ΑW|L@½Ζ³Ν| Rev. High Pressure Sci. Technol. 8-2,86-95(1998) |
Theoretical Models in High Pressure Reaction Kinetics: from Empirical Correlations to Molecular Dynamics |
N. Weinberg |
A variety of theoretical methods is currently
available for the analysis of the effects
of high pressures on reaction kinetics,
ranging
from simple empirical correlations
to sophisticated
molecular dynamics simulations. Most
of them
operate within the framework of the
transition
state theory where the concept of activation
volume naturally emerges as the pressure
derivative of the activation Gibbs
energy.
Different models of activation volumes
are
discussed, as well as the effects of
high
pressures on reaction profiles, temperature-dependent
effects of high pressures, and effects
of
equilibrium and nonequilibrium solvation.
[high pressure kinetics, activation volume, reaction profile, solvent effect, nonequilibrium solvation] |
Department of Chemistry, University College of the Fraser Valley, Abbotsford, BC, V2S 7M9, Canada and Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada |
ΑW|L@½Ζ³Ν| Rev. High Pressure Sci. Technol. 8-2,96-103(1998) |
Molecular Theories of Partial Molar Volume |
F. Hirata1,2, T. Imai2 , and M. Irisa3 |
Two main streams in the molecular theories
for partial molar volume are reviewed.
The
first stream is based on the scaled
particle
theory of liquids and its extension
to polyatomic
molecules; This has been used successfully
in determining the solvation free energy
of non-polar solutes in water. The
second
method employs the Kirkwood-Buff solution
theory. This method is coupled to the
integral
equation theory of molecular liquids
to calculate
the partial molar volume of polyatomic
molecules.
The dependence of the partial molar
volume
on conformational change of butane
and a
tripeptide is examined based on the
methods.
[partial molar volume, scaled particle theory, Kirkwood-Buff theory, RISM theory, butane, peptide, water] |
1 Department of Theoretical Study, Institute
for Molecular Science, 38 Nishigonaka, Myodaiji,
Okazaki 444-8585 2 Department of Functional Molecular Science, The Graduate University for Advanced Studies, 38 Nishigonaka, Myodaiji, Okazaki 444-8585 3 Faculty of Computer Science and Engineering, Kyushu Institute of Technology, 680-4 Kawazu Iizuka 820-8502 |
ΑW|L@½Ζ³Ν| Rev. High Pressure Sci. Technol. 8-2,104-110(1998) |
Organic Reactions at High Pressure |
Frank-Gerrit Klarner* and Frank Wurche* |
The utility of high pressure for the understanding
of chemical reactions and its applications
in organic synthesis is demonstrated
for
pericyclic reactions (cycloadditions,
Cope
rearrangements, electrocyclizations
and intramolecular
Diels-Alder reactions). With the example
of the peptide coupling it is shown
that
pressure is a valuable tool for the
control
of other reactions than pericyclic
reactions,
too. [Cycloadditions, packing coefficients, product selectivity, supramolecules, thermally labile compounds, peptide coupling] |
Institut fùr Organische Chemie, Universität GH Essen. Universitätsstr, 5,D-45117 Essen, Federal Repabric of Germany |
ΑW|L@½Ζ³Ν| Rev. High Pressure Sci. Technol. 8-2,111-120(1998) |
High Pressure - a Useful Parameter for Catalysis? |
Oliver Reiser |
The scope and limitation of high pressure
for the catalysis of organic reactions
is
evaluated. This article focuses on
Lewis
acid (cycloadditions, epoxide openings,
Horner-Wadsworth-Emmons
reactions) and palladium catalyzed
(Heck-reaction,
[3+2] cycloadditions) reactions. Aspects
of reactivity (turnover frequencies
and turnover
rates) as well as selectivity (chemoselectivity,
regioselectivity, diastereo- and enantioselectivity)
under the influence of pressure will
be discussed.
[catalysis, organic reaction, cycloaddition, Lewis acid, palladium, Heck-reaction, alkenylation] |
Institut fúr Organische Chemie, Universität
Regensburg, Universität sstr. 31, 93053
Regensburg, Germany. e-mail: Oliver.Reiser@chemie.uni-regensburg.de |
_Ά Rev. High Pressure Sci. Technol. 8-2,121-123(1998) |
Raman Studies on Solid CO2 and N2 with Excess He at Pressures up to 40 GPa |
A. P. Jephcoat and H. Olijnyk |
Raman spectra of CO2 and the van-der-Waals ccompound He(N2)11 were obteined rnder nearly hydrosstatic
pressures up to 40 GPa. The pressure induced
changes of the librational spectra suggest
thea solid CO2 does not transform directly from phase-1
(cubic Pa3) to phase-III(orthorhombic Cmca).
An intermediate phase-IV. which my involve
onlly minor modifications of phase-I. is
formed prior to the traansition to Cmca structure.
Phase IV and III coexist over some present
range. The pressure shifts of all four Raman
active librons of phase-III were determined
over a wide pressure raange and are compared
to previous theoretical results. Spectra
of external and internal modes the van-der-Waals
compound He(N2)II are very similar to those of e-N2 and imply a clise relationship between the
structures of He(N2)II and e-N2 . The observed splitting of the main vibron
of iisotooic species 14N-15N indicates that in addition to factor-grooup
interactions site effects are responsible
for the observed splittings of the 14N2 main vibron of He(N2)II. [molecular crystals, vibrational spectroscopy, high pressure, Phase transitions] |
Department of Earth sciences, University of Oxford, Oxford, OXI 3PR, UK |
ΐ±|Cg Rev. High Pressure Sci. Technol. 8-2,124-126(1998) |
OpX[Uπp’½ΕΜΜSjIvͺ(XΞΎ@)ΜΈx» High Time-Resolved Hugoniot Measurement by the Inclined-Mirror Method@using a Long-Pulsed Laser |
ΰμ³a*A^Ί@Ξ UCHINO Masakazu MASHIMO Tsutomu |
We produced a long-pulsed dye laser with
no Q-switch for the shock-wave measurement
or time-resolved spectroscopy under shock
compression of solids. The average output
power of this laser was larger than 13 kW
(effective pulse duration ; `50 µs).
This laser has been used as a light source
for the Hugoniot measurement of solids by
the inclined-mirror method combined with
a rotating-mirror type streak camera. It
was confirmed that the time resolution of
Hugoniot measurement increased to higher
than 1 ns. [long-pulsed laser, shock compression, Hugoniot measurement, inclined-mirror method] |
§860-8555@F{s―2-39-1 F{εwHwΥGlM[ΐ± High Energy Rate Laboratory, Faculty of Engineering, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555. *»§807 -0831@kγBsͺ¦Όζ₯Ό3-6-1 ͺ§HΖZpZ^[@Bdq€ Fukuoka Industrial Technology Centor, 3-6-1 Norimatsu, Yahatanishi-ku, Kitakyusyu, Fukuoka 807-0831. |
§606-0805
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