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Book Review Introduction to Molecular Dynamics and Chemical Kinetics. By G. D. Billing and K. V. Mikkelsen

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These chapters are followed by a presentation of other methods of studying
coordination compounds (Chapter 12),
including IR, Raman, NMR, NQR,
EPR, photoelectron spectroscopy, cyclovoltammetry, and X-ray diffraction.
Chapters 13 and 14 cover the thermodynamics and reaction kinetics of coordination compounds, respectively. The last
three chapters are devoted to bonding in
cluster compounds, some aspects of
bioinorganic chemistry, and an introduction to solid state theory. Here again the
treatment of bonding in clusters and in the
solid state is presented in a clear and convincing manner. In addition, the author
supplies 14 appendixes that cover such
topics as: the conformation of chelate
rings, the VSEPR model, an introduction
to group theory, the Russell-Saunders
coupling scheme, ligand o group orbitals
of an octahedra1 complex, Tanabe-Sugano diagrams, group theoretical aspects
of band intensities, magnetic susceptibility, high temperature superconductors,
and bonding between a transition metal
atom and a C,R, ring.
In general, as mentioned above, the
presentation of the chapters dealing with
bonding theory and its direct application
(spectral and magnetic properties) is entirely suitable for students of inorganic
chemistry. However, the title of the book
is much more general, since in focussing
on physical inorganic chemistry it includes other aspects in addition to bonding and related properties. There are
many more physical chemistry topics addressed in the other chapters that are difficult to understand from a coordination
chemistry point of view. Unfortunately,
the treatment of topics not related to
bonding, such as other methods of studying coordination compounds (Chapter
12), reaction kinetics of coordination
compounds (Chapter 14), and some aspects of bioinorganic chemistry (Chapter
16), is not satisfactory. There are so
many important physical aspects that
needed to be covered in these chapters,
but the treatment is too superficial and
does not meet the standard set by the other, bonding related, chapters. Bonding is
certainly important in coordination
chemistry, but reactivity is just as important and should be treated equally thoroughly.
The technical quality of the presentation is excellent, the figures are very clear,
and at the end of each chapter there are
suggestions for further reading, as well as
a series of exercise problems. The author
has filled the gap between physical and
inorganic chemistry in an impressive way,
and the book is highly recommended to
654
all students working in coordination
chemistry.
Rudi van Eldik
Institut fur Anorganische Chemie
der Universitat Erlangen-Nurnberg
Erlangen (Germany)
Introduction to Molecular Dynamics
and Chemical Kinetics. By G. D.
Billing and K. V. Mikkelsen. Wiley,
Chichester, 1996. 104 pp., hardcover
& 40.00.-ISBN 0-471-12739-6
This book is described on the back of
the dustcover as “the most complete introduction available to molecular dynamics and the calculation of rate of reaction”. In their preface the authors explain
where they start out from and what they
aim to achieve. Whereas most standard
works on physical chemistry merely
sketch the basic ideas of reactive scattering and the theory of the transition state,
their approach was to begin by explaining
these concepts more precisely, and use this
as a basis for what follows. According to
the authors, the distinctive feature of this
book is that it also develops the concepts
of molecular dynamics and reactions in
solution. With this approach, one should
then be able to consider reactions in the
gas phase, on surfaces, and in solution in
relation to each other.
In fact there is as yet no suitable textbook to explain and guide the student
through the important concepts of the dynamics of elastic, inelastic, and reactive
collisions, classical molecular dynamics,
the theory of the transition state, and
stochastic effects in solution. There are a
number of excellent introductions to these
individual subjects, but before the student
goes into any one of these in detail it is
certainly desirable to have a clear overall
understanding of the many different aspects of reaction dynamics. To cover all
that in a single semester is a very ambitious program (this introductory treatment is based on the authors’ course of
lectures for third-year physical chemistry
students), and one has to concentrate on
certain essential aims. Thus, the basic concepts and purpose of each area studied
must be presented concisely, and the essential foundation knowledge must be
conveyed clearly and accurately, without
unnecessary formal ballast. The special
attraction and value of a good survey is
that it should give the student an appreciation of the relative importance of the various topics, their interrelationships, and
their common features.
8 VCH Verlagsge.yellschafimbH. 0-69451
Wrinheim, 1997
With these expectations in mind, we
open the book and find that it consists of
16 chapters. First some important concepts of reactive scattering are introduced : interaction potentials, relative motion, and the collisional approach. Next
there are several chapters on the theory of
the activated complex: partition functions, transition state theory, unimolecular reactions. The authors then return to
the question of time-dependence, with
chapters on classical dynamics and nonadiabatic transitions. The above topics
are covered in 59 pages. There is then a
slightly longer section (63 pp.) on surfaces
and reactions in solution (with the main
emphasis on the latter): surface kinetics,
chemical reactions in solution, solvent effects, models for reactions in solution,
Kramers’ theory, and electron transfer. In
addition each chapter contains a brief, but
adequate and mostly well-chosen, list of
references, and a number of exercises.
There is an appendix containing integrals
and functions, an explanation of the
Laplacian transformation, basic aspects
of the statistical mechanics of systems in
equilibrium, and notes on dielectric polarization and solvation. Lastly there are
some hints for solving the exercise problems. The whole book is in the style of
brief lecture notes. Set up like stepping
stones for exploring the various topics,
and some of the essential steps are treated
in the form of exercises.
Unfortunately, one is seldom aware of
the internal structure, and this can lead
to confusion in view of the abbreviated
style of presentation. An example of this
is seen in the chapter on the relative motion of two colliding particles. Here the
introductory section defines the total momentum and the relative velocity, and expresses the velocity vectors of the two
particles in these terms. Introduction to
kinetic energy then leads to a term that
later turns out to be the kinetic energy of
the center of mass. Only then do the authors introduce the relative positional vector and the positional vector for the mass
center. From the introductory discussion
of the translational momentum of a particle, by involving the total and relative
momenta and differentiating with respect
to time, the authors then obtain the force
as a function of distance (mentioned here
for the first time, with the implicit assumption that no external fields are
present), and hence the equation of motion for the relative positional vector.
Next the kinetic energy for the relative
motion is introduced, expressed in terms
of the time-variation of distance and
angle. Then the authors present us with a
new form by introducing, without expla-
0570-0833/97/3606-0654$17.50+ .SO10
Angew. Chem. Int. Ed. Engl. 1997, 36, N o . 6
BOOKS
nation, an initial condition for this energy,
with an impact parameter. This contains
an expression represented by the symbol
L , which is the contribution of the orbital
angular momentum. The authors then
derive an expression for an effective potential.
This procedure is confusing. Here the
most natural order should instead be as
follows: First. the potential and kinetic
energies are written as functions of the
laboratory coordinates and velocities. A
transformation to the center of mass separates its kinetic energy. Next comes a
transformation to the relative position
and its velocity; both are then expressed in
polar coordinates and angular velocity.
Formation of the (conjugated) orbital angular momentum L gives an expression of
the angular velocity by L. At this point
one changes to a Hamiltonian description
with regard to the orbital angular movement. Conservation of L allows its description by the initial conditions; finally
an effective potential is obtained.
As a second example let us consider the
sequence of steps in developing expressions for the effect on a chemical reaction
of the fluctuating forces caused by the solvent. First the diffusion coefficient D ,is
introduced by the expression for the current density for the molecular species i,
J , = - C,Digradp,/R1: This is then used
to derive Fick‘s first law. There then follows a section on diffusion as a random
walk, without mentioning that here the
transition probability is shared in equal
parts with the nearest neighbors. However, the identification of the diffusion coefficient has to wait until Fick’s second
law is treated in the next section. In another section Brownian motion is treated in a
formal way, which makes it difficult to
understand. Later. much space is devoted
to the diffusion (of position and velocity)
in a potential, even including a derivation
of the Klein-Kramers equation for a
Brownian oscillator. Both these topics are
actually treated in a more easily understandable way in the first five pages of
Kramers’ original paper (Physicu 1940,
7). Moreover. the authors have failed to
include the extension to the case of high
frictional coefficients (the Smoluchowski
equation), which would have led on
naturally to Fick’s second law.
The figures d o not always help the reader’s understanding. In the chapter o n classical dynamics. coordinate systems for describing the motion of B-C relative to A
are shown. One coordinate system has A
as its origin, and the figure shows the mass
centre of B-C and the relative position
vector. But there is also a second coordinate system with its origin at the mass cenAngcw Chrm. Int. G I . EngI. 1991, 36, No. 6
ter of B-C, and a special notation is used
to describe positions in this system. However, in this context the second system is
completely unnecessary! Another figure
in this chapter purports to show how the
coordinates transform when the reference
frame is moved from the mass center of
B-C to that of A-C. The relative positions of A, B, and C should be the same in
the two coordinate systems, but the figure
shows two different configurations! A figure in the chapter on chemical reactions in
solution intends to visualize a “Brownian
particle”. This consists of a dumb-bell
within a frame, and it is surrounded by
concentric rings whose significance is
never established. These are just a few of
the many figures that convey nothing, are
likely to mislead, o r are simply incorrect.
The overall impression is as though, in
some strange way, the book has been written in a succession of forward leaps alternating with backward steps, and it also
contains many small errors. Consequently, reading through it is unnecessarily
hard work. It therefore seems rather unlikely to help kindle students’ enthusiasm
for microscopic reaction dynamics and
chemical kinetics.
Nikoluus P. Emsting,
Nils Heineking
Institut fur Physikalische
und Theoretische Chemie
der Humboldt-Universitat
Berlin (Germany)
Directory of Solvents. Edited by B. P .
Whim and P . G . Johnson. Blackie/
Chapman and Hall, London, 1996.
612 pp., hardcover S 149.00.-ISBN
0-7514-0245-1
If one needs to choose a suitable solvent
for a particular chemical reaction o r technological process from the vast range
nowadays available, on the basis of objective criteria, the task of extracting the necessary chemical, physical, toxicological,
and other data from the literature can often be very laborious. The handbook reviewed here should prove to be a valuable
aid in such cases, especially when organic
solvents are to be used in technological
processes.
Part 1 of the book, entitled “Solvents”,
treats the more general aspects. The eight
chapters (the work of nine authors altogether) discuss the criteria for making a
correct choice of solvent and using it most
effectively. In a short introductory chapter (“Introduction to Solvents”) P. Davison explains the classification of solvents,
describes how they are manufactured, and
0 VCH Verlugsgesellschuft mbH, 0-69481 Weinheim, 1997
discusses the quantities consumed, their
environmental acceptability, and their
toxicity to humans. Chapter 2, “Solvent
Action and Measurement”, by W. C.
Aten, is mainly concerned with intermolecular solvent - solvent interactions,
the Hildebrand and Hanson solubility
parameters, and the solvation power,
volatility, and viscosity of solvents. The
next chapter, also by Aten, is entitled
“Choosing a Solvent : Practical Advice”,
and relates particularly to the choice of
solvents or solvent mixtures for manufacturing solvent-borne and water-based
paints. In Chapter 4, “Solvent Flammability and Reactivity Hazards”, R. L.
Rogers explains the numerical properties
such as flashpoint and explosible limits
that determine the flammability of a solvent, an aspect of particular importance
when dealing with large quantities, and
describes the procedures that are demanded by legal regulations. In Chapter 5,
“Protection of Health”, A. M. Moses describes the various health hazards that can
arise in handling solvents, and the precautions for minimizing them. Aspects that
receive special attention include the toxicities of particular solvents or groups of
solvents, the correct preparation of safety
data sheets, measures of inhalation toxicity (e.g., MAK and T R K values), and the
legislation governing these matters in the
European Union, the U K and the USA.
Chapter 6, by I. D. Dobson, A. S. McCormick, and D. A. King, is entitled “Solvents in the Environment”. The authors
describe the damaging effects of solvents
on the earth’s atmosphere, such as the destruction of ozone in the stratosphere by
CFCs, and the toxic effects on aquatic and
terrestrial environments, which are still
insufficiently studied. In Chapter 7, “Solvent Transport, Storage, Recovery and
Disposal”, G. P. Howe explains the classification of solvents and the international
regulations governing their transportation, storage, recovery, and disposal, and
describes the most important methods
that have been developed for the last two
of these. In the last chapter of this part,
under the title “Major Solvent Applications Overview”, J. R. Kelsey summarizes
the most important technological applications of organic solvents. In Europe in
1994 the manufacturing areas that consumed the largest quantities of solvents
(leaving aside their use as chemical intermediates) were, in descending order of
bulk: paints of all kinds, pharmaceuticals
and agrochemicals, printing inks and adhesives of all kinds, cleaning fluids, and
household products.
Part 2 of the handbook (“Solvent
Data”) occupies the greater proportion,
0870-OS33/97/3606-06SSd 17.8Oi .SO/O
655
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