Brief Research Description as listed in home pages of
the Department of Chemistry.
Research results have been documented in
Publications & Patents
The theoretical and computational studies are generously supported by
MU Campus Computing.
The Silicon Graphics Computing
Resources at MU include a Silicon Graphics Power Challenge L
supercomputer with 8 R10000 processors. This system is called Shiva
and it is our main resource for performing high level ab initio
quantum-chemical studies. Senior computer programmer analyst
assists with the installation, maintenance, and optimization of the
various codes we run on Shiva. Our local computing environment in the
group also includes Silicon Graphics systems and
has helped us keeping the system software on our Indigo up-to-date.
The figure (click to enlarge) shows an electron density color-coded
gradient vector field of the electrostatic complex formed betweeen benzyl
cation and dinitrogen. The plot was generated with software written by
David Farmer and Rainer Glaser. The new technique for the graphical
analysis of electron density distributions was employed recently in a
paper entitled "The Cation-Dinitrogen Interaction in
"Benzyldiazonium Ion". Preferential Electrostatic
Complex Formation and Dinitrogen Catalysis of Benzyl Cation Rotational
Automerization " which was written by Rainer Glaser and David Farmer
and published in Chem. Eur. J. 1997, 3, 1244-1253.
The article appeared in the August issue and our contribution was featured
on the cover of
the August issue of Chemistry. We also recently presented a poster
Analysis of Cation-Dinitrogen Interactions with Density Color Coded
Gradient Vector Fields" at an ACS Meeting.
Density Color-Coded Gradient Vector Fields
Dr. Rainer Glaser and David Farmer
Department of Chemistry
We are interested in the numerical simulation of crystals. The success of
the quest for novel crystalline materials with interesting electric and
optical properties is largely determined by the mode in which the molecules
aggregate in the solid state. In crystal engineering one attempts to design and
realize lattice architectures in a rational fashion. To do so one needs to know
about intermolecular interaction energies. In this context, we are developing
methods for the quantitative analysis of electrostatic interactions in
poster of a recent presentation on the topic "Mathematical Derivation
of an Alternative Fast Multipole Method" are available.
Numerical Simulation of Molecular
Dr. Rainer Glaser, Department of Chemistry
Don Steiger and Dr. Calvin Ahlbrandt, Department of Mathematics
Organic Crystalline Ferroelectic
Dr. Rainer Glaser and Michael Lewis
Department of Chemistry
By way of a combination of ab initio computations and experimentation, we
are designing NLO chromophores as the building blocs of organic
crystalline ferroelectic materials. A few prototypes have been reduced
to practice and current efforts are directed at increasing the lattice
energies. The picture shows a pair of perfectly dipole parallel-aligned
azines molecules. (Click the picture to download a pdb file for viewing
with Rasmol.) These pairs assemble in the solid state in such a way as to
result in near-perfect dipole parallel alignment of the crystal. These
asymmetrically substituted azines therefore not only are NLO chromophores
but they also pack in such a way as to render the crystal NLO active without
any need for electric field poling. Unprecedented NLO chromophore
densities have been realized in this way. The first prototype of a
near-perfect organic ferroelectric was featured as the
Molecule of the Month, December 1997.
This feature can be viewed both as a
and as an
the Month page is maintained by Paul May of Bristol University.
The combination of physical-organic and theoretical methods allows one to
carry electronic structure analysis to a level that could not be reached
by either one approach alone. We have been focusing on studies of
"Opposing Sign Reaction Constants in Dual Substituent Parameter (DSP)
Relations". The abstract is available online of a
that was presented at the 30th Midwest Theoretical Chemistry Conference,
University of Illinois, Urbana-Champaign, May 22-24, 1997.
For more detail, please refer to a first communication with
the title "Electron Density Relaxation and Opposing Sign Reaction Constants
in Dual Substituent Parameter Relations in Dediazoniation Reactions" has
recently been published in Angewandte Chemie (Angew. Chem. Int.
Ed. Engl. 1997, 36, 2210-2213).
sigmaF rohF +
with rohR / rohF < 0
Dual Substituent Parameter Relations
in Dediazoniation Reactions.
Dr. Rainer Glaser and Stephanie Nelson, MU, Department of Chemistry
Dr. Heinrich Zollinger, ETH Zuerich, Switzerland
The deamination of guanine in vivo and in vitro has long
been thought to involve the hydrolysis of an intermediate guanine
diazonium ion to form xanthine. The group of Makino found that
substantial amounts of oxanosine also are formed in this deamination
and this experimental result put in question the generally accepted
deamination mechanism for guanine. Research in the Glaser group revealed
that the dediazoniation of guanine is accompanied by a facile pyrimidine
ring opening reaction. This discovery suggests a hypothesis for the
formation of oxanosine and xanthine at the same time. The mechanism
proposal has been published in a communication entitled "Pyrimidine Ring
Opening in the Unimolecular Dediazoniation of Guanine Diazonium Ion. An ab
Initio Theoretical Study of the Mechanism of Nitrosative Guanosine
Deamination" in the Journal of the American Chemical Society
(J. Am. Chem. Soc. 1996, 118, 10942-10943). Current
research aims at establishing the mechanism of guanine deamination via a
combination of experimental and theoretical methods.
Deamination of Guanine.
Dr. Rainer Glaser and Sundeep Rayat
MU, Department of Chemistry
We are studying the structures and vibrational properties of biphenyl and
polyphenyls and of their aggregates. The results of these studies will
answer questions relating to arene-arene interactions and might help to
explain Raman intensity changes observed in the solid as a function of
Structures and Vibrational Properties of
Dr. Rainer Glaser, MU, Dept. of Chemistry
Dr. Meera Chandrasekhar
and Dr. Sushismita Guha, MU Dept. of Physics & Astronomy
Nucleophilic Substitution of Diazonium Ions.|
Dr. Rainer Glaser and Rhonda Walsh, MU, Department of Chemistry
Asymmetrization of Azines and
Dr. Rainer Glaser and Sarah Meyer, MU, Department of Chemistry
Optical Properties of Azines.|
Dr. Rainer Glaser and Heather Tluczek, MU, Department of Chemistry