equations (rather than esu, emu, or Gaussian equations) in electromagnetic theory. These are not trivial difficulties to the student; they deserve care and attention from the authors of textbooks. Finally the fundamental constants in Appendix A are 15 years out of date: they are the 1973 rather than the 1986 recommended values. I also have some criticism of the choice and arrangement of material. Like many before him, this author persists in using wavelength A to label spectral lines and the regions of the spectrum, when wavenumber F = l/A shows up the relation to energy formulae so much more vividly. Modem instruments produce beautiful spectra, on a linear wavenumber scale, yet some of those reproduced in this book are antiquated (e.g. p. 75 and p. 76); the author could so easily have included many beautiful spectra to illustrate his points. The treatment of rotation and vibration-rotation spectra is weak compared to the rest of the book (one suspects that this is not the author’s field); the chapter on lasers contains no mention of CO,, CO, colour centre, diode, or difference frequency lasers in the infrared, nor of excimer lasers, frequency doubling, and Raman shifting, to access the UV; the Nd-Yag laser just barely gets mentioned. On the theoretical treatments, which one senses to, be the author’s strength, the book invites comparison with Herzberg’s famous volumes, in which much of the
VIBRATIONAL
104
same material is covered -with greater clarity in my view. Having made my criticisms, I want to welcome this book. There are few enough authoritative treatments of this subject in any form, and this book gives a correct feeling for the theoretical base of the subject and its importance in quantum chemistry. I hope that it runs to a second edition, which -with revisionsmight become a first class textbook. I. Mills University of Reading Reading, Great Britain D.J. Gardiner and P.R. Graves (Eds.), Practical Raman Spectroscopy, Springer Verlag, Berlin, 1989 (ISBN 3-540-50254-8). viii + 157 pp. Price DM 78.00. Although this is a slim volume, only 157 pages, it is an excellent book and a very welcome addition to the relatively scarce Raman literature. It is useful to both the beginner with elementary, but well written material and to the practicing spectroscopist as a quick reference book. The hope of the editors was to “provide a source of on-hand technical support and data for the practicising Raman spectroscopist in the laboratory.” This they have done. One hopes the the next edition will be expanded and more comprehensive. The introduction is very elementary, but a nice discussion of classical theory and quantum theory of Raman scattering. It would have been a good idea to include some elementary theory of SERS enhancement in this chapter. George Turrell’s chapter on Raman sampling is exceptionally well written. Although the author appologizes for not being able to include everything within the scope of a small book, we find many useful things which are not readily found elsewhere. He presents a selection of the most important developments in sampling different types and morphologies of samples; and he provides good basic physics and mathematical treatment behind different methods. It is this aspect we find very useful and refreshing. Instrumentation for Raman Spectroscopy is a
SPECTROSCOPY
good review chapter on instrument design. This chapter could be improved by adding more rigorous physical optics/mathematical treatment of the issues involved. The section on detectors and gratings is particularly well written with a wealth of information in it. We disagree with the statement of p. 71 that “it is not normally possible to use them (intensified detector arrays) for studying bands close to the exciting line.” With well designed spectrometers, stray light is not a problem and even with solids one can approach quite close to the excitation line. Pierre Graves’ chapter on calibration and data handling is a good review, and we are particularly glad to see the introduction of the maximum entropy method of image reconstruction. The chapter on non-standard physical and chemical environments is very well organized into convenient sections on high temperature, low temperature, high pressure and special chemical environments. It is a very good, quick reference and starting point when looking into particular experiments. The chapter on Raman microscopy by J.D. Louden is especially welcome. This area has emerged as a major development in Raman spectrocopy in the last several years. In addition to covering the historical background and basic principles of micro-Raman, there is considerable information of a very specific and practical nature. The examples are quite good and include temperature and pressure techniques, illumination techniques, polarization ratios, spatial resolution and spatial filtering and Raman imaging and mapping. Recent promising developments in Hadamard transform Raman imaging by P. Tread0 and M. Morris at the University of Michigan could have been included in the section discribing Raman imaging and mapping. Actually, the major criticism of this book is the quality of the binding (paperback). After only a few times going through it, the book literally fell apart. That is a shame, because anyone in Raman spectroscopy will want to use it frequently. M.A. Hazle M. Mehicic B. P. Research International Cleveland, OH, U.S.A.