вход по аккаунту


Book Review Two-Dimensional NMR Methods for Establishing Molecular Connectivity. A Chemist's Guide to Experiment Selection Performance and Interpretation. By G. E. Martin and A. S

код для вставкиСкачать
After two further chapters on substituent effects, hydrogen bonding and complex formation, the chemical reactions
are then treated in a total of 435pages. The chapters by
S . Oae and Y. Uchida and by G . H . Posner on a-sulfinyl and
cr-sulfonyl carbanions as useful CC bond-forming reagents
are of particular interest for the synthetic organic chemist;
these reagents have proved to be extremely useful for asymmetric syntheses. Other chapters that are mines of information on reactions useful for preparative work are those on
rearrangement reactions ( S . Bravermunn, 94 pp.)-here one
thinks of the important Pummerer reaction-on reduction
reactions (J. S . Grosser?, 43 pp.), which includes a description of the interesting Julia reaction for preparing carbonyl
compounds from sulfones, and on sulfinyl and sulfonyl radicals (C. Chatgiliuloglu, 34 pp.). The last of these chapters
contains, for example, (though rather inconspicuously) the
SO, extrusion reaction which is important in cyclophane
The numerous literature references extend up to 1987 in a
few chapters, but in general only up to 1986; the long time
required to produce such a book makes it very difficult to
achieve a degree of topicality better than this.
This volume is, of course, essential to every library. Because of its exceptionally high quality I would also like to
recommend individual organic chemists (not only sulfur
chemists) to buy it, but of course the price is almost prohibitive.
Jiirgen VoJ [NB 947 IE]
Institut fur Organische Chemie
der Universitat Hamburg (FRG)
Computational Chemistry. An Emphasis on Practical Calculations. (Series: Studies in Physical and Theoretical Chemistry, Vol. 56). By M . 0.Johnston. Elsevier, Amsterdam
1988, xviii, 680 pp., hard cover, HFI 245.00/paperback,
HFI 245.00. -ISBN 0-444-42962-X/0-444-42963-8
This book is apparently based on the author’s lecture
notes of an introductory course on data processing for chemistry students. Its contents are arranged in a clear didactic
sequence as follows: 1) basic considerations and concepts in
electronic data processing, with the emphasis on personal
computers (algorithms, structured programming, user-friendliness, sorting programs, text processing, preparation of tables, data banks, main-frame computers and networks, basic
PC equipment, programming languages); 2) various useful
application-orientated programs in analytical and numerical
mathematics (factorization of rational functions; Horner
scheme; useful formulas for differentiation and angular
functions; complex numbers; matrices, determinants, vectors, systems of linear equations); 3) programming numerical and graphical problems of chemistry in BASIC (graphical representation of 2D and 3D functions, contour plots,
simple molecular graphics, some special functions, searching
for stationary points, numerical differentiation and integration, Monte-Carlo integration, matrix routines, diagonalization, differential equations, curve-fitting, regression analysis, minimization); 4) an extensive collection of useful
programs for the chemist, varying greatly in length (some up
to 2000 lines in length, including a molecular graphics program, a graph-plotting package, a matrix package, simplex
minimization, a fast Fourier transform program, a titration
curve program, and NMR spectrum simulation). Each section concludes with questions to test the reader’s understanding and a few exercises.
The text is written in an easy, one might even say casual,
style, such as one might use when lecturing to students so as
Angew. Chem. Inr. Ed. EngI. 28 (1989) No. 8
to hold their attention. This is indeed necessary in the early
part of the book, which sometimes contains long-winded
general observations expressed in sentences of little factual
content (“textbooks are an invaluable source of basic information”; “select the best method for the problem at hand”;
“write expressions so that it is best for the actual calculation”).
The teaching strategy of the book is based on illustrating
the methods and enabling the reader to learn and understand
by applying them himself. The theoretical background to the
methods used and the programs listed is explained later
(though not always adequately). This very pragmatic approach should please chemists who are not keen on theory,
but it is not to everyone’s taste.
The author expresses the view that some first-hand programming experience is needed in order to make effective use
of the computer and pre-written programs (however, the
assertion that “if you can program, the computer is your
servant; otherwise you are the computer’s slave” is rather an
exaggeration). While it is true that programming experience
is best gained by working through examples of well-written
programs, the reproduction in the book of many pages of
computer code appears of limited value. Would it not have
been possible to supply a diskette to go with the book? Many
of the comments reflect the personal tastes of the author too
strongly, and should be read with a measure of skepticism
(“FORTRAN is not suitable for use with microcomputers”;
“In going from microcomputers (i.e. PCs) to minicomputers
we gain little, if anything”; “The mouse is one of the silliest
inventions which has ever captured the fancy of anyone”).
The book contains much of value for a good introductory
course, but there is not much on the subjects of data banks
and text processing. Incidentally, it has been prepared using
a very basic word-processing system (no special characters,
no line justification, no word breaks); also the typed pages
are not free of typographical errors. Students, for whom the
book is no doubt intended, will surely not pay the horrendous price for this level of quality. Comparable books are
available at considerably lower prices.
K H . Eugen Schwarz [NB 959 IE]
Institut fur Theoretische Chemie
der Universitat-Gesamthochschule Siegen (FRG)
Two-Dimensional NMR Methods for Establishing Molecular
Connectivity. A Chemist’s Guide to Experiment Selection,
Performance and Interpretation. By G. E. Martin and A . S.
Zektzer. VCH Verlagsgesellschaft, Weinheim/VCH Publishers, New York 1988. xviii, 508 pp., hard cover,
DM 126.00.- ISBN 3-527-26858-703-5/0-89573-703-5
In view of the flood of books on two-dimensional NMR
spectroscopy during recent months and years, the appearance of each new book prompts one to ask whether it has a
particular appeal, either with respect to the range of topics
covered or the readership to which it is addressed. The book
“Two-Dimensional NMR Methods for Establishing Molecular Connectivity”, by G. E. Martin and A . S . Zektzer, published by VCH Verlagsgesellschaft, does in fact display such
a speciai quality. It concentrates on a clearly defined subject
area, giving a very detailed account of two-dimensional
pulsed NMR methods for revealing connectivities of the two
elements hydrogen and carbon, the main emphasis being on
applications to organic natural products with molecular
mass less than 1000. In NMR spectroscopy connectivity information is, in chemists’ language, information about the
molecular constitution of a compound. Questions relating to
Q b T t i Verlagsgesellschafz mbH, 0-6940 Weinheim. 1989
0570-0833j89j0808-1071$ 02.S010
stereochemistry or conformation are therefore excluded
completely from the discussion. In accordance with this,
methods for measuring such structure-related N M R
parameters as coupling constants or cross-relaxation rates
are not included.
The organization of the book falls clearly into seven chapters. In the introductory chapter the principles of 2D N M R
spectroscopy are briefly described, and practical information
and advice is given on the processing of the data, presentation of the spectra and planning of experiments (including
pulse width calibration). Chapter 2 is devoted to H-H connectivities, and includes a detailed description of the basic
COSY experiment and six variants of it. The chapter concludes with an account of multiple quantum N M R spectroscopy. In Chapter 3 methods for determining H-C connectivities are described. A full account of all the methods. from
the first selective SPT experiments through to the most sensitive present-day pulse sequences with ‘H detection, is given.
Chapter 4 is devoted to relayed experiments, including
homo- and heteronuclear, single and multiple relayed experiments, and the related TOCSY experiment. Chapter 5 then
deals with l3C-I3Cconnectivities, with a strong emphasis on
the INADEQUATE experiment. The latest variants with ‘H
detection are also treated. Finally, Chapter 6 presents spectroscopic problems of structure determination in organic
molecules, and solutions to these are provided in Chapter 7.
The main emphasis of the book is on the fifty or so pulse
sequences that are described. The discussion of these is supported by an excellent survey of the literature, with a comprehensive bibliography which covers not only the first publication on each pulse sequence and the modifications
subsequently introduced, but also many published applications. The authors give details of experimental conditions
which they have themselves tested and found to give good
results, and the majority of the spectra shown are their own.
In many of the examples spectra recorded on the same compound using different methods are shown and discussed in
order to compare the information given by each method.
This gives the user a valuable impression of the advantages
and disadvantages of the various methods. The descriptions
of the pulse sequences include explicit information on phase
cycles, although regrettably these are incorrect in some cases.
Readers must therefore be warned against using these pulse
sequences uncritically; instead they should compare them
with the original papers.
The book does not aim to give a rigorous theoretical understanding of the pulse sequences, and the reader who is
unfamiliar with “spin gymnastics” will experience some difficulty in understanding the discussions. Inevitably, therefore, certain expressions are used, such as “passive transfer”,
without their meaning being fully explained.
The numerous figures illustrating the techniques described
are an important feature of the book. However, it is incomprehensible why the labeling of the spectra is so sparse and
frequently illegible, often making the search for the spectral
details discussed in the text a laborious task. The poor quality and often inadequately small scale of the figures is especially annoying in Chapters 6 and 7 which contain the spectroscopic problems. Also cross peaks are sometimes missing,
so that one is forced to read the solution to the problem.
In summary it can be said that this book offers a detailed,
excellently researched and unbiased account of 2D N M R
methods for determining molecular constitution. For the
N M R practitioner it provides very useful information and
advice on planning experiments and interpreting spectra, illustrated by interesting examples from natural products
chemistry. One is willing to forgive the less than perfect
c) VCH Verlagsgesellschafr mhH. 0-6940 Weinherm, I989
quality of the figures and the errors that are probably unavoidable in view of the large amount of material included.
Christian Criesinger [NB 965 I E ]
Laboratorium fur Physikalische Chemie
der Eidgenossischen Technischen Hochschule
Zurich (Switzerland)
Activation Analysis with Charged Particles. Ellis Horwood
Series in Analytical Chemistry. By C. Vundecasteele. Ellis
Horwood, Chichester/Halsted Press, New York 1988.
171 pp., hard cover, $29.95. -ISBN 0-7458-0175-7/
0-470-21 204-7
In contrast to neutron activation analysis (NAA), charged
particle activation analysis (CPAA), mainly using protons,
but also deuterons, tritons, and nuclei of helium-3 and helium-4, has found little use up to now in elemental trace analysis; consequently it has no chance of becoming a universal
routine method. Nevertheless CPAA, which has very high
sensitivity, can be used as a complementary method with
NAA and other trace analysis methods in special types of
problems. It offers higher sensitivity than the other methods,
and also eliminates ambiguity in some cases, for determining
light elements such as H, Be, B, C, N and 0 down to ppb
concentrations, especially in ultra-pure metals and semiconductors. However, the acceleration of the particles for CPAA
requires very expensive equipment such as a Van de Grdaf
generator or a cyclotron (for protons and deuterons with
energies of 2 to 20 MeV), and sometimes causes complex
nuclear reactions which necessitate subsequent radiochemical separation. Consequently it has great disadvantages
compared with NAA and atomic spectroscopy for determining medium and heavy elements, e.g. in geochemical o r biological matrices, and only in rare cases is it sensible to use it
for such analyses.
The author of this first monograph on the theory, experimental requirements and applications of CPAA, who has
considerable practical experience in this field, is well aware
of the limitations of the method. About a half of the book is
taken up by general matters, including introductions to the
theoretical basis, descriptions of accelerators and irradiation
techniques, the relevant nuclear reactions and data on these,
and the procedures needed for calibration and avoidance of
errors. In the chapters that follow describing applications to
trace analysis, the practical importance of CPAA in each of
the areas covered is clearly reflected by the numbers of publications cited. The most important chapter, “Determination
of Light Elements”, has 85 references. That on “Determination of Medium and Heavy Elements in Metals and Semiconductors”- where irradiation by protons is still the most
important experimental method - has 42 references. “Analysis of Geological, Environmental and Biological Samples”
has 14 references, as does the more academic “Activation
Analysis using Heavy Ions”. In all the chapters the literature
up to the present date is covered very thoroughly and described in clear language, thus giving students, teachers and
those interested in using the method an excellent picture of
the capabilities of CPAA, although only a few experts will
ever be able to use the method in their own laboratories. The
main value of the book therefore lies in the information on
when it is appropriate to use CPAA, and where to turn for
help in such cases.
Giinther Tolg [NB 975 IE]
Institut fur Spektrochemie
Dortmund (FRG)
0570-0833jSSjOR0R-l072 $02.50/0
Angew. Chem. In[. Ed. Engl. 28 (1989) N o . 8
Без категории
Размер файла
304 Кб
two, dimensions, selection, connectivity, molecular, chemists, performance, method, interpretation, establishing, martin, experimentov, nmr, book, guide, review
Пожаловаться на содержимое документа