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New Theories for Chemistry. By Jan C. A. Boeyens

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Angewandte
Books
Chemie
Nanocrystals Forming Mesoscopic
Structures
By Marie-Paule
Pileni. Wiley-VCH,
Weinheim 2005.
330 pp., hardcover
E 139.00.—ISBN
3-527-31170-X
This book covers some of what is known
about a subtopic of nanotechnology—
the unusual superstructures that nanocrystals sometimes form. The nanocrystals are almost always coated with
organic ligands with polar head groups,
and these ligands, of course, strongly
affect the superstructures that form.
Different terms have been used in
the literature to describe these superstructures: mesoscopic structures, opals,
nanocrystal superlattices, three-dimensional self-assemblies, supracrystals, and
others.
The book is divided into 13 chapters
that cover what is known about selfassembly of inorganic and magnetic
nanocrystals, of metal nanoparticles in
solid matrices, self-assembly of anisotropic nanoparticles or mineral liquid
crystals, the collective properties of
these superstructures, and exploitation
of such structures for optical sensors and
lithography. The final chapter deals
briefly with shrinkage cracks that can
occur as a universal feature.
Of particular interest are several
chapters that deal with collective properties, especially dipolar interactions,
orientation of the easy magnetic axis,
unusual Raman and UV/Vis absorption
Angew. Chem. Int. Ed. 2006, 45, 5243 – 5244
spectra, reflectivity, electron spectroscopy, and photoemission. These intrinsic
collective properties are consequences
of the compact nanocrystal networks
(often fcc or hep), which lead to coupled
plasmon modes because of dipole–
dipole interactions, vibrational coherence, and electric fields arising from
local polarization. Collective plasmon
modes are also observed.
Although the title implies that the
emphasis is on self-assembled mesoscopic structures, actually a wide variety
of solid supports or matrices are also
covered: polymer frameworks, cellulose,
mesoporous silica, titania films, polymeric films, zirconia, microemulsions,
layered assemblies, etc.
Chapter 5 on “Three-Dimensional
Self-Assemblies of Nanoparticles” is
particularly interesting. Liquid colloidal
crystals, solid colloidal crystals, and twodimensional colloidal crystals are discussed. The triggers for aggregation/
coagulation are also discussed, and
include pH, hydrogen bonding, host–
guest interactions, van der Waals and
electrostatic interactions, and charge
transfer. Programmed assemblies that
are formed by ligated biological molecules, gel networks, and Langmuir–
Blodgett films are mentioned. Microgravity, shear flow, and temperature
gradients are also discussed as forces
that can be used to manipulate the
aggregations. Applications of these
assemblies are also described, and
numerous beautiful images are presented.
The term “mesoscopic” refers to
middle or intermediate structures that
nanocrystals tend to form, either spontaneously or under external influences.
This book offers a new look at this
rather new topic. It is by no means
exhaustive, but its table of contents and
subject index are thorough and helpful.
It contains a great deal of interesting
information, and it is surprisingly broad
in its coverage, which is due to the
interdisciplinary nature of the subject.
What is still missing, however, is an
understanding of self-assembly that
leads to geometric structures, such as
triangles, rods, wires, tubes, and a host of
structures that are often observed. Also,
there is a long way to go towards
understanding how one can produce
desired structures. This book is a good
beginning, with much more to come in
the future.
Kenneth J. Klabunde
Department of Chemistry
Kansas State University
Manhattan, KS (USA)
New Theories for Chemistry
By Jan C. A. Boeyens. Elsevier Science, Amsterdam
2005. 279 pp.,
hardcover
E 155.00.—ISBN
0-444-51867-3
New Theories for Chemistry—an
appealing title for a book of nearly 300
pages, which immediately aroused my
curiosity. The table of contents also
raised my expectations and hopes, but
does this book meet these expectations?
In my opinion it falls a bit short of the
goal.
For Boeyens the fundamental problem in chemistry is to “reconcile the
consistent classical theories in chemistry
with the concepts of quantum mechanics”. He argues that the Bohmian formulation of quantum mechanics “probably holds the key to the development of
a theory of chemistry, soundly based on
quantum theory and relativity”. Symmetry arguments and number theory
also feature prominently in Boeyens=
underlying theme.
In this light, the seven chapters of
the book cover symmetry laws of nature
and mathematical structures in chemistry, the basics of Bohmian mechanics,
the structure of the electron and molecules, chemical concepts (valence states,
electronegativity, chemical bonding,
etc.), and reflections about space–time
geometries. Within the various chapters
one can find thought-provoking
approaches that are based on less traditional concepts. Specific enlightening
2 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5243
Books
examples include an appealing numbertheory approach to the mass numbers of
stable nuclei, an alternative interpretation of molecular conformations based
on Bohmian mechanics, and speculations about higher-dimensional space–
time geometries (e.g., five-dimensional
Kaluza–Klein theory). Although these
individual tiles have their particular
charm, Boeyens provides unfortunately
only a little assistance towards the
assembly of a complete mosaic.
This difficulty may arise, to some
extent, from the composite of materials
that forms the book: five out of seven
chapters are reworked review articles,
whereas a sixth chapter builds upon
Boeyens=s earlier book entitled The
Theories of Chemistry. The word “new”
in the book=s title is perhaps meant in
the sense “A New Book on Theories for
Chemistry”, as both Bohmian mechanics and Kaluza–Klein theory date back
to the middle or beginning of the last
century.
The question of what is the intended
audience for this monograph arose
repeatedly while reading the book, and
even the preface does not provide an
answer. The first chapter requires
knowledge in relativistic mechanics
and field theory, and readers lacking
the corresponding background will
quickly feel overwhelmed. Those equipped with this knowledge will almost
certainly have already been exposed to
Noether=s theorem and symmetry
breaking, and will therefore gain very
little. Chemists are, on average, more
5244
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likely to belong to the first category of
readers, and will instead turn to the
more chemistry-orientated chapters of
the book. In these parts they will, for
example, encounter attempts to describe
the (often varyingly defined) valence
state by compressed atomic states,
whose energy could provide a foundation on which an absolute electronegativity scale might be built. Readers will
become familiarized with Boeyens=
interpretation of molecular conformations and molecular structure within the
framework of Bohmian mechanics, in
which he identifies the electron=s angular momentum as a key quantity. In a
resolute and unconventional style,
Boeyens introduces these concepts,
strongly criticizing and sometimes refuting the traditional viewpoints. This
approach is not always conducive to
the adoption of new ideas, particularly
when deviating from standard paradigms. One such idea, with which I
strongly disagree, is the purported
equivalence between chirality and time
flow, as described in the fifth chapter.
The author at times does not take the
opportunity to fully elucidate and critically discuss his concepts.
Some parts may provide a vague and
potentially misleading impression for
the reader. However appealing it may
seem, at first sight, that in Bohmian
mechanics the classical limit corresponds to h ! 0 (or h/m ! 0), leading
to a seemingly vanishing “quantum
potential” and apparently to the classical Hamilton–Jacobi equation, Rosen
2 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
(1964), Cohn (1972), and others have
shown that one has to be more cautious
when considering the classical limit.
Given that the Bohmian formulation
leads, according to Boeyens, to “a radically different interpretation” of quantum mechanics, and plays such an
important role for his theoretical concepts, I would have expected at least a
reference to these difficulties. I encountered a similar experience with the
introduction to Kaluza–Klein theory
and speculation about other models.
Potential problems of the models, such
as conflict with experimental limits on
the number of extra dimensions or
possible new paradoxes, are not discussed. As such, the models seem
appealing, but it is not clear to what
extent they can survive rigorous tests.
For my taste, it would have been beneficial to draw here a clearer line between
fact, interpretation, and speculation.
In short, while at times disappointing, this book does contain ideas worth
reading as well as interesting stimuli. In
addition, the book provokes fruitful,
lively discussions, as experienced first
hand in my research group, which may
also be quite an achievement.
Robert Berger
Frankfurt Institute for Advanced Studies
(FIAS)
Universit:t Frankfurt am Main (Germany)
DOI: 10.1002/anie.200585339
Angew. Chem. Int. Ed. 2006, 45, 5243 – 5244
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