# Book Review Bonding and Structure Structural Principles in Inorganic and Organic Chemistry. (Series Inorganic Chemistry. Series editor J. Burgess.) By N. W. Alcock

код для вставкиСкачатьA chapter is devoted to a thoughtful analysis of decarbonylation reactions, the reverse of carbonylation processes. This transformation is useful in certain situations, and clearly more work is required in this area. The final chapter provides experimental procedures for the synthesis of many of the catalysts described in the book. This is a useful contribution, as is the description of methodology for the recovery of metals. In conclusion, this impressive book is well-written, enjoyable to read, and will be of genuine value to chemists. Cathleen Crudden, Howard Alper University of Ottawa Ottawa (Canada) Chemometrics. Applications of Mathematics and Statistics to Laboratory Systems. By R. G . Brereton. Ellis Horwood, Chichester, 1990. 307 pp., hardcover $76.50.--ISBN 0-13131 350-9 The purpose of this monograph, which is published as an independent volume in the “Ellis Honvood Series in Chemical Computation, Statistics and Information”, is to familiarize the experimental chemist with the capabilities and advantages of chemometric methods. The book proceeds mainly by using simple examples to briefly explain the principle of each of the chemometric methods described, then illustrating how they can be applied to real chemical and analytical problems. This approach has the advantage that the emphasis is on understanding the mathematical and statistical methods used. In describing computer-based methods the author frequently gives details of the wide choice of software that is commercially available, and is in most cases adequate for the purpose. A brief account of the development of chemometrics is followed by an introductory survey of up-to-date literature on chemometrics. The following six chapters describe, in a clearly organized division of subject matter, the most important chemometric methods and their applications. The chapter on experimental design describes the use of sequential methods such as simplex optimization, factorial plans, multilinear regression methods and variance analysis for the quantitative modeling and optimization of chemical experiments. Next the author describes both well-established methods (control card techniques, the cusum method, autocorrelation analysis) and newer methods (the autoregressive moving average method, the variogram, the Kriging method and the Nyquist frequency) that are used as aids in investigating time series in chemistry and for dealing with the complicated problem of representative sampling. Chapter 4 describes the many different methods for selecting and optimizing the conditions for analyses, such as principal component analysis, information theory, classification procedures, simplex methods, and Fourier and Hadamard transformations. The next two chapters are concerned with the application of univariate and multivariate methods in signal processing. Here there is some overlapping with topics in the previous chapter (e.g. Fourier transformation and principal component analysis), which is an unavoidable consequence of the wide range of uses of chemometric methods. Techniques described under the heading of univariate signal processing include moving average calculations, deconvolution of signals and Kalman filtering. The discussion of factor analysis as a tool for multivariate signal processing omits to give details of the estimation of communalities; however, Angew. Chem. I n r . Ed. Engl. 31 (1992) No. 5 6 there is a brief description of the modern method of target transformation factor analysis. In the section on multivariate calibration some important regression methods using latent variables, such as principal component regression and PLS regression, are mentioned but only described very briefly. The final chapter, which deals with pattern recognition, includes comprehensive descriptions of unsupervised learning methods, especially algorithms for cluster analysis, and the supervised learning methods using either “hard” (linear discrimination analysis, linear learning machine, K nearest neighbors) and “soft” (SIMCA) techniques, as well as “fuzzy” methods. The user will need to supplement the reading of the short appendix on important mathematical operations by also studying appropriate monographs on mathematical statistics. The appendix does not deal with the use of “robust” statistical methods. The typography is relatively free of errors, apart from a few exceptions (e.g. Equation 3.5 and Table 5.20), and is very clear. This monograph, with its clear layout of subject matter and the easily understood and well chosen examples of applications in chemistry and analysis, offers a good basic grounding for the experimental chemist who wishes to become involved in chemometrics; also readers who already use mathematical and statistical methods in their area of work will find here new ideas for applying chemometric methods. Jiirgen Einax Institut fur Anorganische und Analytische Chemie der Universitat Jena (FRG) Bonding and Structure: Structural Principles in Inorganic and Organic Chemistry. (Series: Inorganic Chemistry. Series editor: J; Burgess.) By N . u! Alcock. Ellis Horwood, Chichester, 1990. 321 pp., hardcover $ 50.95.--ISBN 013-465253-3 The introductory remarks in a book on chemical bonding and structure can provide a very good indication of its underlying philosophy; here, in a chapter entitled “The Evidence”, the author clearly states his position: all that we require to know are the positions of the atoms in space and the resulting total energy. In the first forty pages the reader is given a good brief survey of the experimental methods whereby structural information can be obtained (X-ray diffraction, NMR, IR, electron diffraction, neutron diffraction, etc.) and of the sorts of structural phenomena that can appear. Already one becomes aware of two things: 1) crystal structures dominate the discussion from the start, and 2) quantum chemistry, which has now developed into a very reliable method for determining molecular structures and one that can no longer be overlooked, is here ignored. Moreover, the author fails to keep to the promise made in the title, as the book is mainly concerned with inorganic solids. In a 100-page chapter entitled “Ideal Bonds” the properties of metallic, ionic and covalent bonds are described. The description of the underlying quantum mechanical principles is extremely brief and lacks clarity. The LCAO concept is dismissed in a few lines. In discussing the stationary state wavefunctions of hydrogen the real and complex representations are mixed up. The 1s wave function is given in Equation (l), i,h(r) = 2a0 - 6.5 exp(- riao) VCH Verlagsgesellschaft mbH, W-6940 Weinheim. 1992 0570-0833/92/0505-0663 $3.50+ .ZSjO (1) 663 and this is even emphasized by putting it in a frame. One of the d functions, although correctly drawn, is thereafter wrongly described as d:. How could this possibly lead to a conical nodal surface? The molecular cationic form of hydrogen is first written as H:, but then appears for several pages as H:. Also printing errors of all kinds are scattered through the text. We find, again within a frame, the statement: “The probability of finding an electron at a given point is given by t+h2”. Thus no distinction is made between probability and probability density, and as a consequence the significance of the volume element dv is completely ignored. The tetrahedral structure of methane is explained in terms of hybridization, with the remark that “One electron can easily be promoted from the 2s to the 2p level”-no mention is made of the energy needed for this process. Is an energy of 97 kcalmol-’ small?-and if so, relative to what standard? Next the molecular orbitals of methane are wrongly shown, and it is stated that the LUMO is threefold degenerate. Space does not allow all the other inconsistencies in this chapter to be listed. After describing several types of double bond and the VSEPR model, Hund’s rule is stated in such a confused way that one recognizes it only from the heading above the frame; thus we read: “Electrons occupy separate orbitals rather than being paired up” and “The electrons are aligned parallel rather than antiparallel”. What remains here of the precise formulation given by Hund in 1927, which leads directly to unambiguous statements in spectroscopy? Finally it is even claimed that the bent structure of the NO, radical is a consequence of the Jahn-Teller effect. Registered mmes, rrodemarks, etc. used in rhis journal. even when nor marked a such, are not It comes as a relief to find that the second part of the book is entitled “Real Bonds and Real Compounds”. Here again metals and alloys occupy a central position, but hydrogen bonds and donor-acceptor bonds are also described. In the second of these the “printer’s devil” has ensured total confusion by showing, in contradiction of the text, a double occupancy for the acceptor orbital on the boron atom in the key figure to illustrate the B-N bond. Transition metal complexes are described in detail, but the reader will fail to gain an understanding here of the Jahn-Teller effect, since no distinction is made between the concepts of configurations and states. The reader can skip over a whole section on main-group elements, as it reintroduces antiquated devices that have long since been thrown out (the use of d-functions for main-group elements). The same also applies to the section on aromaticity, which is based on Huckel orbitals and completely ignores the developments of the past ten years. For which readers can this book be recommended? Certainly not for the chemistry students for whom the author intended it. Instead the last 50 pages, which are the book’s saving grace, will provide the advanced specialist in solid state chemistry with some information on complex crystal structures, ceramic materials, ionic conductors, ferroelectric materials, nonlinear optics, magnetic interactions, superconductors and semiconductors. Rudolf Janoschek Institut fur Theoretische Chemie der Universitat Graz (Austria) 10 be considered unprotected by law. Q VCH VerlagsgesellschaftmbH, D-W-6940 Weinheim, 1992. -Printed in the Federal Republic of Germany by Konrad Triltsch Druck- und Verlagsanstalt WCrzburg. All rights reserved (including those of translation into foreign languages). No part of this issue may be reproduced in any form -by photoprint, microfilm, or any other means -nor transmitted or translated into a machine language without written permission from the publishers. Only singlecopies ofcontributions, or parts thereof, may be made for personal use. This journal was carefully produced in all its parts. Nevertheless, authors, editors, and publisher do not warrant the information contained therein to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details, or other items may inadvertently be inaccurate. Valid for users in the USA: The appearance of the code at the bottom of the first page of an article (serial) indicates the copyright owner’sconsent that copies ofthe article may be made for personal or internal use. or for the personal or internal use of specific clients. This consent IS given on the condition, however, that the copier pay stated per-copy fee through the Coypright Clearance Center, Inc. (CCC), for copying beyond that permitted by Sections 107 or 108 of the U . S . Copyright Law. This consent does not extend to other kinds of copying, such as copying, for general distnbution, for advertising or promotional purposes, for creating new collective works. or for resale. For copying from back volumes of this journal see ‘Permissions to Photo-Copy: Publisher’s Fee List’ of the CCC. Editorial oflice: Postfach 10 11 61, D-W-6490 Weinheim. Federal Republic of Germany, Telephone (06201) 60 23 15, Telex 465 516 vchwh d, Telefax (06201) 602 328, E-Mail ZI6@DHDURZ2 in Earn Bitnet. Editor: Peter GBIirr Associate editors: R. H . Schmidt-Radde, K. J Schneider, A . Srimson. Editorial assistant: E. Schweikarl Publishen: VCH Verlagsgesellschaft mbH. (Managing Directors. H a m Dirk Kiihler, Dr. Kudheinz Kiipfer), Pappelallee 3, W-6940 Weinheim, Federal Republic of Germany. Advertising oflice (Advertising Manager: R. J. Roth): Postfach 10 1161, D-W-6940 Weinheim, Federal Republic of Germany, Telephone (06201) 6061 36, Telex 467155, Telefax (06201) 606156. 664 0 VCH Verlagsgeselkchuft mbH, W-6940 Weinheim,1992 0570-0833/92jOSO5-0664 $3.50+ ,2510 Angew. Chem. I n f . Ed. Engl. 31 (1992) No.5

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