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Book Review Optical Circular Dichroism. Principles Measurements and Applications. By L. Velluz M. Legrand and M. Grosjean transl. by J

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Spectroscopy in the far infrared for the analysis of high
polymers, resins, monomers, and plasticizers is recommended
by D . Hummel to supplement the data from spectroscopy in
the middle infrared. Spectra in the far infrared (between 700
and 250 cm-1) are particularly sensitive towards alterations
in intra- and intermolecular forces and are therefore valuable
for examining the conformations and crystallinity of high
polymers. Although strongly polar and crystalline materials
generally have many relatively strong absorptions in the far
infrared, amorphous resins often give spectra with hardly
any prominent features. Since light in the far infrared is
scattered less by turbid samples than that in the middle
infrared, the techniques for measuring far-infrared spectra
are ofter much simpler. / Kunststoffe 55, 102 (1965) / -HI.
[Rd 296/505 IE]
Optical Circular Dichroism. Principles, Measurements, and
Applications. By L. Velluz, M. Legrand, and M. Grosjean,
transI. by J. MacCordick. Verlag Chemie GmbH., Weinheim1Bergstr. (Germany) and Academic Press, New YorkLondon 1965. XII+247 pp., 149 figs., 10 tables, linen
DM 40.- (about $ 10.00).
The measurement of optical circular dichroism, i. e. the difference in absorption of left-hand and right-hand circularly
polarized light by optically active compounds, is one of the
most modern optical methods of investigation. Circular dichroism yields valuable information about the configuration
of organic molecules having a chromophore in the vicinity of
their center of asymmetry. Some years ago L. Velluz, M. Legrand, and M. Grosjean developed a n apparatus with which
dichrograms can be measured as conveniently and rapidly as
ordinary absorption spectra, thus making the method accessible to the organic chemist interested in configurational
problems. The authors have made a further significant contribution with this first monograph o n the subject.
One of the two introductory chapters contains a comparison
of circular dichroism and optical rotatory dispersion. The
experimentally easier, and therefore previously applied,
measurement of the rotation of plane polarized light as a
function of wavelength also gives information about the configuration of optically active compounds. Whereas measurable dichroism occurs only in the region of absorption of the
responsible chromophore, optical rotation extends well
beyond this range, although with diminishing magnitude.
This leads to specific differences which makes the two
methods complementary. The authors justifiably regard the
simpler form of the dichrograms as a n advantage in the analysis of the experimental data. In compounds having several
chromophores near the asymmetric center, or a chromophore
with several absorption bands, a detailed investigation and
assignment of the separate effects is often possible only with
the aid of circular dichroism. On the other hand, measurement of rotatory dispersion is indispensible for configurational studies on compounds which absorb below 220mp
and into which no chromophore absorbing at higher wavelengths can be introduced.
Readers primarily interested in the application of the method
to structural problems may find the following chapter (58 pp.)
somewhat too detailed and theoretical. For circular dichroism it is, however, particularly worthwhile to learn more
about the principles and selection of the method of measurement, since considerable difficulties in instrumentation had to
be surmouted. It would, however, be desirable if in a later
edition a separate chapter could be added here on measuring
techniques, cells for kinetic and low-temperature measurements, possibilities to enhance the fine structure, etc.
The main part of the book (105 pp.) is devoted to the application of circular dichroism. Optically active compounds containing the ideally suited carbonyl chromophore - mainly
steroid ketones - are described first in this section. After a
theoretical analysis of the carbonyl chromophore, a clear
explanation of the octant rule is given. The application of
this rule to determinations of absolute configuration is demonstrated on systematically ordered groups of steroid
ketones and extended to compounds in which the keto group
is not in a saturated six-membered ring. An advance for the
theory and applications of circular dichroism is the introduction by the authors of the normalized dichrograms, in
which all ordinate values are divided by the maximum height
of the curve. The shape and position of these dichrograms are
characteristic for a given combination of chromophore and
asymmetric center and independent of the rest of the molecule. - Next alcohols, amines, and carboxylic acids, which d o
not absorb above 220 mi", and which were investigated after
conversion to derivatives absorbing at longer wavelengths,
e.g. xanthates, nitrosamines, and acylthioureas are discussed.
I t is then shown with cobalamines, anthracyclinones, peptides,
and polynucleotides, that successful configurational investigations of natural products containing a complicated chromophore are possible with the aid of circular dichroism. The
anthracyclinones are also a n example of measurements o n
compounds of low optical activity and very high extinction
coefficients. - It is remarkable that most of the numerous
measurements published to date have been made on a n apparatus described by the authors. The next chapter (10 pp.)
describes the effects of concentration, temperature, and solvent on optical circular dichroism in three sections. Some
references to application to kinetic measurements, analysis
of mixtures, and measurements at low temperatures are also
concealed under these headings. The book closes with a brief
presentation of the present status of the molecular theory of
optical activity and with a valuable appendix listing wavelength and intensity of the dichroism maxima of over 400
Configurational analysis using optical circular dichroism is
becoming increasingly important through new developments
in the elucidation and synthesis of optically active compounds.
As the first monograph o n the subject, and with the originators of the method as authors, the book hardly needs recommendation. It is very welcome that the publishers have presented it in English and thus made it immediately accessible
to a wide range Of readers. B. Frunck
[NB 4241269 IE]
Polycyclic Hydrocarbons. Volume I. By E. Clar. Academic
Press, London-New York, and Springer Verlag, BerlinGottingen-Heidelberg 1964. 1st Edit., XXVIII 488 pp.,
80 figures, 8 tables, linen, DM 70.- (about $17.50).
Since the appearance of the well known monograph by E.
Clar o n polycyclic aromatic hydrocarbons in 1952, this field
has undergone vast material and theoretical developments.
Almost 40% of the polycyclic systems known a t present have
been synthesized within the past 12 years. This new English
monograph is therefore much larger than the previous edition and appears in two volumes. The first volume contains
general chapters on the chemistry, physics, and biological
importance of aromatic hydrocarbons and a systematic discussion of cata-annellated systems.
Although the text covers the synthesis, properties, spectra, and
biological activities of all the hydrocarbons described in the
literature up to 1963 and thus gains the informational
value of a work of reference, Ctar's own contributions are
placed in the forfront of the theoretical chapters. In the preface, he states that the book is written " . . . to present the facts
in a simple and clear order . . . but it does not present a comAngew. Chem. internat. Edit. 1 Vol. 4 (1965)
1 No. 10
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measurements, circular, dichroism, book, optical, application, legrand, vellus, grosjean, review, transp, principles
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