# Book Review Introduction to Theoretical Organic Chemistry and Molecular Modeling. By W. B. Smith

код для вставкиСкачатьBOOKS tion used in the book is for the reader to decide. It remains to be seen to what extent the proposed new approach will be taken up in research and teaching. Bernhard Neumiiller Fachbereich Chemie der Universitat Marburg (Germany) Introduction to Theoretical Organic Chemistry and Molecular Modeling. By W B. Smith. VCH Publishers, New York, 1996. 192 pp., hardcover DM 89.00.--ISBN 1-56081-937-5 Computer programs for quantumchemical calculations are becoming increasingly user-friendly, and consequently chemists with limited theoretical knowledge are using them more and more often. It is all too easy for non-theoreticians to be misled by the suggestive power of the attractive graphics. so that they overvalue the information content of the results that the black box turns out with so little effort. For these users there are only three possible ways out of this dilemma: 1. leave well alone; 2. work in collaboration with colleagues; or 3. acquire the necessary theoretical knowledge by private study. This book by W. B. Smith is intended to help with the third alternative. It is certainly a welcome development when an attempt IS made to present theoretical organic chemistry at such a level that it can be understood by most nonspecialists. Although there are many excellent books on the quantum-mechanical fundamentals of chemistry, few of these offer help in the practical application of theoretical methods. In accordance with the title of this book, the author’s idea is first to introduce the reader to the theoretical fundamentals of quantum chemistry (qualitative MO theory), then in the second part (from Chapter 7 onward) to treat the most commonly used theoretical methods, and this approach is undoubtedly correct. However, it must be said at the outset that neither the first nor the second part is suitable as a student textbook. The choice of subject matter and the strong emphasis placed on the Huckel theory give cause for concern. It is true that in a treatment of such a complex topic as this within a mere Angebv. Clwn. hi.Ed EngI. 1997, 36, No. 12 192 pages, one has to be prepared to accept some compromises. Nevertheless, the mathematical derivations must be errorfree, understandable, and entirely consistent. This book contains so many errors, loose and careless statements, and lapses from rigor in the physical arguments, that a newcomer to the subject is at risk of failing to follow the discussion o r getting an incomplete picture. A few examples will illustrate this. The first is the derivation of the Schrodinger equation in a few steps on pages 2 and 3. The transition from classical mechanics to quantum mechanics is made, without further explanation, by replacing the momentum in the classical expression for the total energy by the corresponding quantum-mechanical operator, then multiplying the expression by a wave function which appears from nowhere. Arguments of this kind d o not help towards an understanding of the quantum theory. The symbols used for variables are not always consistent. On page 3 the symbol \i/ is used for the total wave-function, whereas on page 4 it represents the basis orbitals. Later we find that Y is used for molecular orbitals, whereas in the description of the S C F methods (p. 109) Y represents the total wave-function and \i/ a molecular orbital. As the text contains no mention of the changes in meaning, the reader unfamiliar with the theory will inevitably be confused. In the mathematical formulas, vectors are never clearly distinguished as such, and operators and matrices only occasionally. The lack of care in the text also appears in statements that are difficult to understand or even misleading. On page 30 alone we find that a summation index is missing from each of the equations (2.17) to (2.22), a bracket is missing in the example of butadiene, and in Equation (2.22) the indices on the two sides of the equation d o not agree. Often the symbols in the figures and equations d o not correspond to those in the text; for example, on pages 32 and 33 the coefficients are denoted by ‘a’ in the figure but by a in the text, and on page 95 the symbol for the basis orbitals is 4 in Equation (6.23) but cp in the text immediately below. On page 119 the method described here for minimizing the energy has little to d o with the Newton-Raphson method to which the author refers. Also the general discussion about mathematical methods C; VCH Verla~gesrllsrhafimbH, D-69451 Weinheim, 1997 for energy minimization is scarcely understandable and will convey little to the reader. The explanation of CISD in Section 7.4 is simply incorrect. “CI-singles,doubles” is not, as stated here, a linear combination of the ground state Slater determinants and the first and second excited states. There are also many mistakes in the non-mathematical part of the book. In Chapter 6 (pericyclic reactions, etc.) even the first reaction equation (6.1) defining pericyclic reactions is incorrect. In the Claisen rearrangement shown here, allylphenyl ether rearranges to give o-hydroxystyrene. In Equation (6.2) the second reaction arrow has below it nv instead of hv, and hv is missing from Equation (6.3). The claim that “. . . no stable ring systems containing an odd number of changes in fi can exist . . .” is presumably a guess. Again, it is incorrect and misleading to state (on page 91) that for a qualitative treatment of the stereochemistry of photochemical reactions it is unimportant whether a singlet or a triplet state is present. The list of errors and examples of slipshod writing could be continued. The poor quality of the figures is evident even on first opening the book (the Mobius strip on p. 88 and the energy hypersurface on p. 150 are two interesting examples). Leaving aside esthetic considerations, many of the figures are not very suitable for explaining the matters to which they relate. For example, the connection between the orbital diagram (6.20) and the reaction equation (6.18) would only be apparent to a specialist. Due to the large number of mistakes and examples of careless writing, the absence of any indications as to the previous knowledge assumed, and the disjointed and unclear style in which the arguments are presented, the reader unfamiliar with the subject is unlikely to learn much from the book. Moreover, the price seems unjustifiably high for a textbook of 192 pages. Perhaps the printing error on the first page-“testbook” in place of textbook-is no ordinary mistake but a Freudian slip. Raiizer Herges Institut fur Organische Chemie der Technischen Universitlt Braunschweig (Germany) 0570-0833/97/3612-13553 I7.50f .50;0 1355

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